Reaction mass of oxydiethylene dibenzoate and oxydipropyl dibenzoate

Endpoint summary

Description of key information

DEGDB:

Biodegradability:

- Key study, reliability 1, OECD 301B - Modified stturm test - readily biodegradable

- Supporting study, reliability 1, OECD 301D - Closed Bottle Test - not readily biodegradable

- Supporting study, reliability 1, ISO Method 11734 - Anaerobix Biodegradability of Organic Chemicals - Ultimately biodegradable under anaerobic conditions

- Supporting study, reliability 2, OECD 301A - Ready Biodegradability: DOC Die Away Test - readily biodegradable

Bioaccumulation:

- Supporting study, reliability 2, QSAR-estimation - EPIWIN (BCFBAF v 3.00) - BCF value <100 L/kg

DPGDB:

Biodegradability:

- Key study, reliability 1, OECD 301B - Modified sturm test - readily biodegradable

- Supporting study, reliability 1, OECD 301D - Closed Bottle Test - not readily biodegradable

- Supporting study, reliability 1, ISO Method 11734 - Anaerobix Biodegradability of Organic Chemicals - Ultimately biodegradable under anaerobic conditions

- Supporting study, reliability 2, OECD 301A - Ready Biodegradability: DOC Die Away Test - readily biodegradable

Bioaccumulation:

- Supporting study, reliability 2, QSAR-estimation - EPIWIN (BCFBAF v 3.00) - BCF value <200 L/kg

Reaction Mass of DEGDB and DPGDB:

Adsorption / desorption

- Key study, reliability 1, EU Method C.19 (Estimation of the Adsorption Coefficient (KOC) on Soil and Sewage Sludge Using High Performance Luquid Chromatography (HPLC)) - log Koc = 2 .94 - 3.52 at 30 °C

Additional information

This substance is a reaction mass of dipropylene glycol dibenzoate (DPGDB) and diethylene glycol dibenzoate (DEGDB). No testing has been performed on the reaction mass itself but data are available for DPGDB and DEGDB. The most sensitive endpoint result obtained for these components has been used to evaluate hazard.

 These data demonstrate that both components of the reaction mass have similar environmental profiles, being readily biodegradable, of moderate adsorption and predicted to be not bioaccumulative.  

 

The key values used in the chemical safety assessment are:

Biodegradation in water; readily biodegradable (both components)

Adsorption coefficient (Koc); 3981 (DPGDB)

 

All studies were performed according to international test guidelines and in compliance with GLP unless stated. They are presented below, by component. The key value for hazard evaluation is highlighted. Where no data exist an overall statement that applies to the reaction mass has been made.

Modified Sturm ready biodegradation tests were performed on each component. In each test the positive control substance demonstrated rapid biodegradation (greater than 60% after 6 days) confirming the inoculum was viable and that the test was valid. Substances are considered to be readily degradable in this test if CO2 production is equal to or greater than 60% of the theoretical value within ten days of the level achieving 10%.

No further testing is proposed or required.

DPGDB

Biodegradation

In a modified Sturm test DPGDB was found to have degraded by 6% after 2 days, 62% after 12 days, and by 85% at the end of the 28 day biotic phase of the test (HLS 1998, VCL236/972256). In this test, DPGDB met the criteria for ready biodegradability.

 

Transport and distribution

A value of log10Koc for DPGDB of 3.6 was obtained (equivalent Koc =3981) (HLS 1999, VCL249/972399).

DEGDB

Biodegradation

In a modified Sturm test DEGDB was found to have degraded by 17% after 2 days, 71% after 10 days, and by 93% at the end of the 28 day biotic phase of the test(HLS 1998, VCL246/972257). In this test, DEGDB met the criteria for ready biodegradability.

 

Transport and distribution

A value of log10Kocfor DEGDB of 3.2 was obtained (equivalent K_oc= 1500) at 20°C (HLS 1999, VCL261/972408).

 

OTHER ENDPOINTS

 

Stability

In accordance with REACH Annex VIII column 2, a study did not need to be conducted on the reaction mass as its components DPDGB or DEGDB are readily biodegradable.

Biodegradation in water and sediment

In accordance with the adaptations found in column 2 of Annex IX, simulation studies of biodegradation in water and sediments are waived due to the demonstrated ready biodegradation of the components of the substance.

Biodegradation in soil

In accordance with the adaptations found in column 2 of Annex IX, simulation studies of biodegradation in soils are waived due to the demonstrated ready biodegradation of the components of the substance. 

Bioaccumulation

This reaction mass has no defined uses where direct application to the aquatic environment would occur, and because the components of the reaction mass are readily biodegradable, wastewater treatment would also make indirect exposure to the aquatic environment unlikely. In addition, evidence of a low bioaccumulation potential is provided by QSAR estimates for the components. Using a regression method based upon the experimental log Kow value of 3.9 for DPDGB (HLS 1998, VCL249/972399) and 3.2 for DEGDB (HLS 1999, VCL261/972408), BCF values <200 L/kg and <100 L/kg, respectively are obtained. Using the Arnot-Gobas QSAR method the BCF/BAF values for all trophic levels are < 10 L/kg for both components when biotransformation rates are utilized. For these reasons, and for animal welfare reasons, it is believed that a bioconcentration study is not justified and is not proposed.