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Description of key information

Experimental toxicokinetic studies are not available. The log Kow does not point to a bioaccumulation potential. Oral and dermal absorption was shown in toxicological studies.

Key value for chemical safety assessment

Bioaccumulation potential:
no bioaccumulation potential

Additional information

PERKALINK 900 is used as anti-reversion agent in the manufacture of natural rubber articles such as the treads of tyres, conveyor belts and solid tyres. Anti-reversion agents help repair the sulfur cross-links that break as a result of exposure of the rubber articles to high temperatures resulting from both friction and the vulcanising process. After processing the substance is chemically bound to the rubber matrix. PERKALINK 900 is considered as mono constituent.

PERKALINK 900 is handled as dust-free pastilles with a very low vapour pressure under normal ambient conditions (0.00005 Pa at 20°C, Cowlyn, 1993). Inhalation exposure to the vapour is therefore not to be expected.

Physicochemical properties of PERKALINK 900:

Molecular weight: 324 g/mole

Water solubility: 40.8 mg/L at 20°C

Partition coefficient: log Kow = 2.22

The following remarks on toxicokinetics are based on the physico-chemical properties of PERKALINK 900 and on toxicological data. Experimental studies on toxicokinetics were not performed.

Absorption

The physicochemical characteristics of PERKALINK 900 (log Kow of 2.22) and the molecular mass are in the range suggestive of absorption from the gastrointestinal tract subsequent to oral ingestion. This is confirmed by data obtained in a 2-generation feeding study on rats which showed signs of systemic toxicity.

Dermal absorption of PERKALINK 900 is favoured by its log Kow. The water solubility is also in the range that allows dermal penetration. PERKALINK 900 is no skin irritant after single dermal exposure but it is a strong skin sensitizer when repeatedly applied to the skin. The latter implies that some dermal penetration did occur.

PERKALINK 900 is a strong irritant to mucosal membranes.

Metabolism

Based on the results of several mutagenicity tests it can be assumed that no DNA-reactive metabolites will be generated in mammals in the course of hepatic biotransformation of PERKALINK 900.

Elimination

The log Kow of 2.22 does not indicate a relevant bioaccumulation potential of PERKALINK 900.