Silver bromide

Endpoint summary

Description of key information

Silver compounds are not a sensitizer for skin

Key value for chemical safety assessment

Skin sensitisation

Link to relevant study records

Reference

Endpoint:

skin sensitisation: in vivo (non-LLNA)

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1995-09-12 trough 1995-10-06

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 406 (Skin Sensitisation)

Qualifier:

equivalent or similar to guideline

Guideline:

EU Method B.6 (Skin Sensitisation)

GLP compliance:

yes

Type of study:

not specified

Justification for non-LLNA method:

The study was performed before the LLNA method was the first choice method for this endpoint

Species:

guinea pig

Details on study design:

Ten test and six control albino guinea pigs were used. The intradermal induction of the test substance was applied by 0.1 ml injection of a 10% dilution. The topical induction, one week later, was performed by application of patches loaded with undiluted test substance (test site pretreated with sodium lauryl sulphate) for 48 hours. The challenge treatment (24 hours), 14 days after the last induction, consisted of patches loaded with undiluted test substance as well.

Reading:

1st reading

Hours after challenge:

24

Group:

test chemical

Dose level:

100%

No. with + reactions:

0

Total no. in group:

10

Clinical observations:

No skin reactions were observed in test or control animals following the challenge application in the main study after 24 hours.

Remarks on result:

no indication of skin sensitisation

Reading:

1st reading

Hours after challenge:

24

Group:

negative control

Dose level:

100%

No. with + reactions:

0

Total no. in group:

10

Clinical observations:

No skin reactions were observed in test or control animals following the challenge application in the main study after 24 hours.

Remarks on result:

no indication of skin sensitisation

Group:

positive control

Remarks on result:

not measured/tested

Range finding for intradermal induction: Three animals were intradermal treated with 100%, 30%, 10% and 3% concentrations of the test substance. Scores were obtained 24 hours after application. Slight to moderate irritation was observed in all concentrations tested. From the 30% concentration upward necrosis was observed as well. No irritation was observed after topical induction with 30% and 100% test substance concentrations in three animals. Challenge: No skin reactions were observed in test or control animals following the challenge application in the main study after 24 hours.

Interpretation of results:

GHS criteria not met

Conclusions:

On the basis of the results obtained it was concluded that, under the conditions of this study and according to the EC-standards silver thiosulphate is not a sensitizer.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not sensitising)

Additional information:

in-vivo data:

Two reliable studies on standard skin sensitisation tests are available with silver containing products/preparations:

• Prinsen, M.K. (1995): Sensitization study in guinea pigs (maximization test) with a liquid plant preservative preparation containing 18 g/L of silver thiosulfate in aqueous solution, besides other ingredients.


• Moore, G.E. (1999): Dermal sensitisation study (Buehler Method) in guinea pigs, with a biocidal product (aqueous solution) containing 2438 ppm Ag+ ions, besides other ingredients.

In addition, long term industrial experience does not raise any concern on skin sensitisation attributable to silver substances (personal communication, members of the Silver Work Group of the Precious Metals and Rhenium Consortium, 2010-07-27). Furthermore, a literature search has been conducted to check whether published literature is available which would provide further information on the potential occurrence or absence of skin sensitisation effects of silver substances, specifically in occupational settings. A report on this literature search is attached to the endpoint summary on sensitisation in the technical dossier. As a result, only a limited number of case reports dealing with skin sensitisation could initially be identified. However, upon close inspection, in several of these silver was not the potential cause. For example, one study investigated skin effects in workers with a range of precious metal compounds and found that silver compounds were not causing allergic skin reactions (Bruevich et al 1980). In other cases, “silver” was mentioned but not in the context of sensitisation by silver, but e. g. where thiourea contained in a silver polish was identified as a sensitiser (Dooms-Goossens, 1988).

Overall, very few publications are available and no specific concern for sensitising properties of silver (compounds) could be identified based on human data.

 

Conclusion:

Neither human nor animal data show any specific concern for skin sensitising properties of silver substances. In a read-across approach, it is concluded that classification for skin sensitisation is not required and that further experimental verification is not justified.

Respiratory sensitisation

Endpoint conclusion

Endpoint conclusion:

no study available

Justification for classification or non-classification

Neither human nor animal data show any specific concern for skin sensitising properties of silver substances. In a read-across approach, it is concluded that classification for skin sensitisation is not required and that further experimental verification is not justified.

Similarly, based on a complete absence of any indication of respiratory sensitisation in the public domain, classification is not required.