butyl(triphenyl)phosphonium bromide

Endpoint summary

Key value for chemical safety assessment

Genetic toxicity in vitro

Description of key information

Negative in reverse gene mutation assay in bacteria (Salmonella typhimurium TA 98, TA 100, TA 1535, TA 1537 and TA 102 and Escherichia coli WP2uvrA, with and without metabolic activation (OECD 471/EU B.13/14, GLP, read-across from structural analogues)

Link to relevant study records

Reference

Endpoint:

in vitro gene mutation study in bacteria

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Justification for type of information:

REPORTING FORMAT FOR THE ANALOGUE APPROACH

1. HYPOTHESIS FOR THE ANALOGUE APPROACH
This read-across is based on the hypothesis that source substances and target substance have similar genetic toxicity because they share structural similarities with common functional groups. Source as well as target substances are all alkyltriphenylphosphonium halogen salts. The alkyltriphenylphosphonium moiety of source substances and target is almost identical, differing only in the length of the saturated linear alkyl chain (ethyl instead of n-butyl). The counterion of source 1 and target is identical - bromide, while source substance 2 has iodide as counterion.

2. SOURCE AND TARGET CHEMICAL(S) (INCLUDING INFORMATION ON PURITY AND IMPURITIES)

Source 1 Target
Name Ethyltriphenylfosfonium bromide n-Butyltriphenylphosphonium bromide
CAS 1530-32-1 1779-51-7
EC 216-223-3 217-219-4
Common functional group 1 counterion bromide counterion bromide
Common functional group 2 Triphenylphosphonium Triphenylphosphonium
Deviating functional group alkyl chain ethyl alkyl chain n-butyl
Purity Please refer to section ´Confidential details in general comparable to source substance
on test material´ of the respective source substance ID.

Source 2 Target
Name Ethyltriphenylphosphonium iodide n-Butyltriphenylphosphonium bromide
CAS 4736-60-1 1779-51-7
EC 225-245-2 217-219-4
Common functional group Triphenylphosphonium Triphenylphosphonium
Deviating functional group 1 saturated aliphatic chain ethyl saturated aliphatic chain n-butyl
Deviating functional group alkyl chain ethyl alkyl chain n-butyl
Purity Please refer to section ´Confidential details in general comparable to source substance
on test material´ of the respective source substance ID.

3. ANALOGUE APPROACH JUSTIFICATION
Read-across data used. The read-across hypothesis is based on the assumption that source substances and target do have comparable genetic toxicity. Source substances and target are all alkyltriphenylphosphonium halogen salts with an almost identical organic moiety, Ethyltriphenylphosphonium ion instead of n-Butyltriphenylphosphonium ion. Source 1 and target do have bromide as counterion, whereas source substance 2 has iodide as counterion.
However, all substances are soluble in water and also expected to be in physiological liquids. When dissolved, the organic moiety and the counterions act individually. Ethyltriphenylphosphonium iodide and - bromide were both negative in the bacterial reverse mutation assay, demonstrating that the counterions bromide and iodide of Alkyltriphenylphosphonium salts are not mutagenic. As the organic moiety of n-Butyltriphenylphosphonium differs from both source substances only in the length of the saturated alkyl chain - n-butyl instead of ethyl - and saturated alkyl chains are also not associated with genetic toxicity, this read-across is justified.
Both source entries are filled in as key studies as in addition to Salmonella typhimurium TA 98, TA 100, TA 1535 and TA 1537 source substance 1 was tested in E. coli WP2 uvr A and source substance 2 in Salmonella typhiumurium TA102.

Reason / purpose for cross-reference:

read-across source

Reason / purpose for cross-reference:

read-across source

Key result

Species / strain:

other: all strains tested: S. typhimurium TA 98, 100, 102, 1535 and 1537 and E. coli WP2 uvr A

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Remarks:

toxicity (reduction of the bacterial background lawn)

Vehicle controls validity:

valid

Positive controls validity:

valid

Conclusions:

Negative all strains tested: S. typhimurium TA 98, 100, 102, 1535 and 1537 and E. coli WP2 uvr A, with and without metabolic activation.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (negative)

Genetic toxicity in vivo

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

Read-across data used. The read-across hypothesis is based on the assumption that source substances and target do have comparable genetic toxicity. Source substances and target are all alkyltriphenylphosphonium halogen salts with an almost identical organic moiety, Ethyltriphenylphosphonium ion instead of n-Butyltriphenylphosphonium ion. Source 1 and target do have bromide as counterion, whereas source substance 2 has iodide as counterion. However, all substances are soluble in water and also expected to be in physiological liquids. When dissolved, the organic moiety and the counterions act individually. Ethyltriphenylphosphonium iodide and - bromide were both negative in the bacterial reverse mutation assay, demonstrating that the counterions bromide and iodide of Alkyltriphenylphosphonium salts are not mutagenic. As the organic moiety of n-Butyltriphenylphosphonium differs from both source substances only in the length of the saturated alkyl chain - n-butyl instead of ethyl - and saturated alkyl chains are also not associated with genetic toxicity, this read-across is justified.

In in vitro bacterial reverse mutation assays according to OECD guideline 471 and EU method B.13/14, source substances Ethyltriphenylphosphonium iodide and Ethyltriphenylfosfonium bromide revealed no genetic toxicity. Because of this results, n-Butyltriphenylphosphonium bromide in all probability has also no genotoxic activity.

Justification for classification or non-classification

In in vitro bacterial reverse mutation assays according to OECD guideline 471 and EU method B.13/14, Ethyltriphenylphosphonium iodide and Ethyltriphenylfosfonium bromide revealed no genetic toxicity.

As the organic moieties of n-Butyltriphenylphosphonium bromide and Ethyltriphenylphosphonium iodide and Ethyltriphenylfosfonium bromide differ only in the length of the saturated alkyl chain - n-butyl instead of ethyl - and saturated alkyl chains are not associated with genetic toxicity as well as the counterions bromide and iodide, n-Butyltriphenylphosphonium bromide in all probability has also no genotoxic activity.

According to the criteria of REGULATION (EC) No 1272/2008, n-Butyltriphenylphosphonium bromide does not have to be classified and has no obligatory labeling requirement for mutagenicity. According to the Globally Harmonized System of Classification and Labeling of Chemicals (GHS) of the United Nations (2004), n-Butyltriphenylphosphonium bromide does not have to be classified for mutagenicity.