Pivaloyl chloride

Genetic toxicity: in vitro

Administrative data

Endpoint:

in vitro gene mutation study in bacteria

Remarks:

Type of genotoxicity: gene mutation

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference 1

Reference Type:

study report

Title:

Unnamed

Year:

1999

Report date:

1999

Reference 2

Reference Type:

secondary source

Title:

SIDS Initial Assessment Report for SIAM 27 - Acid Chlorides (AC) Category

Author:

OECD SIDS

Year:

2008

Bibliographic source:

OECD SIDS

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

GLP compliance:

yes

Type of assay:

bacterial reverse mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

Pivaloyl chloride

EC Number:

221-921-6

EC Name:

Pivaloyl chloride

Cas Number:

3282-30-2

Molecular formula:

C5H9ClO

IUPAC Name:

2,2-dimethylpropanoyl chloride

Details on test material:

Purity: 99.6%

Method

Species / strain

Species / strain 1

Species / strain / cell type:

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

Species / strain 2

Species / strain / cell type:

E. coli WP2 uvr A

Metabolic activation:

with and without

Metabolic activation system:

liver S-9 supernatant of male Aroclor 1254 induced Sprague-Dawley rats

Test concentrations with justification for top dose:

experiment 1 (standard plate test; with and without S-9 mix;
all strains): 0, 20, 100, 500, 2500 and 5000 µg/plate;
experiment 2 (standard plate test; with and without S-9 mix;
all strains): 0, 125, 250, 500, 1000 and 1500 µg/plate;
experiment 3 (preincubation test, with and without S-9; all
strains): 0, 31.25, 62.5, 125, 250 and 500 µg/plate;
experiment 4 (preincubation test, with and without S-9;
TA100): 0, 100, 150, 200, 250 and 300 µg/plate.

Vehicle / solvent:

DMSO

Controls

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

Positive controls:

yes

Positive control substance:

other: see freetext

Details on test system and experimental conditions:

System: standard plate test, and preincubation test.
Preincubation of the test solution, bacterial suspension and S-9 mix at 37 °C for 20 minutes before being added to the soft agar.
Incubation: plates were incubated at 37 °C for 48-72 hours in the dark, then the number of colonies was counted.
Replicates: all tests were performed in triplicate.
Concentrations: the concentrations tested varied according to experiment:

Positive controls: N-methyl-N'-nitro-N-nitroso-guanidine (5µg/plate for strains TA100 and TA1535), 4-nitro-o-phenylenediamine (10 µg/plate, strain TA98), 9-aminoacridine (100 µg/plate for strain TA1537), and 2-aminoanthracene (2.5 µg/plate for all strains with S-9) were tested in each experiment. The positive control chemicals were dissolved in DMSO.

EXAMINATION
Precipitation of the test material was recorded (if present). Toxicity was detected by a decrease in the number of revertants, a clearing or diminution of the background lawn or a reduction in the titer.

EVALUATION
The experiment was considered valid if the number of colonies in the negative controls was within the normal range of the historical data for the strain, sterility controls had no evidence of contamination, the positive controls induced a significant increase in the number of revertants and the titer of viable bacteria was > = 10E9/ml.

Evaluation criteria:

A substance was considered mutagenic if it caused a doubling in the spontaneous mutation rate, in at least one strain, and the effect was dose-dependent and reproducible. A test substance was considered non-mutagenic if the number of revertants for all tester strains was within the historical
negative control range under all experimental conditions in 2 experiments carried out independently of each other.

Results and discussion

Test results

Test results 1

Species / strain:

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

Metabolic activation:

with and without

Genotoxicity:

positive

Remarks:

borderline result: weakly positve, result does not fit to other acid chlorides

Cytotoxicity / choice of top concentrations:

cytotoxicity

Remarks:

500-1000 µg/plate (standard plate); 250 µg/plate (preincubation)

Vehicle controls validity:

valid

Positive controls validity:

valid

Test results 2

Species / strain:

E. coli WP2 uvr A

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Remarks:

500-1000 µg/plate (standard plate); 250 µg/plate (preincubation)

Vehicle controls validity:

valid

Positive controls validity:

valid

Remarks on result:

other: strain/cell type: Preincubation test: S. typhimurium TA 100 without metabolic activation

Any other information on results incl. tables

Standard plate test: there was no mutagenic effect of the test material in any of the S. typhimurium or E. coli test strains, neither in the presence nor in the absence of metabolic activation.
Preincubation test: except S. typhimurium TA100, there was no mutagenic effect of test material in any of the S. typhimurium or E. coli test strains, neither in the presence nor in the absence of metabolic activation.
In TA 100, a slight increase in the number of revertants was seen in the absence of S-9, but not in the presence of S-9. The increase was dose-related and reached 1.5-fold (compared to vehicle control) at 250 µg/plate in the 3rd experiment., but decreased to 1.3-fold at 500 µg/plate. Therefore, a 4th experiment was conducted using TA100 w/wo S-9. Again, a dose-related increase was seen in the absence of metabolic activation. The control number of revertants was increased by a factor of 2.0 at 300 µg/plate. 

Although the substance showd an 2.0-fold increased in the spontaneous mutation rate in one strain (TA 100) at one concentration (300 µg/plate) in the preincubation test, this finding was not reproducible, as the increase was only 1.5fold at maximum in the other experiment at 250 mg/plate. Furthermore, the absolute numbers of the negative control (101 +/- 1) are rather low compared to the historical control range for this test and strain (PIT, TA 100, vehicle DMSO, no S-9 mix): mean +/- SD: 119 +/-16; min-max: 89-176. This increases the value relative to the control compared to the absolute numbers (201 +/- 10).

 

The test material did not precipitate. All positive controls induced at least a 5-fold increase in mutants. The weakly positive result does not fit with the results of other acid chlorides. Conclusion for acid chlorides on SIAM 27 was: " Bases on all the current available data, the acid chlorides are not expected to be genotoxic".