Technical Report - Vanadium Pentoxide - CAS 1314-62-1 - HSE

Technical report: divanadium pentaoxide; vanadium pentoxide

1

Agency technical report on the classification and labelling of

divanadium pentaoxide; vanadium pentoxide

EC Number: 215-239-8 CAS Number: 1314-62-1

Health and Safety Executive Chemicals Regulation Division

Redgrave Court Merton Road

Bootle L20 7HS [email protected]

Date: July 2021

mailto:[email protected]


2

Contents Brief summary ........................................................................................................................... 3

Introduction ............................................................................................................................... 4

Overview of current and proposed classification and labelling ................................................ 4

General substance information ................................................................................................. 6

Background ................................................................................................................................ 6

Scientific assessment of the physical, human health and environmental hazard classes ........ 7

Physical Hazards ........................................................................................................................ 7

Health Hazards .......................................................................................................................... 7

Acute toxicity ......................................................................................................................... 7

Specific target organ toxicity – single exposure (STOT SE).................................................. 10

Skin corrosion/irritation ...................................................................................................... 10

Serious eye damage/irritation ............................................................................................. 11

Respiratory sensitisation ..................................................................................................... 11

Skin sensitisation ................................................................................................................. 12

Specific target organ toxicity – repeated exposure (STOT RE) ............................................ 12

Germ cell mutagenicity ....................................................................................................... 14

Carcinogenicity .................................................................................................................... 18

Reproductive toxicity ........................................................................................................... 22

Aspiration hazard ................................................................................................................ 29

Environmental hazards ............................................................................................................ 29

Other hazards .......................................................................................................................... 29

Overall conclusion ................................................................................................................... 30

References ............................................................................................................................... 31

Glossary of terms used in Agency technical reports ............................................................... 32


3

Brief summary

The conclusion of the Agency technical report is that divanadium pentaoxide; vanadium pentoxide meets the classification criteria for:

Carc. 1B; H350 (May cause cancer) Muta. 2; H341 (Suspected of causing genetic defects) Repr. 2; H361fd (Suspected of damaging fertility. Suspected of damaging the unborn child) Lact.; H362 (May cause harm to breast-fed children) Acute Tox. 3; H301 (Toxic if swallowed) with an ATE of 220 mg/kg bw

Acute Tox. 2; H330 (Fatal if inhaled) with an ATE of 0.05 mg/l (dusts or mists) STOT RE 1; H372 (Causes damage to the respiratory tract through prolonged or repeated exposure via inhalation)

The existing mandatory classification for STOT SE 3 and Aquatic Chronic 2 (not assessed in this technical report) should be retained.

Is this in agreement with the RAC opinion? YES At the time of publication, this mandatory classification and labelling has not been agreed and/or adopted in Great Britain. This technical report only considers the following hazard classes: acute toxicity, respiratory sensitisation, germ cell mutagenicity, carcinogenicity, reproductive toxicity and specific target organ toxicity – repeated exposure. These were the only hazard classes considered in the EU CLH report and RAC opinion.


4

Introduction

Under Article 37 of the GB CLP Regulation1, the Agency2 is required to produce a technical report for each substance on which the Committee for Risk Assessment (RAC) of the European Chemicals Agency produces an opinion3. This technical report documents an independent scientific assessment, conducted by HSE technical specialists, of the classification and labelling of divanadium pentaoxide; vanadium pentoxide. Table 1. Information considered in the scientific assessment

Document Included in assessment

EU CLH report Yes

Annexes to the EU CLH report Yes

RAC opinion Yes

Background document Yes

Information submitted during the EU public consultation process (RCOM table, including attachments)

Yes

RAC minority opinion(s) Yes

Other information: no

This information has been evaluated against the classification and labelling criteria set out in the GB CLP Regulation.

1The retained CLP Regulation (EU) No. 1272/2008 as amended for Great Britain 2 HSE acting in its capacity as the GB CLP Agency 3 Under Article 37(4) of Regulation (EU) No 1272/2008 on classification, labelling and packaging of substances and mixtures


4

Overview of current and proposed classification and labelling

Table 2. Current and proposed classification and labelling

Classification

Labelling

Index No.

International Chemical

Identification

EC No.

CAS No.

Hazard Class and Category Code(s)

Hazard Statement Code(s)

Pictogram, Signal Word

Code(s)


Suppl. Hazard

Statement Code(s)

Specific Concentration Limits, M-

factors

Notes

GB MCL List entry

023-001-00-8

Divanadium pentaoxide; vanadium pentoxide

215-239-8

1314-62-1

Muta. 2 Repr. 2 Acute Tox. 4 * Acute Tox. 4* STOT SE 3 STOT RE 1 Aquatic Chronic 2

H341 H361d*** H332 H302 H335 H372** H411

GHS07 GHS08 GHS09 Dgr

H341 H361d*** H332 H302 H335 H372** H411

EU dossier submitter’s proposal

023-001-00-8


215-239-8

1314-62-1

Add Carc. 1B Lact. Modify Muta. 1B Repr. 1B Acute Tox. 1 Acute Tox. 3 STOT RE 1

Add H350 H362 Modify H340 H360Fd H330 H301 H372 (respiratory tract, inhalation)

Add GHS06 Retain GHS08 Dgr Remove GHS07

Add H350 H362 Modify H340 H360Fd H330 H301 H372 (respiratory tract, inhalation)

Add inhalation: ATE = 0.005mg/l (dusts or mists)

oral: ATE = 100mg/kg bw

EU RAC opinion

023-001-00-8


215-239-8

1314-62-1

Carc. 1B Muta. 2 Repr. 2 Lact. Acute Tox. 3

H350 H341 H361fd H362 H301


H350 H341 H361fd H362 H301

inhalation: ATE = 0.05 mg/l (dusts or mists)


5

Classification

Labelling

Index No.

International Chemical

Identification

EC No.

CAS No.

Hazard Class and Category Code(s)


Pictogram, Signal Word

Code(s)


Suppl. Hazard

Statement Code(s)

Specific Concentration Limits, M-

factors

Notes

Acute Tox. 2 STOT RE 1

H330 H372 (respiratory tract, inhalation)

H330 H372 (respiratory tract, inhalation)

oral: ATE = 220 mg/kg bw

Agency technical report conclusion

023-001-00-8


215-239-8

1314-62-1

Carc. 1B Muta. 2 Repr. 2 Lact. Acute Tox. 3 Acute Tox. 2 STOT RE 1

H350 H341 H361fd H362 H301 H330 H372 (respiratory tract, inhalation)


H350 H341 H361fd H362 H301 H330 H372 (respiratory tract, inhalation)

inhalation: ATE = 0.05 mg/l (dusts or mists) oral: ATE = 220 mg/kg bw

Resulting MCL entry on GB MCL list

023-001-00-8


215-239-8

1314-62-1

Carc. 1B Muta. 2 Repr. 2 Lact. Acute Tox. 3 Acute Tox. 2 STOT RE 1 STOT SE 3 Aquatic Chronic 2

