Registration Dossier

Environmental fate & pathways

Endpoint summary

Administrative data

Description of key information

The bioaccumulation of substances can pose a risk of chronic toxicity to organisms due to the accumulation of these substances in their tissues or through biomagnification up the food chain. Bioaccumulation potential is typically quantified by determining either a bioconcentration factor (BCF), a bioaccumulation factor (BAF) or, for soil organisms, a Biota to Soil Accumulation Factor (BSAF).

 

However, although well understood for organic substances, the determination of BCF, BAF or BSAF may be of little use in understanding the hazard of inorganic substances. Unlike organic substances which may be taken up by passive diffusion across cell walls metals are generally taken up by specific active transport mechanisms and so are regulated. Some metals are essential for growth, so may be highly accumulated when present at low concentrations but accumulated at a lower rate when present at higher concentrations. 

Additional information

Secondary poisoning

 

The REACH guidance for Section 4.4 calls for a summary of bioaccumulation and biomagnification factors, and interpretation of the potential to bioaccumulate in the food chain. Bioaccumulation in the food chain is interpreted as increasing accumulation in successive trophic levels, which is analogous to biomagnification.

 

Antimony bioaccumulation in aquatic and terrestrial food chains is presented in Sections 5.3.1 and 5.3.2 of the IUCLID dossier, respectively, and discussed in the summary record. Bioaccumulation of antimony by both aquatic and terrestrial organisms is low. A BCF of 40 has been determined for aquatic organisms and a BSAF of 1 for earthworms. As antimony is not bioaccumulative it will also not bioaccumulate in the food chain (biomagnify). Culioli et al (2009) found indeed that bioaccumulation factors, defined as ratios of metalloid concentrations between consumers and diets, diminished with higher trophic levels in and aquatic ecosystem.

 

This was also the conclusion reached in another recent regulatory review (Environment Canada, 2010). Based on this, an assessment of secondary poisoning is not required.