5-chlorovaleryl chloride

Endpoint summary

Key value for chemical safety assessment

Genetic toxicity in vitro

Description of key information

Ames (OECD471): negative (BASF, 1998)

Ames (OECD471): negative (only Strain TA1535) (BASF, 2022)

Link to relevant study records

Reference

Reference 1

Endpoint:

in vitro gene mutation study in bacteria

Remarks:

Type of genotoxicity: gene mutation

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1998

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

GLP compliance:

yes

Type of assay:

bacterial reverse mutation assay

Species / strain / cell type:

S. typhimurium TA 1535, TA 1537, TA 98 and TA 100

Additional strain / cell type characteristics:

not specified

Species / strain / cell type:

E. coli WP2 uvr A

Additional strain / cell type characteristics:

not specified

Metabolic activation:

with and without

Test concentrations with justification for top dose:

20 .0 ug - 5,000 ug/plate (SPT)
62 .5 ug - 1,000 ug/plate (PIT)

Vehicle / solvent:

Vehicle: DMSO

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

True negative controls:

not specified

Positive controls:

yes

Positive control substance:

other: 2-aminoanthracene for all strains

Remarks:

with S9 mix

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

True negative controls:

not specified

Positive controls:

yes

Positive control substance:

other: N-methyl-N'-nitro-N-nitroso-guanidine (MNNG) for TA100 and TA1535, 4-nitro-o-phenylendiamine for TA98, 9-aminoacridine for TA1537 and N-ethyl-N'-nitro-N-nitrosoguanidin (ENNG) for E.coli

Remarks:

without S9 mix

Details on test system and experimental conditions:

Preincubation test:
0 .1 ml test solution or vehicle, 0 .1 ml bacterial suspension and 0 .5 ml S-9 mix are incubated at 37°C for the duration of 20 minutes . Subsequently, 2 ml of soft agar is added and, after mixing, the samples are poured onto the agar plates within approx . 30 seconds. After incubation at 37°C for 48 - 72 hours in the dark, the bacterial colonies are counted .

Standard Plate test:
0 .1 ml of the overnight cultures is diluted to 10^-6 in each case . Test tubes containing 2 ml portions of soft agar containing maximal amino acid solution (5 mM tryptophan or 5 mM histidine + 0 .5 mM biotin) are kept a water bath at 45°C, and the remaining components are added in the following order :
0 .1 ml vehicle (without and with test substance)
0 .1 ml bacterial suspension (dilution : 10^-6 )
0 .5 ml S-9 mix

Species / strain:

S. typhimurium TA 1535, TA 1537, TA 98 and TA 100

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

other: A bacteriotoxic effect was observed from about 1,500 - 2,500 ug/plate onward (standard plate test) or at doses 2 500 μg/late (preincubations test)

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Species / strain:

E. coli WP2 uvr A

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

other: A bacteriotoxic effect was observed from about 1,500 - 2,500 ug/plate onward (standard plate test) or at doses 2 500 μg/late (preincubations test)

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Additional information on results:

No test substance precipitation was found .

Remarks on result:

other: all strains/cell types tested

Remarks:

Migrated from field 'Test system'.

Conclusions:

negative

Reference 2

Endpoint:

in vitro gene mutation study in bacteria

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Deviations:

yes

Remarks:

only one strain tested

GLP compliance:

yes (incl. QA statement)

Type of assay:

bacterial reverse mutation assay

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source (i.e. manufacturer or supplier) and lot/batch number of test material: 41049156P0

Species / strain / cell type:

S. typhimurium TA 1535

Metabolic activation:

with and without

Metabolic activation system:

Type and composition of metabolic activation system:
- source of S9 : male Wistar rats livers (phenobarbital i.p. and ß-naphthoflavone)

Test concentrations with justification for top dose:

0; 33; 100; 333; 1000; 2500 and 5000 μg/plate

Vehicle / solvent:

- Vehicle(s)/solvent(s) used: DMSO and acetonitrile

Negative solvent / vehicle controls:

yes

Positive controls:

yes

Positive control substance:

other: 2-aminoanthracene (2-AA); N-methyl-N'-nitro-N-nitrosoguanidine (MNNG)

Details on test system and experimental conditions:

Standard plate test
The experimental procedure of the standard plate test (plate incorporation method) was based on the method of Ames et al.
Salmonella typhimurium
Test tubes containing 2-mL portions of soft agar (overlay agar), which consists of 100 mL agar (0.8% [w/v] agar + 0.6% [w/v] NaCl) and 10 mL amino acid solution (minimal amino acid solution for the determination of mutants: 0.5 mM histidine + 0.5 mM biotin) were kept in a water bath at about 42 - 45°C, and the remaining components were added in the following order:
0.1 mL test solution, vehicle or positive control; 0.1 mL fresh bacterial culture; 0.5 mL S9 mix (with external metabolic activation) or 0.5 mL phosphate buffer (without external metabolic activation).
After mixing, the samples were poured onto Minimal glucose agar plates (Moltox Molecular Toxicology, Inc.; Boone, NC 28607; USA) within approx. 30 seconds.
After incubation at 37°C (mean value ±2°C) for 48 – 72 hours in the dark, the bacterial colonies (his+ revertants) were counted. The colonies were counted using the Sorcerer Image Analysis System with the software program Ames Study Manager (Perceptive Instruments Ltd., Haverhill, UK). In several cases, colonies were counted manually, in particular, if precipitation of the test substance hindered the counting using the Image Analysis System.

