2022/06/29 by Hartwig, Andrea, MAK Commission
#2 #3 #4 #5-triazin #5-triazine #6-Trichlor-1 #6-trichloro-1 #Atemtrakt #Cyanurchlorid #Cyanurylchlorid #Gefahrstoff #MAK value #MAK-Wert #Reizwirkung #Sensibilisierung #Trichlorcyanidin #cyanuric chloride #cyanuryl chloride #hazardous substance #irritation #maximale Arbeitsplatzkonzentration #maximum workplace concentration #respiratory tract #retrospective cohort study #retrospektive Kohortenstudie #s-Triazintrichlorid #s-triazine trichloride #sensitization #trichlorocyanidine
paper · doi:10.34865/mb10877e7_2or
The German Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area has evaluated data for cyanuric chloride [108-77-0108-77-0] considering all toxicological end points. Unpublished study reports and publications are described in detail. Cyanuric chloride is irritating to the nose, eyes and throat of workers (according to earlier studies at about 0.3 mg/m3) and corrosive to the skin and eyes of rabbits and rats. The model best suited to estimate a long-term exposure threshold for workers with respect to lung function loss is based on a calculated cumulative exposure of 0.3 mg/m3-years. An irritant effect was not reported. As wearing a protective mask was obligatory for workers exposed to higher cyanuric chloride concentrations, the extent to which the workers in this study were exposed is unclear. No NOAEC for repeated exposure of humans is known. A 90-day inhalation study with rats observed a small increase of inflammatory cells in the nose without other changes in the mucosa at 0.032 ml/m3 (0.25 mg/m3); the NOAEC is 0.0065 ml/m3 (0.05 mg/m3). A maximum concentration at the workplace (MAK value) of 0.001 ml/m3 has been established based on the rat NOAEC after considering extrapolation to humans, a possible increase of effects with long-term exposure and the preferred value approach. Cyanuric chloride is classified in Peak Limitation Category I because of its local effects. As the human odour threshold is about 0.0025 ml/m3, an excursion factor of 2 is set, although a NOAEC has not been established for sensory irritation in humans. A developmental toxicity study in rats determined a NOAEC of 50 mg cyanuric chloride/kg body weight and day, which corresponds to a concentration of about 11.5 ml/m3 after toxicokinetic scaling; the margin to the MAK value is sufficiently large. Therefore, damage to the embryo or foetus is unlikely when the MAK value is not exceeded and cyanuric chloride is assigned to Pregnancy Risk Group C. Cyanuric chloride is not mutagenic in vitro or clastogenic in vivo and no studies in germ cells are available. No carcinogenicity study was performed. Cyanuric chloride shows a skin sensitizing potential in animals and is therefore designated with “Sh” (for substances which cause sensitization of the skin). Data relating to a potential sensitization of the airways are not conclusive. The dermal absorption is expected to be low at non-irritating concentrations and does not contribute significantly to systemic toxicity.