Biphenyl

Endpoint summary

Description of key information

Skin irritation / corrosion:
Only Klimisch 4 studies were identified. The available studies were used in a weight of evidence approach. Based on the available animal information biphenyl should not be considered as a skin irritant under normal conditions and use. 
Eye irritation:
Only Klimisch 4 studies were identified. The available studies were used in a weight of evidence approach. Based on the available animal data biphenyl should not be considered as an eye irritant
However, based on human information mentioned in the Annex I classification dossier, biphenyl (No. 601-042-00-8) is classified as Xi (irritant) and R36/37/38 (irritating to eyes, respiratory system and skin) under the Dangerous Substance Directive. Translation to the CLP regulation also yields a harmonized classification as skin and eye irritant. Because the references of the primary sources from which this human information was taken were not reported in the classification dossier, no evaluation of these data could be performed. By way of precaution, the substance will be considered as irritating to eyes and skin in the chemical safety assessment.

Key value for chemical safety assessment

Skin irritation / corrosion

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (irritating)

Eye irritation

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (irritating)

Respiratory irritation

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (irritating)

Additional information

Skin irritation / corrosion - animal data

Only Klimisch 4 studies were available for the skin irritation / corrosion endpoint. Therefore, the available animal information is used in a weight of evidence approach. Skin irritation tests were performed in rabbits. Adams et al. (1938) observed that single exposure to biphenyl solutions (5% solution in 95% ethanol or 5% solution in 95% olive oil) produced no irritation when tested on the ears. Repeated exposure to the alcoholic and olive oil solution produced reactions ranging from slight exfoliation to hair loss and hyperemia after two weeks of treatment (very slight intensity). Repeated exposure to the alcoholic and olive oil solution produced reactions ranging from very slight exfoliation (alcoholic solution) to edema and hyperemia (after 2 exposures to olive oil solution) and superficial necrosis after 12 exposures, when tested on the abdomen, however these effects were observed to be reversible. Biphenyl appears to be but very slightly irritating to the skin, principally because of its solid nature. The pure solid would probably not cause any irritation, except possibly under the most severe conditions. However, where contact is better as in the case of prolonged contact with solutions, an irritation might develop. Similar effects were observed by Day (1939). Carpenter (1949) studied the effects of 10% solution of biphenyl in acetone on the skin of the belly and did not observe any irritating effects. In addition, no irritation effects were observed by Haley et al. (1959) and Birch (1976). Based on the available animal information biphenyl should not be considered as a skin irritant under normal conditions and use.

Eye irritation - animal data

Only Klimisch 4 studies were available for the eye irritation endpoint. The studies of Carpenter (1949) and Birch (1976) were used in a weight of evidence approach. Carpenter (1949) observed only trace injury to the cornea of the rabbit eye when instilled in 0.5 mL amounts (15% solution in mineral oil). Birch (1976) observed slight erythema with copious discharge at 1 and 24 hours (after 24 hours exposure to biphenyl). At 48 hours, gradual improvement was observed and the observed effects were fully reversible within 72 hours. In conclusion, based on the available animal data biphenyl should not be considered as an eye irritant.

Skin and eye irritation - human data

In the Annex I classification dossier for biphenyl (No. 601-042-00-8), the following human data are reported on skin and eye irritation:

- Irritant to eyes, nose, respiratory tract and skin.

- Irritant effects have been noted in man after inhalation of 4400 µg/m3.

- Exposure to a mixture of diphenyl and diphenyl oxide below 7 ppm was irritating to eyes, nose, throat.

- Slight irritation to eyes and skin. No corneal injury. Respiratory irritation from overexposure to vapor (biphenyl 99-99.3%).

Based on this information, biphenyl is classified as Xi (irritant) and R36/37/38 (irritating to eyes, respiratory system and skin) under the Dangerous Substance Directive. Translation to the CLP regulation also yields a harmonized classification as skin and eye irritant. Because the references of the primary sources from which this human information was taken were not reported in the classification dossier, no evaluation of these data could be performed.

Justification for selection of skin irritation / corrosion endpoint:
weight of evidence approach used to address the endpoint

Justification for selection of eye irritation endpoint:
weight of evidence approach used to address the endpoint

Effects on skin irritation/corrosion: irritating

Effects on eye irritation: irritating

Effects on respiratory irritation: irritating

Justification for classification or non-classification

Based on the available animal experimental data, the substance does not need to be classified as an eye or skin irritant. However, as is clear from the Annex I classification dossier for biphenyl (No. 601-042-00-8), the substance is classified as Xi (irritant) and R36/37/38 (irritating to eyes, respiratory system and skin) under the Dangerous Substance Directive, based on evidence for irritation in humans. Translation to the CLP regulation also yields a harmonized classification as skin and eye irritant - category 2. Because the references of the primary sources yielding evidence for irritation in humans were not reported in the classification dossier, no evaluation of these data could be performed. By way of precaution, the harmonized classification should therefore be followed.