Amines, C12-14-tert-alkyl, C14-18 and C18-unsatd.-alkyl phosphates

Endpoint summary

Additional information

Soil Adsorption

The soil adsorption coefficient (Koc) of Reaction Products of alcohols, C14-18, C18 unsat., esterified with phosphorus pentoxide and salted with amines, C12-14,-tert-alkyl can not be determined experimentally. OECD 121 / EU Method C.19 is not applicable for this substance type. Since the Koc is an important parameter for the chemical safety assessment (CSA), it was predicted with the scientifically accepted QSAR program KOCWIN v2.00 (EPIWIN software) by US-EPA (Chemservice S.A., 2013). Based on the substance characterisation (UVCB substance), two different representatives structures were used for this approach. For the first representative structure, the traditional method gives a logKoc of 6.46 L/kg and the MCI method reveals a value of 9.33 L/kg as result. The second structure reveals logKoc values of 10.99 L/kg and 14.06 L/kg concerning the traditional and MCI method, respectively. The MCI method is taken more seriously into account due to the fact, that it includes improved correction factors.

Henry´s Law constant

EUSES v2.1 was utilized in order to calculate the Henry´s Law constant, since the EPIWIN software HENRYWIN give only "incomplete results"(Chemservice S.A., 2013b). This parameter is calculated based on temperature-corrected experimental vapour pressure and water solubility. Related to 25 °C, a Henry´s Law constant of 0.944 Pa*m³/mol was calculated.

Distribution modelling

Distribution modelling for "Reaction Products of alcohols, C14-18, C18 unsat., esterified with phosphorus pentoxide and salted with amines, C12-14,-tert-alkyl" was performed using two representative structures of the target UVCB substance (Chemservice S.A., 2013). The Level III fugacity model of the scientifically accepted computer program EPIWIN by US-EPA was used for this purpose. The executable file is called LEVEL3NT.EXE.The software is no stand-alone version and it contains a direct adaption of the Level III fugacity model developed by Mackay (1991) and Mackay et al. (1996). Level III modelling assumes a steady-state, but no common equilibrium conditions between the different environmental compartments. Four main compartments are concerned: air, water, sediment and soil. Between these compartments, mass transport is modeled via volatilization, diffusion, deposition and runoff. A fixed temperature of 25 °C is assumed.No substance properties are entered manually, thus default values are used.

In general, disappearance of a chemical occurs via two processes: reaction and advection. The abiotic or biotic degradation belongs to reaction, whereas the removal from a compartment through losses other than degradation is called advection. The rate of advection is determined by a specific flow rate, which may be specified by the user. Furthermore, the user can specify emission rates; otherwise the default emission rate is equal amounts to air, water and soil. For the sediment compartment, no direct emissions are considered.If half-lives in the different compartments are known, the values should be entered manually. Otherwise, EPIWIN software BIOWIN (Biowin 3 – Ultimate Biodegradation Timeframe) and AOPWIN are used to make these estimations by default. If a chemical is susceptible to abiotic hydrolysis, HYDROWIN may be able to provide the half-life. If a combination of hydrolysis, photolysis and biodegradation is likely for the compound, the half-lives shall be converted to rate constants and added together. The resulting overall half-life should be entered into the modelling.The output of Biowin 3 cannot be used directly by the Level III mass balance model. The mean value is converted to a half-life using a set of conversion factors, which consider that 6 half-lives constitute complete degradation with first-order kinetics.

Ultimate biodegradation is generally slower under anaerobic conditions than under aerobic conditions. The program concerns aerobic conditions; only for sediment an anaerobic environment is assumed. The rate of ultimate degradation in sediment is on average one-ninth (1/9) of that in the water column. A further adjustment is taken into account: In general, the biodegradation rate in soil is, on average, one-half (1/2) that in water. Therefore, a half-life in soil twice that estimated for water is assigned. The default environmental emission rates are 1000 kg/h to air, water and soil (sediment: 0 kg/h), which may be altered manually. The advection lifetimes of the substance in air, water and sediment compartments are set to the default values of 100, 1000 and 50000 hours, respectively. These lifetimes are used to determine the advective flow rate (m³/h). If no advection to any compartment is expected, the lifetime should be set to some arbitrarily large value (such as 1E20); this effectively changes the advective flow rate to zero. A soil Koc value is also required for the fugacity model. By default, the connectivity-based adsorption coefficient is used (MCI result by KOCWIN). Concerning “Reaction Products of alcohols, C14-18, C18 unsat., esterified with phosphorus pentoxide and salted with amines, C12-14,-tert-alkyl”, the observed environmental tendencies do not differ when comparing both structures used. For the 4 compartments, i.e. air, water, soil and sediment, the following mass amounts are predicted for the first structure: 0.01 %, 2.02 %, 29.10 % and 68.94 %, respectively. The corresponding half-lives in the different compartments are predicted as: 0.98 h, 900 h, 1800 h and 8100 h, respectively. The overall persistence time is predicted as 3080 h. The prediction results for the second representative structure are as followed: 0.02 % for air with a half-life of 0.54 h, 13.8 % in water (half-life: 1440 h), 86.2 % in soil (half-life: 2880 h) and 1.3E-4% (half-life: 13000 h) in sediment, respectively. The half-life in water, soil and sediment is given as 100000 h. The overall persistence time is 1640 h.