H350 H341 H361fd H362 H301 H330 H372 (respiratory tract, inhalation) H335 H411


H350 H341 H361fd H362 H301 H330 H372 (respiratory tract, inhalation) H335 H411

inhalation: ATE = 0.05 mg/l (dusts or mists) oral: ATE = 220 mg/kg bw


6

General substance information

Active substance in Plant Protection Products: ☐

Active substance in Biocidal Products: ☐

Chemical registered under REACH: ☒

Background

Divanadium pentaoxide or vanadium pentoxide is the principal starting material for the production of vanadium compounds, as an intermediate in the production of vanadium and steel alloys and as a catalyst in the oxidation of sulphide to sulphate and alcohol to acetaldehyde. It is also used in catalytic converters, for the manufacture of yellow glass that inhibits transmission of ultraviolet light, in photographic developing solutions and in dyeing applications (the production of aniline black dye, to dye ceramics, and in colouring textiles). Some vanadium compounds are used for pharmaceutical purposes. Vanadium pentoxide was originally classified according to the Classification and Labelling of Dangerous Substance Directive (Dir. 67/548/EEC) and then adapted according to Regulation (EC) No. 1272/2008 (CLP Regulation) (CLP00). Based on a translation of the original classification, the current Annex VI entry for divanadium pentaoxide (vanadium pentoxide) includes Muta. 2 (H341), Repr. 2 (H361d***), Acute Tox. 4* (H302; H332), STOT SE 3 (H335), STOT RE 1 (H372**) and Aquatic Chronic 2 (H411). The proposal by the dossier submitter (DS), pending agreement from RAC and the European Commission was to retain the existing classification as STOT SE 3 (H335) and Aquatic Chronic 2, add Carc. 1B (H350) and Lact (H362) modify the existing Annex VI entry for mutagenicity, reproductive toxicity, acute toxicity and STOT RE to Muta. 1B (H340), Repr. 1B (H360Fd), Acute Tox 1 (H330), Acute Tox 3 (H301) and STOT RE 1 (H3372 (respiratory tract, inhalation). A read-across approach from other pentavalent vanadium compounds has been used for some endpoints. Data generated with sodium metavanadate (CAS-No.: 13718-26-8) and ammonium metavanadate (CAS-No.: 7803-55-6) have been used as:

• supporting evidence regarding adverse effects on male sexual function and fertility,

• key information for adverse effects on development (source substance: ammonium metavanadate and sodium metavanadate)

• key information for adverse effects on or via lactation.


7

The read-across proposal was presented by the DS in Annex 2 to the CLH report and the data from sodium metavanadate and ammonium metavanadate considered as part of the RAC opinion. RAC considered the read-across appropriate.

Scientific assessment of the physical, human health and environmental hazard classes

Physical Hazards

Not assessed in the CLH report or RAC opinion

Health Hazards

Acute toxicity

Classification agreed by RAC: Vanadium pentoxide is currently classified for acute toxicity cat 4 for exposure via the oral and inhalation routes. In the CLH report, the DS proposed that this should be amended to cat 3 for acute oral toxicity and cat 1 for acute inhalation toxicity. Vanadium pentoxide is not currently classified for acute dermal toxicity, and there was no proposal to change this in the CLH report. Oral Twelve acute oral toxicity studies were presented in the CLH report and considered by RAC. These were performed in rats, mice or rabbits and reported LD50 values between 10.4 and 714.7 mg/kg bw. Only three studies, all performed in rats (Sprague Dawley), were considered reliable (Klimisch score 1). These studies were predominantly used in the assessment of the acute oral toxicity of vanadium pentoxide. All three studies were performed according to OECD TG 401 and to GLP. Each tested different forms of vanadium pentoxide with an analytical purity of vanadium between 55.6-56.25% and a calculated purity of vanadium pentoxide of between 97.86 and 100.04%. These studies gave LD50 values in the range 221.1 – 715.7 mg/kg bw with females being more sensitive than males (see Table 3). RAC noted that the LD50 values appeared to be related to the form of vanadium pentoxide tested and the sex of the animals, with the lowest LD50 seen in females following exposure to pulverised technical grade material.


8

Table 3. LD50 values in the three reliable acute oral toxicity studies in rats

Form of vanadium pentoxide LD50 (mg/kg bw)

Males Females Combined

Study 1 Analytical grade pulverised 474.2 466.93 470.67

Study 2 Technical grade fused 715.7 658.4 687.05

Study 3 Technical grade pulverised 313.8 221.1 267.45

In all of the above studies, the LD50 values from males would warrant classification in category 4 for acute oral toxicity (300 <category 4 ≤2000 mg/kg bw) as would those for females from studies 1 and 2. However, based on the lowest LD50 value, which was obtained from females exposed to pulverised technical grade vanadium pentoxide, the DS proposed classification in category 3 (50 <category 4≤300 mg/kg bw). RAC supported the DS’s proposal, noting that the combined LD50 for males and females from study 3 also met the criteria for classification in category 3. In addition, RAC considered that, in a weight of evidence approach, this proposal was supported by the results from some of the low reliability studies. RAC did not support the DS’s proposal to set an ATE value of 100 mg/kg bw based on the converted ATE point for category 3 substances, considering this overly conservative. Instead they proposed that the ATE should be based on the lowest LD50 value observed in the reliable studies. Consequently, RAC concluded that the ATE for vanadium pentoxide is 220 mg/kg bw. Overall, RAC concluded that vanadium pentoxide met the criteria for classification as Acute tox 3 (H301) with an ATE of 220 mg/kg bw. Dermal Three acute dermal toxicity studies were presented in the CLH report and were considered by RAC. All three studies were performed in rats according to OECD TG 402 and GLP, and used the same forms of vanadium pentoxide as the acute oral toxicity studies (see above). All the studies reported LD50 values of > 2500 mg/kg bw, and therefore RAC concluded that classification for acute toxicity via the dermal route was not warranted. Inhalation Eight acute inhalation toxicity studies were presented in the CLH report, of which five (four in rats and one in mice) were found to be reliable with restrictions (Klimisch score 2) and were considered by RAC for the assessment of acute inhalation toxicity. Three of the studies in rats (Sprague Dawley) were performed according to OECD TG 403 and to GLP. Each of these studies tested a different form of vanadium pentoxide (see section on acute oral toxicity for further details). The LC50 values were in the range 2.21-16.19 mg/l and appear to be related to the sex and the form tested; females appeared to be more sensitive than males, with technical grade pulverised


9

vanadium pentoxide being of higher toxicity compared to the other forms of vanadium pentoxide (see Table 4). Table 4. LC50 values in three acute inhalation toxicity studies in rats

Form of vanadium pentoxide LC50 (mg/l)

Males Females

Study 1 Analytical grade pulverised 11.09 4.29

Study 2 Technical grade fused 16.19 4.04

Study 3 Technical grade pulverised 4.40 2.21

The fourth study in rats (F344) and the study in mice (B6C3F1) tested an aerosolised powder. Both were performed according to OECD TG 436 and to GLP. The LC50 value in rats was 0.25 mg/l (for both males and females). In mice the LC50 values were > 0.5 mg/l in males and < 0.056 mg/l in females, with a combined LC50 for both sexes of 0.28 mg/l (assuming that the LC50 for males was 0.5 mg/l and that the for females was 0.056 mg/l) following a 4 hour exposure. Based on the results of the studies the DS proposed that vanadium pentoxide should be classified as Acute Tox 1 from the LC50 of <0.056 mg/l observed in female mice (most sensitive species and sex) with an ATE of 0.005 mg/l. RAC disagreed, instead proposing classification as Acute tox 2 and an ATE of 0.05 mg/l. In reaching their conclusion, RAC assessed the performance of the different studies, interpretation of the results according to the OECD TG, numbers of animals tested, number of studies in each species and the criteria for classification. The key point of discussion was whether it was appropriate to use the result for female mice from the OECD TG 436 study for classification purposes. According to the TG, lethality for six animals per concentration level should be considered when deciding the LC50 (either three of each sex or six of the more sensitive sex). The OECD TG 436 studies with vanadium pentoxide tested three animals per sex at each dose level and therefore the results from both sexes should be used. On this basis, the LC50 for mice from both males and females is 0.28 mg/l and therefore meets the criteria for classification in category 2 for acute inhalation toxicity. This is the same classification as that obtained for F344 rats using the OECD TG 436 method. While OECD TG 436 does allow for the study to be performed in just the more sensitive sex, this was not done for the vanadium pentoxide investigations. RAC therefore considered that given the low number of female animals (3 rather than 6), it was difficult to establish whether the B6C3F1 females were notably more sensitive than males. A sex difference was indicated based on the OECD TG 403 studies with Sprague Dawley rats, but this was not seen with OECD TG 436 studies with F344 rats. RAC also noted that in a 16-day repeat-dose toxicity (RDT) study (NTP, 2002; details not included in the CLH report), B6C3F1 female mice were not more sensitive than males to vanadium pentoxide by inhalation when tested at a dose level of almost 60% of that used in the acute inhalation toxicity testing according to OECD TG 436 (0.032 mg/l for 6 hours/day vs 0.056 mg/l for 4 hours/day). In the RDT study there was no mortality in


