Octahydro-2H-1-benzopyran-2-one

Endpoint summary

Description of key information

Abiotic degradation:

Air: Based on estimation with the QSAR model Aopwin the substance undergoes in air rapid degradation after reaction with hydroxyl radicals. The DT50 value after reaction with hydroxyl radicals is 8.2 hours. The substance will not reach the stratosphere and is therefore not considered to be a long-range transported chemical in air.

The substance does not have an ozone depletion potential because it does not contain halogens and does not have the potential to reach the stratosphere (GHS, 6th Edition, CLP, 2008).

Water: The rate of hydrolysis of the substance at pH values normally found in the environment (pH 4-9) was determined in a GLP-compliant study according to OECD 111. The half-life time of the substance at 25°C and pH 4, pH 7 and pH 9 was determined to be > 1 year, 17 days and 8.4 hours, respectively. The substance is anticipated to be hydrolysed in the lactone ring forming a monocyclic secondary alcohol on one end and an acid at the other end.

Biotic degradation:

In a biodegradation screening study (OECD TG 301D), after 28 days exposure of river water to 2 mg/L substance, 71% biodegradation was observed. Based on these findings the substance is considered to be readily biodegradable.

Bioaccumulation:

Aquatic and terrestrial organisms: Based on the log Kow it can be concluded that the substance has no bioaccumulation potential with calculated BCF values for aquatic and terrestrial organisms of 3.09 and 1.14 L/kg ww, respectively.

Transport and distribution:

The adsorption/desorption screening study was not conducted as the substance has a low octanol water partition coefficient. For the CSA, the Koc is therefore calculated. Using the measured log Kow (1.4) and the default QSAR used in EUSES - Koc = 10.47*(Kow)^0.52 - the Koc is calculated to be 56 L/kg and the log Koc 1.75. Based on this value it may be concluded that the substance has low potential for adsorption to solid surfaces.

A Henry's law constant of 4.1E-4 Pa·m³/mol (at 12 °C) was calculated in EUSES (Vap pressure 0.21 Pa at 24°C, 154.21 molecular weight and 39953 mg/l at 24°C water solubility). Based on this value the substance will not partition from water to air.

Based on Level III environmental distribution modelling using EPISUITE (assuming equal and continuous releases to air, water and soil) using the CAS number 4430-31-3, it is estimated that the majority of the substance released to the environment will partition mainly into soil (71.6%) and water (26.6%) with small amounts to air (1.63%) and sediment (0.18%).

The SimpleTreat model, which is incorporated in EUSES, simulates the distribution of the substance in a Sewage Treatment Plant (STP). Model calculations show that 86.9% of the substance will be degraded and that 1.7E-4 %, 12.6% and 0.525% will partition to air, water and sewage sludge, respectively.