Terphenyl

Endpoint summary

Key value for chemical safety assessment

Skin irritation / corrosion

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not irritating)

Eye irritation

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not irritating)

Additional information

Skin irritation/corrosion:

The key study for skin irritation/corrosion is a K1, GLP study performed similar to OECD guideline 404, in which the Draize scoring system is used. New Zealand White rabbits were exposed to 0.5g of the test material for 24 hours under occlusive coverage upon both intact and abraded shaved skin. Subsequently, the excess material was wiped from the treated sites of the animals. Scorings were recorded 24 and 72 hours after topical application. Animals showing signs of irritation after 72 hours were further observed for signs of irritation on the seventh and tenth day after exposure. Only signs of slight erythema were observed.

Several supporting studies are available as well. A K2 study on Santowax MP also indicates that the substance is not an irritant. Furthermore, one K3 study on MCS-2073 indicates the substance is not irritating. There are three K4 studies present in the current IUCLID file of which one on Santowax R indicating the non irritating properties as well and then one on MCS-1980 suggesting the substance would be an irritant. The latter study is however not well documented and therefore it is difficult to judge the reliability of that study. The last study (K4) (Haley et al. 1959) describes the effects of different polyphenyl mixtures and of the individual terphenyl isomers. The two described mixtures are clearly not comparable to the current mixtures which are being produced and therefore not relevant for this assessment. The results on the isomers are relevant and indicate that the isomers are not irritating.

Eye irritation:

The K1 key study for eye irritation is performed according to GLP and similar to OECD guideline 405, in which the Draize scoring system is used. New Zealand White rabbits were exposed to a single dose of 76 mg of test substance via the eye. Signs of irritation were recorded on the first, second and third day after dosing. Only on the first day signs of irritation were noted in 3 of the 6 test animals. By day 2, all animals were free of irritation signs.

Furthermore, some supporting studies are available. A study on Santowax MP (K2), suggested mild irritation, but the effects appeared to be fully reversible resulting in categorization of the chemical as not irritating. The K3 study with MCS-2073 confirmed the results from the key study, namely that the substance is not irritating. The same was also shown for Santowax R and MCS-1980 in the respective K4 studies. There was one additional study available describing the effects of a polyphenyl mixture (Haley et al. 1959), however the composition of the mixture is clearly different from the currently produced mixtures and therefore these results are not taken into account.