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Administrative data

Key value for chemical safety assessment

Additional information

The substance has no structural alerts for mutagenicity, and a large database of performed studies indicate that p-TSA does not have genotoxic properties. Most of the available studies showed negative responses, and only incidentally a questionable or marginally positive result was obtained at highest cytotoxic level. The table below lists all available data, including from literature.

Test System or Species, Strain, Age, Number, and Sex of Animals

Biological Endpoint

S9

Chemical Form and Purity

Dose

Results/Comments

Reference

Prokaryotic Systems

S. typhimurium strainsTA98, TA100, TA1535, TA1537, TA1538;Saccharomyces cerevisiaeD4

Increase in revertants due to mutations

+/-

p-TSA in DMSO

1, 10, 100, 500, 1000 µg/plate

No mutagenic effects observed. Highest dose 1000 µg/plate was based on toxicity pre-test, Highest dose is selected to show slight toxicity.

Proprietary

Litton Bionetics, 1978

S. typhimurium strainsTA98, TA100, TA1535, TA1537;Escherichia coliWP2 uvrA

Increase in revertants due to mutations

+/-

p-TSA in DMSO; purity 99.9%

0, 312.5, 625, 1250, 2500, 5000 μg/plate

No mutagenic effects observed under the test conditions. Minimum toxic concentration observed for bacteria was 5000 μg/ with and without activation.

MHW, Japan; cited by OECD (1994)

S. typhimurium strainsTA98, TA100, TA102

Increase in revertants due to mutations

+/-

p-TSA in acetone

TA98 &100: 0, 33, 100, 333, 1000 and 2000 or 3333 µg/plate; TA102: 0, 100, 333, 1000, 3333 and 10000 µg/plate

No mutagenic effects observed under the test conditions.

Report available onhttp: //tools. niehs. nih. gov/ntp_tox

NTP, 2007

S. typhimurium strainsTA1530, TA1535, TA1538, TA98, and TA100

Increase in revertants due to mutations

+

p-TSA in DMSO Purest grade commercially available

4 x 10-7 mol up to 4 x 10-2 mol/plate.

Plate incorporation tests were performed in triplicate, mixing dilutions of test material (0.1 mL) with bacterial cultures (1 – 8 x107 cells) with broth and S9 mix. No direct mutagenic effects were observed. p-TSA was cytotoxic to TA1538 and TA98.

Poncelet et al. (1980)

S. typhimuriumstrainsTA98, TA100, TA1535, TA1537

Increase in revertants due to mutations

+/-

p-TSA in DMSO

Up to 18000 μg/plate

No mutagenic activity was observed. Evaluations included testing in ZLM agar (similar condition Eckhardt, 1981)

Herbold (1981)

S. typhimurium –TA98, TA100, TA1535, TA1537 and TA1538.

Increase in revertants due to mutations

+/-

p-TSA

Doses of up to 12 mg/plate were used.

The only positive (marginally) increase in revertants were found intester strain TA98, with S9 and only using ZLM agar, and not in VB agar.

Eckhardt et al. (1980)

Lower Eukaryotic Systems

D. melanogaster(Berlin K [wild-type] and Basc strains)

SLRL (Sex-linked recessive lethal) test

na

p-TSA

Conc. 2.5 mM in 5% sucrose solutions used as feed for 3 days.

A small but statistically significant increase in the frequency of recessive lethal mutations was observed only in the first brood, corresponding to mature sperm. (about double the control frequency)

Eckhardt et al. (1980)

D. melanogaster(Oregon-K [wild type] and Basc strains)

SLRL (Sex- linked recessive lethal) test

na

p-TSA

Adult flies injected abdominal with about 0.2 μL of a 5 mM solution (~0.170 μg)

There were no or marginal positive effects observed in first brood under the test conditions. (frequency was about 2.5 times higher than of the control)

Kramers (1977)

Mammalian SystemsIn Vitro

L5 178Y mouse lymphoma cells

forward mutations (TK locus)

+/-

p-TSA in DMSO, purity 99.9%

Up to 5000 µg/mL

An increased frequency of mutations was only observed at the highest, cytotoxic, dose level with metabolic activation, involving an increase in small colonies.

Proprietary.

Covance, 2000

CHL cells

Chromosomal aberration

+/-

p-TSA in DMSO, purity 99.9%

Without S9: 0, 0.33, 0.65, 1.30 mg/mL; with S9: 0, 0.43, 0.85, 1.70 mg/mL.

The test material was classified as “negative” for chromosomal aberrations, under the test conditions. The lowest concentration producing cell toxicity was >2.0 mg/mL [11.68 mM] with metabolic activation and 2.0 mg/mL without metabolic activation.

MHW, Japan; cited by OECD (1994)

CHO-K1 cells

Chromosomal aberration

-

p-TSA, purity n. p.

Cells were treated with 14, 200, and 400 μg/mLp-TSA for 24 h.

Untreated cells were used as a negative control; sodium saccharine treated cells were the positive controls. There was no significant difference in the frequency of aberrant cells between treatment groups and controls. The sodium saccharine gave a positive response.

