Calcium acetylide

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:

weight of evidence

Study period:

1984

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

comparable to guideline study with acceptable restrictions

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1984

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Deviations:

yes

Remarks:

Only very low concentrations were tested due to technical difficulties. Only 3 strains tested. No cytotoxicty screening performed.

Principles of method if other than guideline:

The study's main objective was to develop a technique for testing appropriately air vapors in the Ames test. Toxicity and mutagenicity of styrene oxide were evaluated on log- and stationary-phase Salmonella TA100 cells, with the preincubation and plate incorporation method. As part of this research 12 different vapor-phase substances, including acetylene, were examined in this adapted Ames test.

GLP compliance:

not specified

Type of assay:

bacterial reverse mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

Acetylene

EC Number:

200-816-9

EC Name:

Acetylene

Cas Number:

74-86-2

Molecular formula:

C2H2

IUPAC Name:

acetylene

Test material form:

other: vapour

Details on test material:

Gas acetylene purchased from Matheson Scientific Company

Method

Species / strain

Species / strain / cell type:

S. typhimurium, other: TA97, TA98, and TA100

Additional strain / cell type characteristics:

not specified

Metabolic activation:

with and without

Metabolic activation system:

Rat liver S9 derived from Aroclor 1254 induced rats and hamsters

Test concentrations with justification for top dose:

0.30, 1.00, 3.00, 10.00, 31.00 μg/plate

Vehicle / solvent:

- Vehicle(s)/solvent(s) used: acetone

Controls

Untreated negative controls:

no

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

not specified

Details on test system and experimental conditions:

METHOD OF APPLICATION: preincubation with log-phase cells in full, not shaken vials

No cytotoxicity testing performed due to difficulties in preparing the right sample with acetylene.

DURATION
- Preincubation period: 48 h
- Exposure duration: 10 min
NUMBER OF REPLICATIONS: three

DETERMINATION OF CYTOTOXICITY
- Method: viability index

Evaluation criteria:

positive response: at least a two-fold increase in spontaneous revertants over background at two increasing dose levels

Results and discussion

Test results

Test results 1

Key result

Species / strain:

S. typhimurium TA 97

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

not determined

Remarks:

Due to technical difficulties: it is difficult to get high test concentrations of the gas acetylene in liquid suspension.

Vehicle controls validity:

valid

Untreated negative controls validity:

not examined

Positive controls validity:

valid

Test results 2

Key result

Species / strain:

S. typhimurium TA 98

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

not determined

Remarks:

Due to technical difficulties: it is difficult to get high test concentrations of the gas acetylene in liquid suspension.

Vehicle controls validity:

valid

Untreated negative controls validity:

not examined

Positive controls validity:

valid

Test results 3

Key result

Species / strain:

S. typhimurium TA 100

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

not determined

Remarks:

Due to technical difficulties: it is difficult to get high test concentrations of the gas acetylene in liquid suspension.

Vehicle controls validity:

valid

Untreated negative controls validity:

not examined

Positive controls validity:

valid

Test results 4

Key result

Species / strain:

S. typhimurium TA 102

Metabolic activation:

with and without

Genotoxicity:

not determined

Cytotoxicity / choice of top concentrations:

not determined

Vehicle controls validity:

not examined

Untreated negative controls validity:

not examined

True negative controls validity:

not examined

Positive controls validity:

not examined

Test results 5

Key result

Species / strain:

S. typhimurium TA 1535

Metabolic activation:

with and without

Genotoxicity:

not determined

Cytotoxicity / choice of top concentrations:

not determined

Vehicle controls validity:

not examined

Untreated negative controls validity:

not examined

True negative controls validity:

not examined

Positive controls validity:

not examined

Additional information on results:

Due to technical difficulties (getting high test concentrations of the gas acetylene in liquid suspension), acetylene was not tested for its toxic potential. The solubility of the gas in the test solvent limited the highest test concentration applied. The highest concentration applied was only 31 μg/plate. The raw data are presented in the attached pdf document.

Remarks on result:

other: all strains/cell types tested

Applicant's summary and conclusion

Conclusions:

Interpretation of results
negative

Acetylene did not induce any mutagenic effects on S.typhymurium strains TA97, TA98 and TA100, when tested under the conditions of this test, both with and without metabolic activation. However, due to technical difficulties for the generation of higher concentrations, concentration levels were only up to 31 μg/plate.

Executive summary:

The main objective of this study was to validate an appropriate method in order to test vapor-phase compounds in the Ames mutagenicity test. Several parameters were investigated and 12 vapor phase substances, including acetylene, were tested in the Ames test in order to validate the protocol. S. typhimurium strains TA97, TA98 and TA100 were exposed to acetylene, in acetoneat concentrations of 0.30, 1.00 , 3.00, 10.00 and 31.00 μg/plate in the presence and absence of mammalian metabolic activation (Aroclor-induced hamster and rat liver S9) in the pre-incubation method. The response was considered positive when at least a two-fold increase in spontaneous revertants over background at two increasing dose levels was detected.Acetylene could not be tested up to cytotoxic concentrations since no cytotoxicity screening was performed, due to difficulties of preparing the sample. Due to the difficulty of getting high test concentrations on the gas acetylene in liquid suspension, the highest concentration tested was only 31.00 μg/plate. The results revealed no mutagenicity response.The positive controls induced the appropriate responses in the corresponding strains.The authors of the study report suggested that additional experiments shall be peformed with some of the vapors, including acetylene, in order to be possible to test higher concentration levels.