10

females up to 0.032 mg/l, while RAC considered the deaths in males could be attributed to repeat exposures. Overall while RAC noted the sex difference in the toxic effects observed in the B6C3F1 mouse in the OECD TG 436 study, it considered that it was difficult to base the classification on just three animals when the test guideline requires a minimum of six. Furthermore, RAC considered that results from the 16-day RDT study lessened the concern regarding the susceptibility of the female B6C3F1 mice in the acute tox inhalation study. Taking all of this into account, RAC concluded that classification of vanadium pentoxide as Acute Tox 2 (H330) was warranted based on the findings in the OECD TG 436 study for both rats and mice (both sexes combined). RAC also disagreed with the ATE value proposed by the DS, considering it to be unreasonably conservative, particularly when the highest dose levels from the two-year carcinogenicity studies (0.004 mg/l for mice and 0.002 mg/l for rats) were taken into account. Instead, RAC proposed to use the converted ATE value of 0.05 mg/l from Annex I Table 3.1.2 consistent with the classification of vanadium pentoxide as Acute tox 2. Overall, RAC concluded that for acute inhalation toxicity, classification as Acute Tox. 2, H330 was warranted for vanadium pentoxide, with an ATE of 0.05 mg/l (dusts or mists). Classification proposed by the Agency: Oral The Agency agrees with RAC’s assessment of the data. Vanadium pentoxide meets the criteria for classification as Acute Tox 3, H301 with an ATE of 220 mg/kg bw. Dermal The Agency agrees with RAC’s assessment of the data. Vanadium pentoxide does not meet the criteria for classification for acute dermal toxicity. Inhalation The Agency agrees with RAC’s assessment of the data. Vanadium pentoxide meets the criteria for classification as Acute Tox 2, H300 with an ATE of 0.05 mg/l.

Specific target organ toxicity – single exposure (STOT SE)

Classification agreed by RAC: Vanadium pentoxide has an existing classification of STOT SE3. This was not reassessed in the CLH report or RAC opinion.

Skin corrosion/irritation

Not assessed in the CLH report or RAC opinion


11

Serious eye damage/irritation

Not assessed in the CLH report or RAC opinion.

Respiratory sensitisation

Classification agreed by RAC: The DS proposed not to classify vanadium pentoxide for respiratory sensitisation. The data available for assessing this endpoint included one non-guideline sub-chronic inhalation test in cynomolgus monkeys and four studies on workers from vanadium processing industries.

Animal data In a non-guideline study (Klimisch score 2), adult male cynomolgus monkeys were exposed to vanadium pentoxide dust (whole body) for six hours per day on five days per week for 26 weeks. There were two exposure groups; one was exposed to 0.1 mg/m3 for three days and 1.1 mg/m3 for the other two; a second group was dosed as 0.5 mg/m3 for all five days. Challenge doses (0.5 mg/m3 for 6 hours/day) were administered at two-week intervals. Pulmonary function was decreased in both groups exposed to vanadium pentoxide. Acute effects after the pre-exposure challenge with 0.5 and 3 mg vanadium pentoxide/m3 were a concentration-dependent impairment in pulmonary function, characterized by airway obstructive changes (increased resistance and decreased flow). Analysis of respiratory cells recovered from the lung by bronchoalveolar lavage demonstrated that airway obstruction was accompanied by a significant influx of inflammatory cells into the lung. Cytological immunological results test (IgE and IgG analysis) did not indicate allergic sensitisation. Human data Four occupational studies were available from vanadium processing industries. All these reported upper respiratory tract symptoms. However, these appeared to be caused by irritation rather than sensitisation. In one study, a significantly higher number of plasma cells in nasal mucosa samples were reported. RAC considered this finding interesting, as plasma cells derived from B-lymphocytes produce IgE antibodies. However, as there was no more information reported on this finding, and no symptoms related to hypersensitivity were observed, the plasma cell finding on its own was not considered significant. No data were available regarding the skin sensitising property of vanadium pentoxide. Vanadium pentoxide was considered by the registrant as not skin sensitising, based on read-across from vanadium oxide sulphate pentahydrate (vanadyl sulphate) and sodium metavanadate.


12

RAC agreed with the DS that neither the in vivo animal nor human data indicated a respiratory sensitisation potential for vanadium pentoxide and therefore, classification was not warranted.

Classification proposed by the Agency: The Agency agrees with RAC’s assessment of the data. Vanadium pentoxide does not meet the criteria for classification for respiratory sensitisation.

Skin sensitisation


Specific target organ toxicity – repeated exposure (STOT RE)

Classification agreed by RAC: In the CLH report, the DS proposed to update the existing Annex VI entry for vanadium pentoxide from STOT RE 1 (H372**) to STOT RE 1 (H372) and to include the target organ and the route of exposure (respiratory tract, inhalation). This was based on both animal and human data. Animal data Seven animal studies were included in the CLH dossier, those assessed as reliable (Klimisch score 1) or reliable with restrictions (Klimisch score 2) were considered by RAC for the assessment of STOT RE following exposure to vanadium pentoxide. Sub-acute studies In a subacute inhalation study, B6C3F1 mice were exposed to vanadium pentoxide aerosols for 6 hours per day for 16 days at concentrations of 0, 0.25, 1 and 4 mg/m3. At concentrations of 1 mg/m3 and above, lung weights, alveolar histiocytosis, multifocal subacute alveolitis, multifocal granulocytic infiltration and cell proliferation rates were increased. 90-day studies in rats, mice and monkeys In a 90- day study in F344 rats, effects on the respiratory tract were observed. These included:

• Changes in pulmonary function at 4, 8, and 16 mg/m3.

• Minimal to moderate lung fibrosis at ≥ 2 mg/m3.

• Alveolar/bronchiolar epithelial hyperplasia was present at ≥ 2 mg/m3.

• Hyperplasia and metaplasia of the nasal respiratory epithelium at ≥ 4 mg/ m3.


13

• Lung and nasal inflammation were also observed at ≥2 mg/m3 and ≥ 4 mg/ m3

respectively.

In a 90-day study in mice (B6C3F1), the respiratory tract was the primary site of toxicity, with effects seen from 2 mg/m3. These showed an increase in both the range of effects and severity of proliferative lesions with increasing exposure time. The effects included:

• Significantly increased absolute lung weight in male mice exposed to 2 mg/m3.

• Inflammation and alveolar/bronchiolar epithelial hyperplasia at ≥ 2 mg/m3, with lung inflammation and epithelial hyperplasia in all animals at ≥8 mg/m3.

