Reaction mass of dodecyltrimethylammonium bromide and tetradonium bromide

Biodegradation in water: screening tests

Description of key information

By using read across to structural alike substances, reaction mass of C12 trimethylammonium bromide and C14 trimethylammonium bromide is considered as readily biodegradable. Experimental data show that alkyl trimethylammonium halides are readily biodegradable under conditions where the substances do not exert toxicity to the microorganisms.

Key value for chemical safety assessment

Biodegradation in water:

readily biodegradable

Additional information

In a read-across approach, data on cetrimonium chloride/bromide and tetradonium bromide are included to support the evidence on the biodegradability of the substance: reaction mass of C12 trimethyl ammonium bromide and C14 trimethylammonium bromide. Read across between homologues of this type of substances can be done, as the degradability is determined by the alkyl structure and not by the counter ion. The biodegradability decreases with the length of the alkyl chain (according to studies by Garcia et al, 2001 and Yamane et al 2008), thus the biodegradability of C12 and C14 trimethylammonium bromide can be described by the biodegradability of the cetrimonium halides (C16).

Experimental data show that tetradonium bromide is readily biodegradable at conditions where the substance does not exert toxicity to the microorganisms.

Studies on cetrimonium chloride indicate that the substance is biodegradable, but not necessarily passing the criteria for readily biodegradability (FeF, 1993; Madsen et al, 2001; van Ginkel, 1996). This is especially observed when tested at concentrations above a certain level approximately 10-20 mg/L, which is considered to have a toxic effect on the microorganisms in the test system. When toxicity has been removed by the addition of silica gel or SIO2 to the test system, cetrimonium chloride has proven to pass the criteria for readily biodegradability (van Ginkel, 2004; OECD, 1996). When silica or SiO2 particles are present in the test system, the substance will enter equilibrium between adsorbed and dissolved phase. When the dissolved part of the substance biodegrades, the substance is gradually released from the adsorbed phase, and a low concentration not exerting toxicity is maintained in the test system.

Supporting studies with tetradonium bromide show that tetradonium bromide passed the criteria for ready biodegradation at 5 mg/L (Garcia et al, 2001). Note on the weight of evidence approach taken on the biodegradability of tha alkyl trimethylammonium bromide is attached the endpoint summary.