Preincubation Test
The experimental procedure was based on the method described by Yahagi et al. and Matsushima et al.
0.1 mL test solution, vehicle or positive control, 0.1 mL bacterial suspension and 0.5 mL S9 mix (with external metabolic activation) or phosphate buffer (without external metabolic activation) were incubated at 37°C for the duration of about 20 minutes using a shaker. Subsequently, 2 mL of soft agar was added and, after mixing, the samples were poured onto the agar plates within approx. 30 seconds.
After incubation at 37°C (mean value ±2°C) for 48 – 72 hours in the dark, the bacterial colonies were counted. The colonies were counted using the Sorcerer Image Analysis System with the software program Ames Study Manager (Perceptive Instruments Ltd., Haverhill, UK). In several cases, colonies were counted manually, in particular, if precipitation of the test substance hindered the counting using the Image Analysis System.

Species / strain:

S. typhimurium TA 1535

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Remarks:

a bacteriotoxic effect was observed at and above 2500 μg/plate under all test conditions using water free DMSO as vehicle and at 5000 μg/plate under all test conditions using acetonitrile

Vehicle controls validity:

valid

Positive controls validity:

valid

No precipitation of the test substance was observed with and without S9 mix.

A bacteriotoxic effect was observed at and above 2500 μg/plate under all test conditions using water free DMSO as vehicle and at 5000 μg/plate under all test conditions using acetonitrile

Conclusions:

Under the experimental conditions chosen here, it is concluded that 5-Chlorovaleryl chloride is not a mutagenic test substance in the bacterial reverse mutation test in the absence and the presence of external metabolic activation.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (negative)

Genetic toxicity in vivo

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

Genetic toxicity in vitro:

The substance 5-chloropentanoyl chloride was tested for its mutagenic potential based on the ability to induce back mutations in selected loci of several bacterial strains in the Ames test and in the Escherichia coli - reverse mutation assay. Strains tested TA 1535, TA 100, TA 1537, TA 98 and E. coli WP2 uvrA at doses of 20.0 ug - 5,000 ug/plate (SPT), and 62.5 ug - 1,000 ug/plate (PIT) in DMSO. Standard plate test (SPT) and preincubation test (PIT) both with and without metabolic activation (Aroclor induced rat liver S-9 mix). No precipitation of the test substance was found. A bacteriotoxic effect was observed from about 1,500 - 2,500 ug/plate onward (SPT) or at doses of 500 ug/plate (PIT). An increase in the number of his' or trp` revertants was not observed both in the standard plate test and in the preincubation test either without S-9 mix or after the addition of a metabolizing system. According to the results of the present study, the test substance 5-chloropentanoyl chloride is not mutagenic in the Ames test and in the Escherichia coli - reverse mutation assay under the experimental conditions chosen here (1998, RL1).

Further information:

In another OECD471 study, no signs of toxicity were observed up to 5000 μg/plate 5-chlorovaleryl chloride in acetonitrile. But concentration-related increases in revertant colony numbers were obtained with strain TA1535 at the two highest concentrations 5-chlorovaleryl chloride in both the absence and presence of S9 mix. Thus, 5-chlorovaleryl chloride was concluded to exhibited mutagenic activity in the bacterial system under these test conditions (unpublished report, 2006). 

However, the test substance 5-chlorovaleryl chloride was tested for its mutagenic potential based on the ability to induce point mutations in selected loci of the Salmonella typhimurium strain TA 1535 in a reverse mutation assay. The strain TA 1535 was tested at doses of 33 μg - 5000 μg/plate (SPT and PIT). Standard plate test (SPT) and preincubation test (PIT) both with and without external metabolic activation (liver S9 mix from rats treated with enzyme inducers). No precipitation of the test substance was observed with and without S9 mix. A bacteriotoxic effect was observed at and above 2500 μg/plate under all test conditions using water free DMSO as vehicle and at 5000 μg/plate under all test conditions using acetonitrile. A relevant increase in the number of his+ (increased by a factor of 3 or above for Salmonella typhimurium TA 1535) was not observed in the standard plate test or in the preincubation test with or without the addition of an external metabolizing system. Under the experimental conditions of this study, the test substance 5-chlorovaleryl chloride is not mutagenic in the Salmonella typhimurium reverse mutation assay with TA 1535 in the absence and presence of external metabolic activation (2022, RL1).

Overall conclusion:

In the key study no mutagenicity, but cytotoxicity at the highest concentrations was observed in the bacterial reverse mutation assay. This was also observed in the most recent study in 2022. However, increasing numbers of revertants of a single strain (TA1535) with and without metabolic activation were observed at the highest concentrations in another Ames test. This might be explained by interlaboratory variation, including the use of test substances from different sources. Supportingly to the observed negative results, the hydrolysis product 5-chloro valeric acid, which would rapidly be formed and be present in the in vitro and vivo situation, is also described to be negative in the Ames test (JETOC, 1985). Therefore, 5-chloro valeryl chloride is considered to be negative for in vitro mutagenicity.

Concerning the risk assessment, further tests – neither for in vitro nor in vivo mutagenicity – are not necessary as the substance is registered as a transported isolated intermediate.

Justification for classification or non-classification

Based on the information available for 5-chloropentanoyl chloride, classification for genetic toxicity is not warranted in accordance with EU Classification, Labeling and Packaging of Substances and Mixtures (CLP) Regulation No. 1272/2008.