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Description of key information

Calculation with HYDROWIN v2.00 (EPIWIN software by US-EPA): detected hydrolysable substance class: Epoxides 
Half-life for hydrolysis with chlorine in the main component: ~ 44 years (pH 7, 25 °C)
Half-life for hydrolysis without chlorine in the main component: ~ 29 years (pH 7, 25 °C)

Key value for chemical safety assessment

Additional information

The hydrolysis potential of the test substance was predicted by the computer program HYDROWIN v2.00 (EPIWIN software) by US-EPA (Chemservice S.A., 2012). The program estimates the hydrolysis rate constants for specific organic classes and, furthermore, a chemical´s half-live under typical environmental conditions is also determined.Only esters, carbamates, epoxides, halomethanes (containing 1-3 halogens), specific alkyl halides and phosphorous esters can be estimate, since these are specific organic classes, which are able to undergo hydrolysis. When present, various hydrolysable compound-types will be identified. Chemical fragments of the test substance are not available from the fragment library included in the computer tool. Therefore substitutes have been used. Epoxides were detected as hydrolysable parts, whereby the estimated rate constant does not include the neutral hydrolysis rate constant. However, if this neutral rate constant is important, the HYDROWIN predictions will under-estimate the actual rate.The main component may contain chlorine, which has an influence onto the hydrolysis rate constant as followed: Including chlorine, hydrolysis will occur on atom numbers 13 and 19. The corresponding rate constants are 2.51E-3 L/mol-sec at both positions. The total, acid-catalysed rate constant at 25 °C is predicted as 5.02E-3 L/mol-sec. Without chlorine, the hydrolysis may occur on atom numbers 9, 15 and 18 with identical rate constants of 2.51E-3 L/mol-sec. In this case, the total acid-catalysed rate constant at 25 °C is predicted as 7.52E-3 L/mol-sec. Concerning the half-life at a pH of 7, a time span of about 44 years is predicted if the component contains chlorine, otherwise the half-life will be around 29 years.

No GLP criteria are applicable for the usage of this tool, but due to the fact that it is a scientifically accepted calculation method the estimations performed are reliable with restrictions and can be used for the chemical safety assessment.