In a sub-chronic study in adult male cynomolgus monkeys (see section on respiratory sensitisation), pre-exposure challenges with 0.5 and 3 mg vanadium pentoxide/m3 produced a concentration-dependent impairment in pulmonary function. This consisted of airway obstructive changes accompanied by a significant influx of inflammatory cells into the lung but no changes indicative for airway hyperreactivity were observed.

Two year studies in rats and mice In a two-year carcinogenicity study in F344 rats, lesions were observed in lungs. These included inflammation, interstitial fibrosis, histiocytosis and hyperplasia (of the alveoli and bronchiole and mostly occurred in a dose dependent manner starting from 0.5 mg/m3 with squamous metaplasia of the alveoli being seen at 2 mg/m3. Effects were also reported on other parts of the respiratory tract; in the larynx inflammation, fibrosis, degeneration, hyperplasia and squamous metaplasia of the respiratory epithelium of the epiglottis were observed from 0.5 mg/m3 while hyperplasia of the respiratory epithelium of goblet cells was seen in the nose. Similar effects were also observed in B6C3F1 mice, mostly in a dose dependent manner starting from 1 mg/ m3. Data from humans

RAC also considered findings from humans. These included respiratory tract irritation, increased numbers of neutrophils in nasal smears, significantly higher number of plasma cells in nasal mucosa samples and other signs of upper respiratory tract inflammation. Although limited, the data from humans support the view that the respiratory tract is a target organ. Conclusion

RAC agreed with the DS that, based on the available data in rats, mice and humans, the inhalation route is relevant, and that the respiratory tract could be identified as the target organ. Minimal to moderate lung fibrosis and hyperplasia were observed in rats in a


14

90-day study from 2 mg/m3 (equal to 0.002 mg/l/6h/day) which is within the guidance value range for Cat. 1 (≤0.02 mg/l/6h/day). Similarly, in a 90-day study in mice the respiratory tract was also the target organ with effects (inflammation and alveolar/bronchiolar epithelial hyperplasia) seen from 2 mg/m3. These increased in severity with longer exposure duration. Similar effects to those seen in the 90-day studies were seen in both rats and mice following exposure for two years. RAC considered the findings on respiratory tract to be toxicologically significant with the potential to produce significant toxicity in humans following repeated exposure. Overall, therefore, RAC agreed with the DS that classification as STOT RE 1, H372 (respiratory tract; inhalation) was warranted for vanadium pentoxide. Classification proposed by the Agency: The Agency agrees with RAC’s assessment of the data. Vanadium pentoxide meets the criteria for classification as STOT RE1 for respiratory tract irritation. The Agency also agrees that the data are sufficient to determine the route of exposure. Classification of vanadium pentoxide as STOT RE 1, H372 (respiratory tract; inhalation) is warranted.

Germ cell mutagenicity

Classification agreed by RAC: Vanadium pentoxide has an existing classification for germ cell mutagenicity category 2 (H341). In the CLH report, the DS proposed to modify this classification to mutagenicity category 1B. The basis for this was positive results from several in vitro micronucleus (MN) tests and comet assays reported in the literature, positive results in a range of studies (mainly from a single research group), an analysis of K-ras mutations observed in alveolar/bronchiolar carcinomas together with elevated phospho-MAPK in carcinoma tissues with K-ras mutations and toxicokinetic data showing that vanadium is distributed to the testes following inhalation and intra-tracheal route of exposure. In vitro studies

Bacterial and mammalian cell mutagenicity studies In vitro, vanadium pentoxide gave negative results in an Ames test (OECD TG 471) with and without S9 mix, a mouse lymphoma assay (OECD TG 476) with and without S9 mix, and a gene mutation assay in Chinese hamster V79 cells without metabolic activation. These studies were considered reliable (Klimisch score 1 and 2 respectively). RAC noted a single in vitro bacterial mutagenicity test that gave a positive response in E. Coli but not in S. typhimurium, but lack of information on the


15

study meant it could not be independently evaluated and therefore RAC gave it no further consideration. Overall, RAC concluded that vanadium pentoxide is not directly mutagenic in vitro. Clastogenicity/aneugenicity Vanadium pentoxide gave some evidence of producing clastogenic/aneugenic effects. Five studies, considered by the DS to be reliable, were reported in the RAC opinion. Three mammalian cell micronucleus tests were included of which two gave negative results, while the third (performed according to OECD TG 487) was positive both with and without metabolic activation. Positive results were also reported in a micronucleus test with cytochalasin B and sister chromatid exchange (SCE), and in a comet assay. In addition, RAC noted three studies with limitations in reporting or study conduct. These studies were from the same research groups as the reliable studies and included a negative chromosome aberration and SCE assay, and two positive Comet assays. Conclusion on in vitro studies Overall based on these data, RAC concluded that vanadium pentoxide can cause chromosomal damage in vitro and postulated that the mechanism could involve a disruption to cell division resulting in aneuploidy.

In vivo studies In vivo data gave varying results, largely depending on the route of exposure. The majority of reliable in vivo studies (Klimisch score 1 or 2) using physiological routes of exposure (inhalation or oral administration) were negative (see below). Some positive results following exposure via the inhalation route were reported, but these were in low reliability studies (Klimisch score 3) and were not further discussed in the RAC opinion.

• A bone marrow micronucleus assay (OECD TG 474) (Klimisch score 1) which gave negative results.

• A Comet assay (Klimisch score 1) that was negative for DNA damage and/or repair in the lung, but did report a concentration dependent increase in 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodGuo) DNA lesions with significant effects at 1 and 4 mg/m³. RAC noted that this increase was small in magnitude (2-fold).

• A bone marrow micronucleus assay (OECD TG 474) (Klimisch score 2) which gave negative results.

• An assessment of K-ras mutation in the development of lung tumours following exposure for up to 8 weeks (Klimisch score 2), which was negative

• A transgenic rodent somatic cell gene mutation assay (OECD TG 488) (Klimisch score 3 (DS)/2 (RAC)) which was negative


16

• A micronucleus assay in peripheral blood reticulocytes (Klimisch score 3) which was positive in males at all time points but negative in females

• An investigation of immunohistochemical changes in the actin of the testicular cytoskeleton (Klimisch score 3) showing microscopically observed structural DNA damage

• Observations of nuclear changes via electron microscopy of spleen cells from exposed mice (Klimisch score 3) which reported time-dependent nuclear changes in spleen lymphocytes.

• An analysis of morphological changes, liver function test (LFT), and oxidative stress damage in exposed mice (Klimisch score 3) which reported oxidative stress and an increase in the size of the nuclei of hepatocytes and binucleated cells.

• An evaluation of DNA migration in agarose gels (Klimisch score 3) which showed a significant increase in the length of DNA migration in liver, kidney, heart, lung, spleen and brain.

By contrast, studies using the i.p. route of administration gave positive responses. The following studies, all from the same laboratory were considered by RAC for the assessment of genotoxicity. These studies were the main evidence from the DS to support the change in the mutagenicity classification of vanadium pentoxide from category 2 to category 1B.

• A Comet assay in lung, kidney, spleen, heart, liver and bone marrow (Klimisch score 2) which gave positive results in all tissues with varying sensitivity. RAC queried the Klimisch score assigned by the DS given the limitations in the study.

• A negative bone marrow SCE assay (Klimisch score 2). RAC noted that this study is no longer relevant for the assessment of genotoxicity.

• A positive Comet assay in testicular cells (Klimisch score 2). RAC queried the Klimisch score assigned by the DS given the limitations in the study. It was also reported by RAC that the analysed testicular cells did not show any dose dependency for DNA damage.

