Cinchonine

Endpoint summary

Additional information

Stability:

Data on the stability of cinchonine are only available for phototransformation.The calculated phototransformation of cinchonine in air, calculated from the hydroxyl radical turn over rate is 126.3473 E-012 cm^3/molecule/s (1.09 E-05 cm^3/molecule/d). Therefore, we consider phototransformation in air to be negligible. These results are calculated using AOP v1.92, expecting, that phototransformation appears at a constant rate. The EPA recommends that empirical measures provide better results. However, empirical studies have not been done, so that we adapt the prediction.

Biodegradation:

The read across substance cinchonine hydrochloride was tested in a CO2 Evolution Test according to the OECD Guideline 301 B for 28 days (and 29 days after acidification) to determine whether the test substance is readily biodegradable. This study showa high variation in the degradation behaviour which is determined by different end of the lag phase in the different replicate vessels with cinchonine hydrochloride. In vessel 7 the lag phase ended between day 4 and 7, in vessel 8 the lag phase ended between day 7 and 11, while in vessel 9 the lag phase continued over 14 days. On day 28 (after acidification) the degradation in vessel 7 and 8 reached extents between 94.9 and 96.9%. Because of the long lag phase the degradation extent in vessel 9 didn’t reached the plateau and was significant lower (72.0%) at the end of the test. The criterion of the difference of extremes of replicate values at the end of the test was therefore fulfilled in two of three test vessels. Because of the differing lag phases the 10-d-window was evaluated separately. The 10-d window was reached in all three test vessels. In vessel 7 and 8 the degradation extents were already on day 11 above 60%. For finding the exact position of the 10-d-window for the degradation in vessel 9 we had to interpolate the degradation extent between the days 14 and 28. The first day with a degradation extent of ≥10% was day 16. On day 26 the degradation extent was 61.9%. Therefore, the pass level for ready biodegradation (60% ThCO2 within a 10-d window) was reached in all three test item replicates and cinchonine can be considered as readily biodegradable.

Bioaccumulation:

The given BCF, BAF and Biotransformation half-life estimations from the models for cinchonine show, that cinchonine has a low accumulation potential. Nevertheless, the EPA recommends that EPI Suite is a screening-level tool and should not be used if acceptable measured values are available. However, empirical studies have not been done, so that we consider a BCF of 18.7 L/kg, BAF of 28.1 L/kg and biotransformation half-life of 0.119 days.

Transport and distribution:

The EPI Suite v.4.11. results show that, cinchonine adsorbs to carbon and in the environment. The major amount is distributed to soil. The estimated Henrys law constant of cinchonine is approx. 1.47E-009 Pa-m3/mole.