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Classification & Labelling & PBT assessment

PBT assessment

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PBT assessment: overall result

PBT status:
the substance is not PBT / vPvB
Justification:

NaDCC has Log Pow < 1, rapidly hydrolyses to CYA, and is highly soluble in water. An estimation of the log Kow was - 0.0056. In addition, the chlorinated isocyanurates are highly reactive with many biological compounds such as proteins and enzymes and are therefore unlikely to bioaccumulate. As the substance hydrolyses rapidly in use to release available chlorine moieties in the form of HOCl and CYA, it does not meet the criteria for bioaccumulation or persistence.

The chlorinated isocyanurates are unstable in the environment, because the free available chlorine is rapidly reduced. CYA, or its salt, is the stable degradation product. Therefore, CYA, or its sodium salt, is the substance of interest for chronic ecotoxicity studies. The substance is not classified for toxicity based on its effects in the aquatic environment, as the long-term toxicity test performed using the monosodium salt of cyanuric acid (equivalent to 75.6% cyanuric acid) gave a NOEC of 756 mg/L for the fish juvenile growth test. Similarly a Daphnia magna reproduction study produced a NOEC of 121 mg/L.

The chlorinated isocyanurates are unstable in the body, particularly the stomach, because the free available chlorine is rapidly reduced. CYA, or its salt, is the stable degradation product. CYA has shown no evidence of carcinogenicity via oral exposure in drinking water in doses up to 5375 ppm (equivalent to doses of 1523 mg/kg bw/day for males, and 1582 mg/kg bw/day for females) in carcinogenicity studies in both rat and mouse. Therefore no classification for carcinogenic effects is required for troclosene sodium.

Furthermore there is no evidence of genotoxic potential of CYA in in-vitro studies with and without metabolic activation and in an in-vivo rat chromosome aberration study. Classification for genotoxicity is therefore not warranted.

In the rat teratogenicity study, monosodium cyanurate administered by gavage did not produce a teratogenic response at a dose of 5000 mg/kg bw/day or below. In the rabbit teratogenicity study there was no evidence of developmental toxicity in any of the treated groups.

Oral exposure of monosodium cyanurate in the rat fertility study did not produce any consistent effects on reproductive parameters or offspring toxicity.

The substance is therefore not classified as carcinogenic, mutagenic or toxic for reproduction.

Finally the substance is not classified for chronic toxicity as T, R48 or Xn R48, according to Directive 67/548/EEC or STOT RE category 1 or 2 according to Regulation EC No. 1272/2008.

The substance does not fulfill the PBT or vPvB-criteria and is therefore not considered persistent, bioaccumulative or toxic.