• A positive dominant lethal test (Klimisch score 2) in which the number of resorptions was statistically significantly increased but the increase in the number of dead foetuses was not statistically significant. There was also a lower number of pregnant females and implantations. RAC noted the limitations in reporting the study conduct and results, which made it difficult to interpret. Consequently, RAC queried the Klimisch score assigned by the DS. RAC also considered that repeated i.p. administration was likely to result in high local levels of the substance in peritoneal cavity and testes and questioned the relevance of the study.

• A positive MN test in polychromatic erythrocytes (Klimisch score 3) which only gave a marginal but statistically significant increase at all time points. Numbers of apoptotic and necrotic cells were also reported to be increased.

RAC noted that further studies were available in the literature, but that these could not be independently evaluated as the study reports were not available. These were therefore not considered by RAC in its assessment. These studies included positive


17

MN tests via intraperitoneal, subcutaneous (s.c.) and inhalation exposure, a negative oral MN and DNA synthesis inhibition assay and negative dominant lethal test via s.c. administration. RAC also considered data on the toxicokinetics of vanadium after exposure to vanadium pentoxide which showed that vanadium reaches the testes. Increased vanadium levels were measured after oral administration of vanadium pentoxide (Klimisch score 1) and inhalation exposure ( Klimisch score 3). To support classification in category 1B, the DS used data on K-ras mutations in the two-year studies with vanadium pentoxide. In these studies , a high frequency of K-ras mutations and elevated phospho-MAPK were observed in vanadium pentoxide-induced alveolar/bronchiolar lung carcinomas. By contrast, K-ras mutations were not seen following inhalation exposure for up to 8-weeks, nor was there any evidence from a gene expression study (reported in the CLH report) showing enrichment of pathways associated with cell cycle arrest/proliferation, DNA damage or oxidative stress after 13 weeks inhalation exposure to 2 mg/m3 of vanadium pentoxide. Based on this data RAC concluded that the K- ras mutations seen in mice lung tumours likely occur at a later stage and were not an early event in vanadium pentoxide-induced mouse lung carcinogenesis.

Human data RAC also considered data from two research reports which evaluated genotoxicity in vanadium pentoxide exposed workers. In one study, no significant differences were reported between exposed and non-exposed test subjects for a comet assay or on 8-hydroxy-2' -deoxyguanosine (8-OHdG) or sister chromatid exchange (SCE). The second study reported increased numbers of micronuclei, nucleoplasmic bridges and nuclear buds in vanadium pentoxide factory workers when compared to the controls but there was no effect on DNA migration. A correlation between genotoxicity markers and plasma vanadium levels was not seen. Possible co-exposures to other impurities were also not discussed in the study. RAC found that no conclusions could be reached based on these studies. Conclusion on mutagenicity Overall RAC considered that modification of the existing classification for mutagenicity was not justified based on the available data. In summarising the data, RAC reported that: • Vanadium pentoxide did not appear to be directly mutagenic either in vitro or in

vivo. • Although exposure to vanadium pentoxide caused chromosomal effects in vitro,

negative results were obtained in well-conducted in vivo genotoxicity studies, using physiological routes of exposure.

• The positive findings in vivo were obtained largely from studies with an


18

unphysiological route of exposure, published by the same research group whose study design, analysis and reporting showed deficiencies and contradicted the data from other, high- quality studies.

RAC also noted the toxicokinetic data showing that vanadium can reach testes but did not consider this sufficient for a category 1B classification in the absence of any clear evidence of in vivo genotoxicity. Consequently, RAC recommended that the existing classification Muta. 2, H341 should be retained.

Classification proposed by the Agency: The Agency agrees with RAC’s assessment of the data. The Agency notes the minority opinion which considers that Muta 1B, as proposed by the DS, is justified. This was stated to be based on a weight-of-evidence assessment taking into account the positive in vitro micronucleus and comet assays, the positive mouse micronucleus study via the inhalation route supported by the positive results in studies via the i.p. route (a dominant lethal study, a MN study and two Comet assays), toxicokinetic data showing exposure of the testes to vanadium pentoxide and adverse effects in sperm cells after vanadium pentoxide exposure in repeated-dose inhalation studies. Taking the points raised into account, the Agency remains in agreement with RAC, considering them to have been fully addressed in the RAC opinion. Overall, the Agency considers that vanadium pentoxide does not meet the criteria for classification as Muta. 1B, and the existing classification as Muta 2; H341 (Suspected of causing genetic defects) should be retained.

Carcinogenicity

Classification agreed by RAC: Vanadium pentoxide is currently not classified for carcinogenicity. The DS proposed to classify vanadium pentoxide as carcinogenic category 1B based on the available data from studies in rats and mice. The RAC opinion concentrates on four of these studies. These were a two-year study (in rats and mice), a cancer promotion study and a one-year study in mice to support their conclusion. Additionally, human data and gene expression studies were reported in the CLH report. In a two-year study in rats, animals were exposed to vanadium pentoxide at 0.5, 1, or 2 mg/m3 via the inhalation route for six hours a day and 5 days per week. The total lung doses for each exposure group were estimated to be 130, 175, and 308 μg vanadium. There was no increase in tumours in females, while in males, slight increases in lung adenomas and carcinomas were seen when compared to


19

the control group. These findings showed no dose dependency. When compared to the limited historical control data (HCD), available at the time the study was conducted, only adenomas in the low dose group and carcinomas in the in low and high dose groups (but not in the mid-dose group) exceeded the historic controls. When compared to an extended data set (Starr et al, 2012) only the adenomas from the low dose group exceeded the HCD. Table 5. Summary of findings in the rat carcinogenicity study (table taken from RAC opinion – ECHA 2020)

Dose 0 mg/m3

0.5 mg/m3

1 mg/m3

2 mg/m3

HC*

Males

lung adenomas 4/50 8/49 5/48 6/50 0-12%

lung carcinomas 0/50 3/49 1/48 3/50 0-6%#

No of animals surviving to the end of the study

20 29 26 27

Mean survival (d)

668 680 692 671

BW No effect in exposed group compared to the controls

Females

lung adenomas 0/49 3/39 1/50 0/50 0-8% #

lung carcinomas 0/49 0/49 0/50 1/50 0-2%


33 24 29 30

Mean survival (d)

688 678 679 680

BW reduced at 2 mg/m3 when compared to the controls

*According to analysis by Starr et al. (2012) using data from animals fed with NTP-2000 diet. #In NTP report, only a limited number of HC data from animals fed with NTP-2000 diet were available and HC incidence was somewhat lower, for male lung carcinomas the range was 0%-2% and female lung adenomas it was 0%-6%.

There were no increases in tumours in any other organ. Chronic active inflammation and alveolar and bronchiolar epithelial hyperplasia were reported at all exposure concentrations, and at the top dose there was an increased incidence of interstitial fibrosis and alveolar/bronchiolar squamous metaplasia.


