9917E

Endpoint summary

Key value for chemical safety assessment

Bioaccumulation potential:

low bioaccumulation potential

Additional information

The substance is a decasodium salt of a sulfonated and carboxylated triazine containing compound. The high molecular weight may, theoretically, preclude absorption. No predictions about toxicokinetic behaviour can be made from the chemical structure. The notified substance tested is a powder prepared by drying but will only be used as a solution, so inhalation exposure is not anticipated. It is stable to hydrolysis, so exposure to degradants is not expected. Most of the data used for this assessment is derived from studies conducted on the analogue substance 1 (refer to IUCLID chapter 13).

1) ABSORPTION No treatment related effects were seen in an acute oral toxicity study on the notified substance or in an acute dermal study conducted the analogue substance 1 (refer to IUCLID chapter 13)

. In a repeated dose oral toxicity study

the analogue substance 1 (refer to IUCLID chapter 13)

, however, treatment related kidney changes were observed, which indicate that absorption could occur from the gastro-intestinal tract. The notified substance has a low log Pow value, which suggests poor absorption by passive diffusion, but it is very water soluble and may therefore show higher lipid solubility than is suggested by the Pow value. Any absorption would be expected to be pH dependant since the notified substance is a polybasic salt of both weak and strong acid groups. Absorption would, therefore, be favoured in the acid environment of the stomach, whilst interaction with counter ions could, potentially, increase lipophilicity.

2) DISTRIBUTION There is no experimental evidence to indicate potential distribution of any absorbed substance, other than to the route of excretion. Bioaccumulation is probably unlikely, in view of the high water solubility. A contact sensitisation study conducted on the analogue substance 1 (refer to IUCLID chapter 13)

was negative, which might imply that the substance would not be expected to bind to proteins.

3) METABOLISM None of the studies conducted on the notified substance or

the analogue substance 1 (refer to IUCLID chapter 13)

provide any convincing information about metabolism. From the chemical structure, enzymic cleavage might be expected possibly with production of sulfonamides and subsequent conjugation reactions. The high water solubility of the parent substance, however, suggests that excretion may occur without biotransformation.

4) EXCRETION The kidney effects seen in the repeated dose oral toxicity study conducted on

the analogue substance 1 (refer to IUCLID chapter 13) s

uggest that excretion in urine occurs. The water solubility of the parent substance and the possible metabolites indicate this to be the most likely route of excretion, although high molecular weight substances are sometimes eliminated in bile. The parent substance is not sufficiently volatile for elimination via the lungs in expired air.