Registration Dossier

Environmental fate & pathways

Endpoint summary

Administrative data

Description of key information

Additional information

In contact with water 1,3,5 trioxane will hydrolyse slowly under environmental conditions (half-life >1 yr). A calculation on Henry´s law constant indicates that trioxane will not evaporate from the water surface into the atmosphere (H = 0.02 Pa*m³/mol). After emission into the atmosphere, the substance will be slowly degraded by indirect photochemical processes (half-life of 37.5 h). Furthermore, adsorption of 1,3,5-trioxane to the solid soil phase is not expected (log Koc = -0.416). Thus, the substance will mainly distribute into water (ca. 80%) and air (ca. 20%). Based on the calculated log Pow (-0.5) of 1,3,5-trioxane a bioaccumulation is not expected. A modified Zahn-Wellens test was conducted using a closed system with sodium nitrate as the oxygen source. In this study, more than 90% of the DOC was removed in 18 days. Another study showed that trioxane is easily removed from water by volatilization. Therefore, trioxane was classified to be easily eliminated from water and inherently biodegradable.