20

Overall, RAC concluded that the study in rats did not provide clear evidence on the carcinogenic potential of vanadium pentoxide at the dose levels causing inflammation and fibrosis in the lungs. In the study in mice (B6C3F1), animals were exposed to vanadium pentoxide at 1, 2 or 4 mg/m3 via the inhalation route for six hours a day and 5 days per week. The total lung doses for each exposure group were estimated as 153, 162, and 225 μg vanadium. Alveolar/bronchiolar carcinoma was significantly increased in both sexes at all dose levels and showed statistical significance in mid-dose males and in all dose groups in females, exceeding historical control ranges. Many animals had multiple adenomas and/or carcinomas. This finding of a clear increase in lung tumours was at dose levels causing lung inflammation and significant general toxicity (reduced survival, reduced mean body weights, abnormal breathing, significant increases in chronic inflammation, alveolar and bronchiolar hyperplasia and histiocytic cellular infiltrate (all doses) and increased interstitial fibrosis (2 or 4 mg/m3). Table 6: Summary of findings in the mouse carcinogenicity study (table taken form RAC opinion – ECHA 2020)

Dose 0 mg/ m3 1 mg/m3 2 mg/ m3 4 mg/m3 HC*

Males

lung adenomas

13/50 16/50 26/50 15/50 4-26%

lung carcinomas

12/50 29/50 30/50 25/50 4-24%


39 33 36 27

Mean survival (d)

710 692 704 668

BW reduced at 2 and 4 mg/m3 when compared to the controls

Females

lung adenomas

1/50 17/50 25/50 19/50 0-12%

lung carcinomas

0/50 23/50 18/50 22/50 0-6%


38 32 30 32

Mean survival (d)

692 655 653 688

BW reduced at all doses when compared to the controls *HC data from controls given NTP-2000 diet available at the time of the study.


21

A cancer promotion study in male mice (Klimisch score 2) suggested that vanadium pentoxide may have a tumour promotion activity, with a strain specific increase in lung tumours observed in A/J and BALB strains of mice but not C57BL/6J. This was associated with inflammation involving induction of multiple chemokines and transcription factors NFκB and c-Fos as well as activation of extracellular signal-regulated kinases 1 and 2. In a one-year study in mice, with limited reporting (Klimisch score 4), papillomatous and adenomatous tumours in the lungs were reported following exposure to vanadium pentoxide at 2 and 8 mg/m3. Conclusion on carcinogenicity RAC considered that the data from the two-year study in rats did not provide clear evidence of its carcinogenic potential. However, they agreed with the DS that the increased incidence of lung tumours seen at all doses in mice of both sexes could be attributed to exposure to vanadium pentoxide. Consequently, RAC concluded that the criteria for Category 1B were fulfilled. In reaching their conclusion, RAC noted the concerns expressed by the industry during the public consultation regarding the carcinogenicity study in rats and mice rats. Both studies were performed in accordance with GLP and while RAC noted that there were some limitations and concerns (particularly for dose selection), overall, they concluded that the study was a “generally well conducted study that was sufficient for classification purposes”. In their conclusion, RAC discussed some aspects of the data that may decrease the concern for humans at low exposure levels:

- High background tumour incidence in male mice: whilst a high background incidence could potentially decrease the level of concern, according to the NTP molecular oncology study, the tumours observed in mice showed a different mutational spectrum with a high frequency of K-ras mutations compared to the tumours observed in control animals. Also, a reduced tumour latency was observed in all exposed groups in mice (in controls, the first tumours were observed after 667-731 days, compared to 281-522 days in exposed mice).

- General toxicity and high incidence of inflammatory effects in the lungs of mice: RAC noted that inflammation may increase the risk for lung cancer by inducing oxidative stress and reactive oxygen species and secondary genotoxicity. Furthermore, G to T transformations in K-ras gene (as observed with vanadium pentoxide) have been considered as indicative for oxidative damage. Inflammation and secondary genotoxicity have been considered to play a role in metal-induced respiratory tract cancers; this mechanism may have an impact on the shape of the dose response and indicate the existence of a MoA-based threshold for the carcinogenic effects. Whilst this


22

may decrease the concern for cancer at low exposure levels, the tumours seen in the animal studies remain relevant for humans. In mice, a high incidence of malignant lung tumours was seen in both sexes starting from the lowest dose level. Inflammatory lesions were recorded in the majority of animals at the low dose, however they were primarily minimal to mild in severity. RAC considered that the flat dose-response seen in mice was likely related to the lung vanadium burdens, which were very close to each other in the different dose groups.

Overall, RAC agreed with the DS that vanadium pentoxide met the criteria for classification as carcinogenicity category 1B. RAC acknowledged that the main concern was related to the inhalation exposure, but considered that it was not possible to state the route of exposure as part of the classification. In doing so RAC noted the absence of systemic tumours in the inhalation studies in which systemic absorption was demonstrated but considered that induction of local tumours after oral exposure could not be excluded due to the lack of oral data. Consequently, the route of exposure was not specified. Classification proposed by the Agency: The Agency notes the uncertainties/limitations of the dataset and considers this to be a borderline case between Category 2 and Category 1B. Considering the weight of evidence, the Agency can support RAC’s conclusion that vanadium pentoxide meets the criteria for classification for carcinogenicity in Category 1B; H350 (May cause cancer) with no defined route of exposure.

Reproductive toxicity

Classification agreed by RAC: Vanadium pentoxide is currently classified in category 2 for reproductive toxicity with H361d. Under this assessment the DS proposed to modify the classification to include category 1B for effects on sexual function and fertility. In addition, classification for effects on/via lactation was proposed. Sexual function and fertility No generational reproductive toxicity studies were available for vanadium pentoxide. Instead RAC considered two 90-day repeat dose toxicity studies in rats and mice, and a number of research reports. These studies investigated the effects of vanadium pentoxide or other pentavalent vanadium compounds (eg ammonium and sodium metavanadates) on reproductive organs or fertility. In addition, a limited amount of human data was considered.


23

90-day repeat dose toxicity studies with vanadium pentoxide via the inhalation route Effects on reproductive organs and parameters were evaluated in rats and mice in guideline-based repeat dose toxicity (RDT) studies by the inhalation route. In these studies animals were exposed (whole body) to vanadium pentoxide at 0, 1, 2, 4, 8, or 16 mg/m3 for six hours a day and five days per week for 90-days. These studies were considered reliable (Klimisch score 1). No effects were seen in male rats up to the highest dose tested. In females, the oestrous cycle of animals exposed at 8 mg/m3 (but not to 16 mg/m3) was significantly longer compared to controls, and the number of cycling females in the 16 mg/m3 group was reduced. RAC considered 16 mg/m3 to be a toxic dose (3/10 animals died). In mice, male mice sperm motility was statistically significantly decreased at the top two doses but showed no clear dose response. A reduction in body weight was also observed. No effects on reproductive parameters were seen in female mice. Overall, RAC considered that a definitive conclusion on fertility could not be reached based on these studies, because of general toxicity, lack of consistency between the species and the lack of a dose response. In a third, low reliability study (Klimisch score 3), reported in the open literature, mice were exposed to vanadium pentoxide via the inhalation route to approximately 1.4 mg/m3 for one hour, twice a week for a total of 12 weeks. Microscopical evaluation found increased numbers of necrotic spermatogonium, spermatocytes and Sertoli cells were observed as well as pseudo-nuclear inclusion and disruption of cellular junctions in treated animals compared to controls. Vanadium levels in testes were increased. RAC noted that the same group had also published some immunohistochemical studies on the testicular toxicity of vanadium pentoxide. RAC noted that these contrasted with the high reliability studies above, which showed no effects on sperm parameters at significantly higher exposure levels. Studies with vanadium pentoxide via the intraperitoneal (i.p.) route Three studies were available to RAC, where rats, mice or guinea pigs were exposed to vanadium pentoxide via the i.p. route. This route of exposure was considered by RAC to limit their applicability to the assessment of reproductive toxicity, because it could result in high local concentrations of vanadium in the peritoneal cavity. Consequently, the studies were only used as supporting evidence. Two of the studies described decreases in sperm count and motility. One also reported decreases in implantation sites, live foetuses, and foetal weights and increased numbers of resorptions/dam and dead foetuses. Both studies were


