Calcium iodate

Endpoint summary

Key value for chemical safety assessment

Genetic toxicity in vitro

Description of key information

Calcium Iodate was found to be non genotoxic.

Link to relevant study records

Reference

Endpoint:

in vitro DNA damage and/or repair study

Remarks:

Type of genotoxicity: DNA damage and/or repair

Type of information:

migrated information: read-across based on grouping of substances (category approach)

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Qualifier:

according to guideline

Guideline:

other:

Principles of method if other than guideline:

Cells were exposed for 3 h to concentrations of the test compounds of 0.625, 1.25, 2.5, 5 and 10 mM. Tests compound was dissolved in the culture medium. Etoposide (0.5 µg/ ml) was dissolved in DMSO.
After cells exposure to the test compounds for 3 h, the culture medium was discarded and replaced by fresh medium. Cells were incubated for 0.5, 1 or 24 h and DNA damage was measured at each sampling time by the alkaline comet assay.

GLP compliance:

not specified

Type of assay:

comet assay

Target gene:

no data

Species / strain / cell type:

Chinese hamster Ovary (CHO)

Details on mammalian cell type (if applicable):

Chinese hamster ovary (CHO-K1) cells were purchased from Eurobio (France). They were routinely maintained from stocks stored in liquid nitrogen. CHO cells were grown at 37 C in a humidified atmosphere at 5% CO2 in air, in HAM’S F12 medium with l-glutamine supplemented with 10% fetal calf serum (FCS), penicillin (50 UI/ml) and streptomycine (50 µg/ml). Cells were subcultured 24 h before treatment.

Additional strain / cell type characteristics:

not specified

Metabolic activation:

not specified

Test concentrations with justification for top dose:

0.625, 1.25, 2.5, 5 and 10 mM

Vehicle / solvent:

culture medium

Untreated negative controls:

yes

Negative solvent / vehicle controls:

not specified

True negative controls:

not specified

Positive controls:

yes

Positive control substance:

other: Etoposide (0.5 µg/ml)

Species / strain:

Chinese hamster Ovary (CHO)

Metabolic activation:

not specified

Genotoxicity:

negative

Remarks:

The results showed that the comet assay failed to detect the presence of DNA damage after a treatment of cells by potassium iodate for concentrations up to 10 mM.

Cytotoxicity / choice of top concentrations:

not specified

Vehicle controls validity:

not specified

Untreated negative controls validity:

valid

Positive controls validity:

valid

Remarks on result:

other: strain/cell type: Chinese hamster ovary (CHO-K1) cells

Remarks:

Migrated from field 'Test system'.

Conclusions:

Interpretation of results (migrated information):
negative

Potassium iodate did not induce DNA damage in CHO cells when tested at concentrations up to 10 mM in alkaline comet assay.

Executive summary:

Potassium iodate did not induce DNA damage in CHO cells when tested at concentrations up to 10 mM in alkaline comet assay.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (negative)

Additional information

Additional information from genetic toxicity in vitro:

Genetic toxicity :

Based on the various studies available with Klimish rating 4 for read across substances considering weight of evidence approach.

The results is summarized as follows

 

Sr. No	End point	Effect	Species	Remarks
1	DNA damage and repair	negative	Chinese hamster Ovary (CHO)	Data is from publication for CAS NO 7758-05-6
2	chromosome aberration	negative	chinese hamster Ovary (CHO)	Data is from publication for CAS NO 7758-05-6
3	Gene mutation	negative	mouse lymphoma L5178Y cells   Mammalian cell line Balb/c 3T3 cells	Data is from publication for CAS NO 7681-11-0
4	Radiation-sensitizing effects on DNA	negative	Marbourg strains of Bacillus subtilis	Data is from publication for CAS NO 7681-11-0

 

By applying weight of evidence approach to the studies summarized in the above table it can be concluded that the substanceCalcium iodate is not likely to exhibit positive genetic toxicity effect. Thus calcium iodate is considered to be non-mutagenic substance as per the CLP criteria.

 

 

Justification for selection of genetic toxicity endpoint
Potassium iodate did not induce DNA damage in CHO cells when tested at concentrations up to 10 mM in alkaline comet assay.

Justification for classification or non-classification

From the results obtained for calcium iodate it can be concluded that the substance Calcium iodate is not likely to exhibit positive genetic toxicity effect