Cyclohexane, oxidized, non-volatile residue

Endpoint summary

Key value for chemical safety assessment

Skin sensitisation

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not sensitising)

Additional information:

Cyclohexane, oxidized, non-volatile residue (NVR) is not a skin sensitizer based on a guinea pig maximalisation study.

Supporting Studies (Read Across to Cyclohexane oxidized, aqueous extract and Adipic Acid :

A GLP OECD 429 LLNA guideline study on the closely related Cyclohexane oxidized, aqueous extract did not indicate skin sensitisation.

Adipic Acid - Hazards identified by OECD/ICCA high production volume chemicals program in 2004:

Animal data:

"There is only one sensitisation study available and it produced no evidence of a sensitising action but its reliability can not be fully assigned. Groups of 10 guinea pigs were given series of four sacral intradermal injections, one each week over a three-week period, which consisted of 0.1 ml of a 1.0 % solution of adipic acid (99.99 %) in water. Following a two-week rest period, the test animals were challenged for sensitisation by applying, and lightly rubbing in, approximately 0.05 ml of a 50 % and 25 % suspension of the test material in propylene glycol on the shaved intact shoulder skin. A group of 10 previously unexposed animals received similar applications at the time of challenge to provide direct comparison of the challenge reactions on the skin of similar age. The compound produced very mild to no skin irritation to previously unexposed guinea pigs and did not cause sensitisation (Haskell 1974). The study design does not accord to modern guidelines because the number of animals per group was low, no data were presented to justify the induction concentration used, no adjuvant was used, and no positive control or historical data were presented."

Human data:

"Despite the wide use of adipic acid, only very few cases of skin or respiratory tract reactions are reported: A positive patch test reaction to adipic acid (probably 1 % in alcoholic solution) was reported in a 51-year-old machine repairman with a 3- to 4-year history of work-related dermatitis of the hands and other exposed sites when working with powders in the synthesis of polyesters (Guin 2001). Delayed cutaneous hypersensitivity to adipic acid was reported in a patch test (100 %) with a laboratory worker in a factory producing polyester resins. No further details are available in this case (Malten and Zielhuis 1964)."

Migrated from Short description of key information:
Cyclohexane, oxidized, non-volatile residue (NVR) is not a skin sensitizer based on a guinea pig maximalisation study. A GLP OECD 429 LLNA guideline study on the closely related Cyclohexane oxidized, aqueous extract supported this result. Another study on Adipic Acid, a main component of NVR, also supported the conclusion.

Justification for selection of skin sensitisation endpoint:
The in-vivo study on the Cyclohexane oxidized, non-volatile residue was selected as a key study. A LLNP study on Cyclohexane oxidized, aqueous extract was selected as a supporting study.

Respiratory sensitisation

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information:

Cyclohexane, oxidized, aquous extract (COP Acid) has not been studied for respiratory sensitization but is not expected to be a respiratory sensitiser.

Read Across (Adipic Acid):

Hazards identified by OECD/ICCA high production volume chemicals program in 2004: "Despite the wide dispersive use of adipic acid, only very few cases of skin or respiratory tract sensitisation reactions are reported in humans. Overall, sensitisation is not expected for adipic acid."

Migrated from Short description of key information:
no valid animal data available

Justification for classification or non-classification

Cyclohexane, oxidized, aquous extract (COP Acid) and its primary component, adipic acid, are not sensitizing; no classification is required according to the EU classification criteria 67/548/EEC (DSD) and regulation no. 1272/2008 (CLP).