24

considered reliable with restrictions by the DS (Klimisch score 2), however RAC was unclear of the basis for this given the deficiencies in the conduct and reporting of the studies (e.g. only one dose group and limited/contradictory/no information on general toxicity and route of exposure. In a third, low reliability study (Klimisch score 3) lower ovulation rates were reported in females dosed from birth to postnatal day 21. Studies with pentavalent vanadium compounds Owing to the limited data available on vanadium pentoxide, the DS proposed to read-across from reproductive toxicity data on other pentavalent vanadium compounds. This data included two reproductive toxicity studies in rats and a fertility study in male mice (not considered by the DS in the CLH proposal) via the oral route, and a reproductive/fertility study in rats via the i.p. route. All studies were considered of low reliability

In the first study rats were exposed to ammonium metavanadate at 200 ppm in drinking water (8.4 mg vanadium/kg bw/day) for 70 days. Significant sex weight reductions were observed in the testes, epididymis, prostate and seminal vesicles, together with reduced mating and fertility indices. These findings were seen in the absence of significant body weight reductions. In the second study in rats, animals were dosed with 5, 10, or 20 mg/kg bw/day of sodium metavanadate. Males were dosed for 60 days prior to mating while females were dosed for 14 days prior to mating and then either sacrificed ono gestation day 14 or postnatal day 21. No maternal effects were reported. Nor were there any significant adverse effects on the number of corpora lutea, implantations, live and dead foetuses or resorptions.

In the mouse study, animals were exposed to 20, 40, 60 or 80 mg/kg bw/day for 64 day. Findings included, decreases in the number of pregnant females relative to the controls but without a clear dose–response. No information was given on mating behaviour. There was no significant difference between the groups regarding the numbers of implantations, early or late resorptions, or dead or live fetuses. Decreased body weight was observed in the 80 mg/kg bw/d group. Epididymis weight was also reduced at this dose level, but testicular weights were not altered. Sperm counts were significantly decreased at 40, 60, and 80 mg/kg bw/d, but the sperm motility and morphology were unaffected. Histopathological examinations showed the testes were normal. The study via the i.p. route using sodium metavanadate up to 0.6 mg V/kg bw/d showed clear effects on the testis. Including, significantly reduced organ weights, reduced epididymal sperm count, increased percentage of abnormal sperm, reduction in serum testosterone levels and serum gonadotropins along with testicular lesions. However, RAC noted that i.p. administration may result in high local exposure to reproductive organs which is less relevant than for physiological routes of exposure.


25

Data from humans

Three studies in humans were available to RAC that investigated the association between sperm concentrations and vanadium levels. These studies provided contradictory results with one suggesting an association, while the other two showed no association between the vanadium content in seminal plasma and sperm concentration. Conclusion on Sexual function and fertility The data available to RAC on the effects of vanadium pentoxide exposure on sexual function and fertility were limited as there were no proper reproductive toxicity studies using an appropriate route of administration. Instead RAC based their conclusion on the available RDT studies with vanadium pentoxide supported by read-across from reproductive toxicity studies with ammonium and sodium metavanadates. RAC considered that the slight effects on reproductive parameters observed in the reliable inhalation RDT studies with vanadium pentoxide together with the results of the oral studies performed with ammonium and sodium metavanadates, raised a concern for effects on fertility. RAC did not agree with the DS that the data were sufficient for classification in category 1B because of limitations in the studies together with the contradictory findings. Overall, RAC concluded that vanadium pentoxide met the criteria for classification as Repr. 2 for effects on sexual function and fertility (H361f).

Development Vanadium pentoxide has an existing classification as category 2 for developmental toxicity. The DS proposed to retain this existing classification. RAC considered two developmental (teratogenicity) toxicity studies performed with vanadium pentoxide in mice that were reported in the published literature (both studies were given a low reliability score). The first of these reported significant reductions in foetal/litter weights, a change in the sex ratio, an increase in the number of abnormal foetus (short limbs), litters with abnormal foetuses and a reduced number of ossification centres in the forelimbs following exposure to 8.5 mg/kb bw/d via the i.p. route. In the second study, significant increases in the number of foetuses with less mature skeletons (no ossification of three of four elements: supraoccipital bone, sternum, metatarsalia, all caudal vertebrae) were observed in animals exposed to a single dose of 0.9 mg/kg bw vanadium pentoxide on gestation day 8. No effects were reported on resorption frequency, foetal weight, frequencies of foetal haemorrhages. Neither study reported any information on maternal toxicity.


26

In addition, RAC considered studies cited in earlier reviews, but for which full reports were not available. Delayed ossification was observed in rats orally exposed to vanadium pentoxide at 1 and 3 mg/kg bw/day, while at higher dose levels (9 and 18 mg/kg bw/day) skeletal abnormalities were significantly increased at doses causing significant decreases in body weight gain in dams (75% and 40% of control values). In studies in rats, which used i.p. dosing on different days of the organogenesis, reported developmental effects included embryo/foetal mortality and malformations, with some developmental effects (skeletal malformations, delayed ossification) reported in the absence of maternal toxicity. In the third study, an increased incidence of resorbed and dead foetuses at the two highest dose levels (0.56 and 2.25 mg/kg bw/day) and wavy ribs at the highest dose level were reported after the subcutaneous administration of vanadium pentoxide. No information on maternal toxicity was available for this study.

Since data specific for vanadium pentoxide was limited, the DS proposed a read-across approach from data generated with other pentavalent vanadium compounds (ammonium and sodium metavanadates). In rats, exposure to ammonium metavanadate via the oral route, produced increased foetalethality, reduced foetal birth weight and gross skeletal and visceral anomalies and reduced pup survival and viability indices, and decreased learning and memory responses in the absence of parental toxicity. Studies in rats with sodium metavanadate via the oral and i.p routes and mice via the i.p route similarly resulted in a developmental effects including increased incidences of embryo and foetalethality and visceral abnormalities and reduced foetal weights. In reviewing the available developmental toxicity data for both vanadium pentoxide and other metavanadates, RAC noted that all the studies had considerable limitations. These included exposure via the i.p. route, only one dose level tested, small numbers of pregnant animals/litters produced, inadequate data on the purity of the substance, or on maternal toxicity, or other limitations in the reporting. However, taking this into account RAC considered that the data suggested the potential to cause developmental effects following exposure to vanadium, and that in some cases these effects appear to occur in the absence of severe maternal toxicity.

Human data The dossier contained one epidemiological nested case control study which suggested an association between environmental vanadium exposure (measured by biomonitoring) and increased risk of low birth weight. RAC noted that vanadium exposure was measured once during pregnancy and may not be representative of the entire pregnancy. A supporting study by same research group is also provided. However, RAC reported that a contribution of other pollutants to the findings cannot be excluded and further studies are needed to show the causality of this observed association.


27

Conclusion on Developmental toxicity

Vanadium pentoxide has an existing classification as category 2 for developmental toxicity. The DS has proposed to retain this classification. There is limited data available on vanadium pentoxide and therefore the DS used read-across from data generated with ammonium and sodium metavanadates to support the proposal. RAC concluded that while all the available studies suffered from significant limitations in the conduct and reporting, the data supported each other and suggested developmental effects (foetal mortality, visceral and skeletal anomalies, developmental delays) in animal exposed to vanadium.

Overall, RAC concluded that the findings all pointed to vanadium pentoxide having the potential to cause developmental effects. Consequently, RAC concluded that classification as Repr 2 (suspected developmental toxicant, H361d) should be retained.

