Registration Dossier

Environmental fate & pathways

Endpoint summary

Administrative data

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

TEGDB:

Biodegradability:

- Key study, reliability 1, OECD 301B - CO2 Evolution 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

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

 

These data demonstrate that all three 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 (all components)

Adsorption coefficient (Koc); 3981 (DPGDB)

 

All studies were performed according to international test guidelines and in compliance with GLP. 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 two of the components (DEGDB and DPGDB). In each test the positive control substance demonstrated rapid biodegradation (greater than 60% after 6/7 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%.  For TEGDB a CO2 Evolution Test according to OECD 301B has been performed and the substance has been shown to be also readily biodegradable.

 

No further testing is proposed or required.

DPGDB

Biodegradation

In the 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 the 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 oflog10Kocfor DEGDB of 3.2 was obtained (equivalent Koc= 1500) at 20°C (HLS 1999, VCL261/972408).  

TEGDB

Biodegradation

In the CO2 evolution test TEGDB was found to have degraded by 16% after 2 days, 62% after 7 days, and by 92% at the end of the 28 day biotic phase of the test (HLS 1998, VCL287/973177).

In this test, TEGDB met the criteria for ready biodegradability.

Transport and Distribution

A value of log10 Koc for TEGDB of 3.2 was obtained (equivalent Koc = 1400) at 20°C(HLS 1998, VCL261/972409).

Although as presented, DEGDB and TEGDB have the same log10Koc, rounding differences result in different values for Koc.

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, DEGDB or TEGDB 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

According to the adaptations found in column 2 of annex IX, the bioconcentration in aquatic species study can be waived if direct and indirect exposure to the aquatic environment is unlikely. This substance has no defined uses where direct application to the aquatic environment would occur, and because the substance is readily biodegradable, wastewater treatment would also make indirect exposure to the aquatic environment unlikely. 

 

QSAR estimates have been made for two components (DPGDB, DEGDB) of the reaction mass. Evidence of a low bioaccumulation potential is provided by these estimates, showing BCF values <200 L/kg for DPGDB and <100 L/kg for DEGDB, using a regression method based upon the experimental log Kow of 3.9 for DPGDB (HLS, 1999, VCL249/972399) and of 3.2 for DEGDB (HLS 1999, VCL261/972408). Using the Arnot-Gobas QSAR method the BCF/BAF values for all trophic levels are < 10 L/kg when biotransformation rates are utilized. From the similarity of its properties, TEGDB would be expected to behave in the same way. For these reasons, and for animal welfare reasons, it is believed that a bio-concentration study is not justified and is not proposed.