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Description of key information

Repeated Dose Oral 90d – NOAEL = 300 mg/kg for rats (similar to OECD TG 408)
Repeated Dose Inhalation 12 month – NOAEL >= 900 mg/m3 for rats (similar to OECD TG 413), read-across material C9 Aromatics

Key value for chemical safety assessment

Repeated dose toxicity: via oral route - systemic effects

Endpoint conclusion
Dose descriptor:
NOAEL
300 mg/kg bw/day

Repeated dose toxicity: inhalation - systemic effects

Endpoint conclusion
Dose descriptor:
NOAEC
900 mg/m³

Additional information

Oral: C10-C12 Aromatics are expected to have a low order of repeated dose toxicity by the oral route of exposure.  All tests were performed in a manner similar or equivalent to currently established OECD guidelines. In a repeated dose study where the test substance, C10-C12 Aromatics, was administered via oral gavage, signs of toxicity were observed and characterized at doses of 600 mg/kg.  The severity and frequency of the responses increase with increasing doses.  Noted changes include alterations to hematology (hematocrit, hemaglobin, MCHC), changes to thyroid follicular epithelial cells, and increases in the hemosiderin in macrophages.  The effects had reversed completely after the 4-week recovery period. Based on these observations, the repeat oral dose NOAEL is 300 mg/kg for C10-C12 Aromatics.

 

Inhalation: In a 12 month repeated dose study where the read-across substance C9 Aromatics were administered via inhalation, no signs of toxicity were observed at the maximum concentration of 900 mg/m3. Based on these observations, the repeat inhalation concentration NOAEL is >900 mg/m3.

Justification for classification or non-classification

In a repeated dose study where C10-C12 Aromatics was administered via oral gavage, signs of toxicity were observed and characterized at doses of 600 mg/kg.  The severity and frequency of the responses increase with increasing doses.  Noted changes include alterations to clinical chemistry, changes to thyroid follicular epithelial cells, and increases in the hemosiderin in macrophages.  Based on these observations, the repeat oral dose NOAEL is 300 mg/kg for C10-C12 Aromatics. In a 12 month repeated dose study where the read-across substance C9 Aromatics were administered via inhalation, no signs of toxicity were observed at the maximum concentration of 900 mg/m3. Based on these observations, the repeat inhalation concentration NOAEL is >900 mg/m3.

 

These findings do not warrant the classification of C10-C12 Aromatics as a repeated dose toxicant under the new Regulation (EC) 1272/2008 on classification, labeling and packaging of substances and mixtures (CLP) or under the Directive 67/518/EEC for dangerous substances and Directive 1999/45/EC for preparations.