Cyclohexane, oxidized, aq. ext.

Endpoint summary

Description of key information

COP acid and the read across ingredient, adipic acid, have very low acute toxicity. The oral and dermal LD50 in rats are > 5000 mg/kg bw. In an acute inhalation test  neither mortality nor symptoms were observed during and after 4 hour exposure to 7700 mg/m3 of adipic acid.

Key value for chemical safety assessment

Acute toxicity: via oral route

Endpoint conclusion

Dose descriptor:

LD50

Value:

5 560 mg/kg bw

Acute toxicity: via inhalation route

Endpoint conclusion

Dose descriptor:

discriminating conc.

Value:

7 700 mg/m³ air

Acute toxicity: via dermal route

Endpoint conclusion

Dose descriptor:

discriminating dose

Value:

7 940 mg/kg bw

Additional information

Read Across (Adipic Acid):

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

Oral toxicity:

"In rats, an LD50 value of 5560 mg/kg bw was established in a study similar to OECD TG 401 performed with single doses up to 10 000 mg/kg bw of adipic acid (99.8 %) administered as 50 % suspension in carboxymethyl cellulose vehicle. Mortality was seen during the first 48 hours. Lethal doses caused acute dilatation of the heart and acute congestive hyperaemia, ulceration of glandular stomach (bleeding-corrosive gastritis), pale liver, intestinal atony and reddening of intestinal mucosa. Animals that survived to termination at 14 days showed no gross pathological changes. The doses used in this test were in excess of the currently accepted limit dose (BASF 1978).

No signs of toxicity were observed following administration of a single dose of 5000 mg/kg bw of adipic acid (suspended in saline) to ten male rats (Litton Bionetics Inc. 1974).

In mice, an LD50 value of 1900 mg/kg bw was established after the administration of adipic acid (6 % solution in 0.5 % methyl cellulose) to groups of 13 male animals. Autopsy of animals that died during the experiment showed distention of the stomach and irritation and hemorrhage of the intestines as well as spastic contraction of the caecum. Initial mortality developed overnight and deaths continued throughout the first week, survivors appeared normal (Horn et al., 1957)."

Inhalation toxicity:

"In a study similar to OECD TG 403, neither mortality, toxic symptoms nor macroscopic pathological changes were observed in 20 rats exposed for 4 hours (nose only) to the maximal attainable concentration of 7700 mg/m3 of adipic acid (99.8 %) dust. 50 % of the particles had a MMAD below 3.5 µm."

Dermal toxicity:

"No lethality was reported in rabbits following occlusive dermal administration of 5010 (n = 1) and 7940 mg/kg bw (n = 2) of 40 % adipic acid in corn oil for 24 hours. Animals showed reduced appetite and activity and the viscera were normal at necropsy after 14 days observation. Due to the low animal number the study is of limited reliability, however the result is consistent with the low acute oral toxicity."

Acute toxicity other routes:

Limited studies are cited in IUCLID database prepared for the OECD/ICCA high production volume chemicals program in 2004. LD50 values are reported between 275 and 600 mg/kg bw after i.p. injection in mice and a LD0 of 2450 mg/kg bw was reported after i.v. injection in rabbits.

Human information:

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

"There are no acute toxicity studies in humans reported. No overt toxic symptoms were reported after oral administration of up to 7 g of adipic acid per day, for 10 days to one volunteer (100 mg/kg bw. per day) to investigate compound excretion (Weitzel, 1942 and 1947)."

Updated relevant information:

None

Overall:

Adipic acid is of very low acute toxicity. The oral LD50 in rats in a study similar to OECD TG 401 is approximately 5560 mg/kg bw. Clinical signs at lethal doses included acute dilatation of the heart and acute congestive hyperaemia, ulceration of glandular stomach (bleeding-corrosive gastritis), intestinal atony, pale liver and reddening of intestinal mucosa. The LD50 for mice was reported to be 1900 mg/kg bw. In an inhalation test similar to OECD TG 403 in rats neither mortality nor symptoms were observed during and after 4 hour exposure to 7700 mg/m3 of adipic acid. Reduced appetite and activity were the only effects reported following occlusive dermal administration of 7940 mg/kg bw of adipic acid to 2 rabbits for 24 hours.

Justification for classification or non-classification

Adipic acid is of very low acute toxicity. No classification is required according to the EU classification criteria 67/548/EWG and regulation no. 1272/2008 (GHS).