diuron (ISO); 3-(3,4-dichlorophenyl)-1,1-dimethylurea

Endpoint summary

Additional information

Diuron - Mutagenicity in bacteria

In a reliable study, the mutagenic potential of Diuron was tested in Salmonella typhimurium strains TA 1535, TA 1537, TA 98 and TA 100 equivalent to OECD Guideline 471. Test substance concentrations of 0, 125, 250, 500, 1000 and 2000 µg/plate in DMSO were tested with and without the addition of a rat liver homogenate metabolising system (S9-mix).No increase in the frequency of revertant colonies compared to concurrent negative controls were observed in all tested strains, neither in the presence nor in the absence of metabolic activation. Thus, Diuron did not induce gene mutations in the four tested Salmonella strains under the given test conditions (Herbold, 1984). In general, this negative result was confirmed in additional tests using the same Salmonella strains as well as the tester starin WP2 uvrA (Becker, 2008, Gareiss, 2008).

 

Diuron - In vitro cytogenicity in mammalian cells

A reliable in vitro mammalian chromosome aberration test was performed with Diuron in Chinese hamster ovary (CHO) according to OECD Guideline 473 (Shivaram, 1999). Diuron concentrations of 0, 90, 180 and 360 µg/mL were used but no evidence for the induction of chromosome aberrations was obtained in the presence and absence of metabolic activation while the respective positive control substances produced a statistically significant increase in aberrant metaphases under identical conditions.

 

Diuron - In vitro mutagenicity in mammalian cells

A reliable in vitro Mammalian Cell Gene Mutation Test was performed with Diuron in Chinese hamster ovary (CHO/ HPRT assay) according to OECD Guideline 476 (Rickard, 1985). The cells were treated with the test substance in duplicate, together with vehicle (DMSO) and positive controls (ethylmethanesulphonate and 9, 10-dimethylbenz (a) anthracene). The test concentration without metabolic activation was: 0, 0.010, 0.500, 1.000, 1.125 or 1.250 mM. The test concentration with metabolic activation was: 0, 0.050, 1.000, 0.200, 0.500 or 0.750 mM.

The positive control materials induced marked increases in the mutant frequency indicating the satisfactory performance of the test and of the activity of the metabolising system. Diuron did not induce a dose-related or biologically significant increase in the mutation frequency at the HPRT-locus with and without activation. However, significant cytotoxicity was noted in the two trials with metabolic activation at 0.5 and 0.75 mM.

Diuron - in vivo micronucleus assay

A reliable micronucleus test in mice was conducted according to OECD 474 and EEC guidelines.After single i.p. treatment with 700 mg/kg bw Diuron no mortalities were observed, but all animals showed signs of toxicity.No increase in micronucleated PCEs over solvent control was noted at any sampling time point, so no indications of a clastogenic effect of Diuron were found.(Herbold, 1998). 

Short description of key information:
No mutagenicity in bacteria was observed in the study.
No clastogenic effects in mammalian cells could be observed.
No mutagenicity in mammalian cells could be observed.

Endpoint Conclusion: No adverse effect observed (negative)

Justification for classification or non-classification

The available data on genetic toxicity is conclusive but not sufficient for classification according to directives DSD (67/548/EEC) or CLP (1272/2008/EC).