1-Propanol, 2-methyl-3-[(1,7,7-trimethylbicyclo[2.2.1]hept-2-yl)oxy]-

Endpoint summary

Additional information

Abiotic degradation:

Air: Based on estimation with the QSAR model Aopwin, Bornafix undergoes in air rapid degradation after reaction with hydroxyl radicals (the decrease with ozone could not be calculated). The DT50 values after reaction with hydroxyl radicals is 3.6 hours. The half-life time of the substance is < 2 days. 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 (EU CLP, 2008, and its amendments).

Water: In a study according to EU Method C7 Bornafix has been found to undergo significant hydrolysis at 50°C at pH 4, 7 and 9 over a period of five days. The results indicate that at 25°C, the test substance will possess half-life times of between 1 day and 1 year at pH 4, 7 and 9 but a DT50 could not be determined. Based on the chemical structure of Bornafix no hydrolysis is expected because the substance contains an ether and an alcohol which are not hydrolysable groups. Therefore the substance is considered hydrolytically stable and thus its DT50 is > 1 year.

Biotic degradation:

Two studies are available to assess the ready biodegradability of Bornafix. Both the Closed bottle test (OECD301D) and the CO2 Evolution study (OECD 301B) showed 2% biodegradation after 28 days. The Closed bottle test was identified as the key study as this method is more suitable for low water soluble and somewhat volatile substances. Based on the data available it can be concluded that the substance is not readily biodegradable under the conditions of these tests.

Bioaccumulation:

Bornafix is expected to have low bioaccumulation potential using the log Kow of 3.86 as a key parameter for the prediction of the BCF for aquatic and terrestrial organisms, which results in values of 381 and 87.8 L/kg ww, respectively.

Bioaccumulation in air-breathing organisms: The substance fulfils the screening criteria for bioaccumulation of air-breathing organisms when using the Koa predictor of EpiSuite. When using the Log Pblood-air partition coefficient, the criteria are not met because the value is 4.0, which is < 5 (Koa cut off). In addition, the substance is metabolised (OECD Toolbox and Xenosite) and is excreted via the kidneys as seen in the male rat. Therefore there is no bioaccumulation in air-breathing organisms.

Transport and distribution:

The substance is a moderately lipophilic substance with a log Kow of 3.86. The sorption to organic matter has been determined and the log Koc value is 3.23. This indicates that the substance will have some potential to adsorb to sediment/soil.

To assess the volatilisation potential of the substance a Henry's law constant was calculated using EUSES, which gave a result of 2.43 Pa. m³/mol at 25°C. From the distribution modelling results it can be concluded that volatilisation is of minor importance in the environmental behaviour of the substance. At environmental conditions of 12oC the value will be 1.16 Pa. m³/mol.

Based on Level III distribution modelling using EPISUITE (assuming equal and continuous releases to air, water and soil) using the Smiles notation: CC(COC1CC2CCC1(C)C2(C)C)CO and the measured physico-chemical parameters as input, it is estimated that the majority of the substance released to the environment will partition mainly into soil (83.2%) and water (16.6%) with small amounts to sediment and air (both <1%).

The SimpleTreat model, which is incorporated in EUSES, simulates the distribution of the substance in a Sewage Treatment Plant based on vapour pressure, water solubility, log Kow and biodegradability. The model predicts that 0% of the substance will be degraded and that the substance will mainly partition to water (81%), with some part going to sludge (17.2%) and a minor part to air (1.81%).