Cyclohexane-1,4-dicarboxylic acid

Endpoint summary

Additional information

The aquatic toxicity of 1,4 -cyclohexanedicarboxylic acid (CHDA) was measured using vertebrates (fish), invertebrates (6 species), plants (aquatic algae), and wastewater treatment microorganisms. The vertebrate and invertebrate tests were conducted simultaneously in a pre-GLP study using seven species (fish plus six invertebrate species). The test was conducted using two nominal concentrations of 10 and 100 mg/L along with a control. As CHDA is not volatile and does not have a tendency to sorb to particles or glassware, the conduct of the test using nominal concentrations appears reliable. No effects were observed with Daphnia magna at 48 hours, or with the remaining fish and invertebrate species exposed for 96 hours (i.e., EC/LC50 > 100 mg/L, NOEC ≥ 100 mg/L). A 72 hour OECD 201 study with algae was conducted according to GLP. The results of that study were an ErC50 of 22 mg/L and ErC10 and ErC20 of 15 and 16 mg/L respectively. The NOEC value for this study was not deemed to be reliable due to a lack of statistical sensitivity in the hypothesis test. The ErC10 or ErC20 should be used as the NOEC for this study according to the method guidance. The inhibition of respiration in wastewater treatment microoganisms was measured over a 5 hour period. In that study the highest concentration tested, 750 mg/L, was not inhibitory to the microorganisms (NOEC ≥ 750 mg/L).