Registration Dossier

Environmental fate & pathways

Endpoint summary

Administrative data

Description of key information

Additional information

B-TTEGME is a mixture of three borated methyl glycol esters which differ solely by the length of their "-CH2-CH2 -O-" (glycol ether) side chains (homologues). Its major components are B-TEGME (50%, with three glycol moieties per side chain) and B-TetraEGME (40%, with four glycol moieties per side chain). B-PentaEGME (five glycol moieties per side chain) contributes 10% to B-TTEGME. Biodegradation of B-TTEGME was reported in a OECD 302 A test (Shell 1999), which demonstrated that average 95% of the test material - containing 44% B-TTEGME - was degraded within 3 days of exposure (key study). Based on the criteria of the guideline, the test material is considered ultimately biodegradable.

Although the test design allows the assessment of inherent biodegradability, the rapid biodegradation (95% within 3 days) using non-adapted inoculum suggests the test material, including the three borated glycol ester homologues of B-TEGME, can be regarded as readily biodegradable.

Ready biodegradation of B-TTEGME is supported by the finding that one of its major homologue components B-TEGME (50% of B-TTEGME) is readily biodegradable. B-TEGME (88% pure) was investigated under GLP in a valid OECD 301A study (BASF 1999). The results show that B-TEGME is readily biodegradable. Two further studies are available which support the finding of biodegradation (Shell 1986) of borated glycol esters. These studies were performed with brake fluid DOT4, a mixture of methyl and butyl borated glycol esters,

i.e., 35% B-TTEGME (three methyl borated glycol ester homologues), 48% of their respective polyethylene glycol ethers, 13% butyl glycol ethers and 3% additives (not specified).

It is reported that degradation was still proceeding steadily at the end of the Modified Sturm test. Degradation observed in these two tests may reflect partial or complete degradation of a number of components of brake fluid DOT4. Since B-TTEGME is readily biodegradable, simulation tests on degradation in water, soil, and sediment are not required as B-TTEGME is not expected to persist in the environment.