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Environmental fate & pathways

Endpoint summary

Administrative data

Description of key information

Additional information

Phototransformation in air

The atmospheric oxidation potential (AOP) predicted from the Epiwin program indicates that cyanuric chloride is not photolytically reactive (degradation half-life of > 15 year).

Hydrolysis

Measurements revealed a fast and stepwise hydrolysis of cyanuric chloride. The intermediate and final degradation products of cyanuric chloride were identified as 2,4-dichlor-6-hydroxy-1,3,5-triazine (first intermediate, DT50(pH 7.0, T=298.15 K ) = 0.52 h = 31.5 min), 2-chlor-4,6-dihydroxy-1,3,5-triazine (also named 6-chloro-1,3,5-triazine-2,4(1H,3H)-dione, sodium salt) (second intermediate, CAS no.: 32998-00-8, DT50 (pH 7.0, T=298.15 K)= 3.98 h =239.0 min ) and cyanuric acid (final degradation product, CAS no: 108 -80-5), respectively.

In this study the half-times for the first hydrolysis step of cyanuric chloride were determined to be

- DT50 (pH 2.0, T=298.15 K = 1.2 min

- DT50 (pH 4.0, T=313.15 K)= 1.65 min

- DT50 (pH 7.0, T= 298.15 K) = 3.47 min.

The rates of hydrolysis rise significantly for all three steps at acidic medium and are slower at basic pH (for T = constant).

The activation energy is idependent from pH and equal for the three hydrolysis steps.

Biodegradation

A read across approach was applied with the supporting substance 2-chlor-4, 6-dihydroxy-1,3,5-triazin, mono sodium salt. In a key study according to OECD guideline 301 E and EU-method C.4-B the biodegradation behaviour of the test item was assessed. The test revealed that after an exposure period of 28 days no biodegradation occurred. Therefore, the test item was considered to be not ready biodegradable. Additionally the biological oxygen demand of the test item was investigated in a supporting study. After an exposure period of 5 days the test revealed that the BOD was 5% at a concentration of 2 mg/L test item and 0 % at a concentration of 10 mg/L.

Bioaccumulation:

The bioaccumulation potential of the test item was estimated by calculation of the BFC with EPIWIN software using BCFBAF v1.5 the ACD/Log D Suite program. A BCF value of 0.293 L/kg wwt and a log Kow of 2.14 were calculated. As cyanuric chloride hydrolyses rapidly in water, it is considered to be unlikely that the test item has potential for bioaccumulation.

Adsorption/desorption:

The adsorption / desorption of the test item was estimated by calculation of the log Koc with EPIWIN software using KOCWIN and the ACD/Log D Suite program. A log Koc value of 1.902 and a log Kow of 2.14 was calculated. As cyanuric chloride hydrolyses rapidly in water it can be considered to be unlikely that the test item has potential for adsorption / desorption.