Masubuchi (1978a abstr)

RSa human cell line

Development of ouabain resistance

-

p-TSA in sterile water for injection.

900 and 1800 μg/mL [5.26 and 10.51 mM], for 24 h

8x10^5 cells were treated top-TSAin serum-free medium for 24 h. Cells were allowed 48 h for mutant expression. The fraction of mutant cells was assayed by seeding 5X10^4 cells/100-mm culture dish (6 replicates) in ouabain-containing medium. Plating efficiency was also determined. Mutant frequency was calculated and expressed as mutants/10^5 colony-forming cells. No increase in ouabain resistance was observed inp-TSAtreated cells, relative to controls.

Suzuki and Suzuki (1988)

Mammalian SystemsIn Vivo

Mouse Crl: CD-1, adult, M and F

MN

induction

na

p-TSA in corn oil, purity 99.3%

Oral 187.5, 375, 750, 1500 mg/kg bw

Does not increase frequency in micronuclei in mouse bone marrow PCE.

Number of animals: 24 hrs, all doses 6/group/sex; 48 hr high dose & control 6/animals/group/sex

Proprietary.

Covance, 2002

Mouse Crl: CD-1, adult, only males

MN

induction

na

p-TSA 

i. v. 80, 120, 160 mg/kg bw,

Does not increase frequency in micronuclei in mouse bone marrow PCE.

Number of animals: 24 hrs, all doses 6/group; 48 hr high dose & control 6/animals/group

Proprietary.

Covance, 2000

Mouse, NMRI, adult,

number n. p., M and F

MN

induction

na

p-TSA in 3% Arabic gum.

p-TSA administered both orally 2 x 855 mg/kg and i. p. 2 x 428 and 2 x 855 mg/kg

There were no effects observed under the test conditions.

Eckhardt et al. (1980)

np = not provided; na = not applicable

 

References:

·  Covance, 2000, Proprietary: in vitro-Mouse Lymphoma, report# 21198-0-431-ICH

·  Covance, 2000, Proprietary: in vivo-micronucleus, report# 21198-0-455OECD

·  Covance, 2002, Proprietary: in vivo-micronucleus, report# 3464-0-455OECD

·  Eckhardt K., M.T. King, E. Gocke, and D. Wild. 1980. Mutagenicity study of Remsen-Fahlberg saccharin and contaminants. Toxicol Lett 7:51-60

·  Herbold B.A. 1981 . Studies to evaluate artificial sweeteners, especially Remsen-Fahlberg saccharin, and their possible impurities, for potential mutagenicity by the Salmonella mammalian liver microsome test. Mutat Res 90:365-372.

·  Kramers P.G. 1977. Mutagenicity of saccharin in Drosophila: The possible role of contaminants. Mutat Res 56:163-167

·  Litton Bionetics, 1978, Proprietary: in vitro-Ames, report# 20838

·  Masubuchi, M., S. Nawai, M. Hirokado, and K. Hiraga. 1978a abstr. Lack of the cytogenetic effects of saccharin impurities on CHO-K1 cells. Mutat. Res. 54[2], 242-243.

·  MHW, Japan; cited by OECD (1994) – Ames: Hatano Research Institute, Food and Drug Safety Center, Japan, Reverse Mutation Test of 4 -Methylbenzenesulfonamide on Bacteria (http://dra4.nihs.go.jp/mhlw_data/home/pdf/PDF70-55-3e.pdf)

·  MHW, Japan; cited by OECD (1994) – CHL: Hatano Research Institute, Food and Drug Safety Center, Japan, In vitro Chromosomal Aberration Test of 4-Methylbenzenesulfonamide on Cultured Chinese Hamster Cells (http://dra4.nihs.go.jp/mhlw_data/home/pdf/PDF70-55-3f.pdf)

·  NTP, 2007: The Salmonella Mutagenicity Test on p-Toluenesulfonamide, report A84238 (http://tools.niehs.nih.gov/ntp_tox)

·  Poncelet F., M. Mercier, and J. Lederer. 1980. Saccharin: Para forms of some impurities are not mutagenic inSalmonella typhimurium. Food Cosmet

·  Suzuki H., and N. Suzuki. 1988. Mutagenicity of saccharin in a human cell strain. Mutat Res 209:13-16.


Justification for selection of genetic toxicity endpoint
No one specific study is selected. All key studies for this endpoint addressing bacterial mutagenicity, mammalian mutagenicity and mammalian clastogenicity were all negative.

Short description of key information:
The substance has no structural alerts for mutagenicity, and a large database of performed studies, including high quality GLP studies according OECD guidelines covering in vitro baterial mutagenicity, mamalian mutagenicity and clastogenicity, as well as in vivo micronucleus studies, indicate that p-TSA does not have genotoxic properties.

Endpoint Conclusion: No adverse effect observed (negative)

Justification for classification or non-classification

The substance has no structural alerts for mutagenicity, and a large database of performed studies indicate that p-TSA does not have genotoxic properties.