There are no human data available on either vanadium pentoxide or other vanadium compounds to address effects in infants following exposure from lactation. Nor are there any specific animal studies with vanadium pentoxide addressing effects via lactation. Consequently, the DS proposed a read-across approach from other pentavalent vanadates to reach a conclusion of effects via lactation. In addition, toxicokinetic data from studies with pentavalent vanadium compounds were used to support the conclusion.

Toxicokinetic studies RAC concluded that the available data, although considered of low reliability by the DS, were sufficient to provided evidence on the presence of vanadium in the mother’s milk and its uptake by pups. One toxicokinetic study, in which dams were exposed to radioactive pentavanadate, demonstrated the presence of elevated levels of vanadium in milk and tissue levels of suckling pups following exposure via the mother’s milk. A second study found elevated levels of vanadium in the livers of pups whose mothers had been fed on a diet containing sodium metavanadate. In addition RAC considered data from humans. This study reported that “lactating women secrete 17% of their vanadium intake into the milk”, based on lower levels excreted in the faeces and urine of lactating women compared to non-lactating woman. Studies with sodium and ammonium metavanadate Experimental data are available addressing effects following exposure via the milk with vanadium compounds such as sodium and ammonium metavanadate. RAC considered the read-across acceptable. Five studies performed with sodium metavanadate, in which the nursing dams (rats and mice) were exposed by i.p. injection to either ammonium or sodium metavanadate were summarised. While RAC agreed with comments regarding the


28

applicability of the i.p. route of exposure, they also agreed with the DS that, suckling pups were only exposed via lactation and therefore although these studies used i.p. administration they could be considered acceptable in the absence of studies using other routes of exposure There was no general toxicity reported in either dams or pups. However, the studies all reported deficits in the behavioural tests and showed damage to brain tissue/cells. Even when the limitations of the tests were taken into account the DS considered that the studies were sufficient to demonstrate an adverse effect of sodium metavanadate to the pup via lactation. The CLH report also referenced further studies with sodium metavanadate Further studies were referenced by the DS in the CLH report. These studies reported neurological effects in adult rodents or pups directly exposed to pentavalent vanadates and were considered by the DS as supporting evidence. They were not considered in the RAC opinion.

Comparison with the criteria- Lactation There is no specific data on vanadium pentoxide and therefore RAC based their assessment on data from other pentavalent vanadium compounds. There are toxicokinetic data in rodents showing excretion of vanadium to the milk and its uptake by the suckling pups resulting in higher tissue levels of vanadium when compared to the non-exposed pups. A number of studies reported suggested neurotoxic effects following exposure to vanadium via lactation. RAC noted that all the studies had limitations, however, when taken together with the toxicokinetic information considered they raised sufficient concern on possible lactation effects to warrant classification. Overall, RAC agreed with the DS that vanadium pentoxide meets the criteria for classification for lactational effects, H362: May cause harm to breast-fed children. Classification proposed by the Agency: Sexual function and fertility The Agency agrees with RAC’s assessment of the data. Vanadium pentoxide meets the criteria for classification for Repr. 2; H361f. Development The Agency agrees with RAC’s assessment of the data. Vanadium pentoxide meets the criteria for classification for Repr. 2; H361d. The classification should be retained. Effects on lactation The Agency agrees with RAC’s assessment of the data. Vanadium pentoxide meets the criteria for classification for Lactation; H362.


29

Aspiration hazard


Environmental hazards


Other hazards



30

Overall conclusion

The Agency has evaluated the RAC Opinion, its rationale and any additional scientific evidence that may have been made available to HSE against the criteria for classification and labelling in the GB CLP Regulation and technical guidance. The Agency technical report agrees with the classification proposed by RAC for the following hazards: Carc. 1B; H350 (May cause cancer) Muta. 2; H341 (Suspected of causing genetic defects) Repr. 2; H361fd (Suspected of damaging fertility. Suspected of damaging the unborn child) Lact.; H362 (May cause harm to breast-fed children) Acute Tox. 3; H301 (Toxic if swallowed) with an ATE of 220 mg/kg bw

Acute Tox. 2; H330 (Fatal if inhaled) with an ATE of 0.05 mg/l (dusts or mists) STOT RE 1; H372 (Causes damage to the respiratory tract through prolonged or repeated exposure via inhalation) The existing harmonised classification for STOT SE 3 and Aquatic Chronic 2 were not addressed in the CLH report or RAC opinion. As such, it has not been assessed in this technical report and should be retained in the entry. The Agency technical report disagrees with the classification proposed by RAC for the following hazards: Not applicable Overall, the conclusion is to agree with the RAC opinion.


31

References

ECHA (2017) Guidance on the application of the CLP criteria. Guidance to Regulation (EC) No 1272/2008 on classification, labelling and packaging (CLP) of substances and mixtures, version 5.0, ref: ECHA-17-G-21-EN. Available at https://www.echa.europa.eu/ For all other references, please see the EU CLH report and the EU RAC opinion (available at: https://echa.europa.eu/registry-of-clh-intentions-until-outcome) ECHA (2019) CLH report (including Annexes): Proposal for Harmonised Classification and Labelling Based on Regulation (EC) No 1272/2008 (CLP Regulation), Annex VI, Part 2. Substance Name: Divandium pentaoxide; Date: 2019; Accessed date: 07/2021 ECHA (2020) Committee for Risk Assessment (RAC) Opinion (including Annexes) proposing harmonised classification and labelling at EU level of divanadium pentaoxide; vanadium pentoxide; Reference CLH-O-0000006927-60-01/F; Date: 10/12/2020, Accessed date: 07/2021 Documents published as part of the EU CLH process: Source: European Chemicals Agency, http://echa.europa.eu/

https://echa.europa.eu/registry-of-clh-intentions-until-outcome


32

Glossary of terms used in Agency technical reports

Agency, the HSE, acting in its capacity as the GB CLP Agency AR Applied radiation ATE Acute toxicity estimate BCF Bioconcentration factor BOD Biological Oxygen Demand bw Body weight CAR Competent Authority Report CAS Chemical Abstracts Service CI Confidence interval CL Confidence limits CLH Harmonised Classification and Labelling

CLP Classification, labelling and packaging (of substances and mixtures) CO2 Carbon dioxide COD Chemical Oxygen Demand CV Coefficient of Variation d Day DAR Draft Assessment Report DOC Dissolved Organic Carbon DS Dossier Submitter DT Dissipation time OR degradation time (also DissT or DegT where

apparent) DT50 Dissipation half-life OR degradation half-life (hours or days), see

also above dw Dry weight

ECHA European Chemicals Agency ECx x% effect concentration

EFSA European Food Safety Authority ErCx x% effect concentration based on growth rate EU European Union GLP Good Laboratory Practice h Hours i.p. Intraperitoneal i.v. Intravenous KOC Organic carbon-water partition coefficient KOW Octanol-water partition coefficient LCx x% lethal effect concentration

MCL Mandatory Classification and Labelling M-factor Multiplying factor MN Micronucleus MW Molecular weight NOEC No-observed effect concentration NTP National Toxicology Program OECD Organisation for Economic Co-operation and Development


33

QSAR Quantitative structure-activity relationship

RAC Risk Assessment Committee RAR Renewal Assessment Report RCOM Response to comments document REACH Registration, Evaluation, Authorisation and Restriction of

Chemicals regulation s.c. Sub-cutaneous SCE Sister chromatid exchange STOT-RE Specific target organ toxicity – repeated exposure STOT-SE Specific target organ toxicity – single exposure TG Test Guideline US EPA United States Environmental Protection Agency wt Weight wwt Wet weight

Date post:	15-May-2023
Category:	Documents
Upload:	khangminh22
View:	0 times
Download:	0 times