Decene, hydroformylation products

Sediment toxicity

Description of key information

  In accordance with REACH Annex IX, the requirement for toxicity sediment organisms is waived on the basis of lack of direct or indirect exposure to sediment organisms, ready biodegradability in water and low toxicity to aquatic life. No reliable predicted or measured toxicity data to sediment organisms are available for Alchisor CAL 111.

Additional information

Alchisor CAL 111 is thetrade name for decene, hydroformylation products, high boiling. As defined in the ‘Read-Across Justification Document’, data provided for the analogue substance Alchisor CAL 123 is representative of Alchisor CAL 111 and suitable for assessment purpose.

In accordance with REACH Annex X, the requirement for studies of the effects on sediment organisms is waived on the basis of unlikely direct and indirect exposure of the sediment compartment. In addition, other evidence presented in this dossier on the substance’s analogue (Alchisor CAL 123) ready biodegradability and low toxicity to aquatic organisms further support the waiver. No reliable predicted or measured toxicity to sediment organisms data are available for Alchisor CAL 123 or Alchisor CAL 111.

Exposure to Sediment

It is unlikely that sediment organisms will be exposed to Alchisor CAL 111 as there is no intended use involving the direct application of Alchisor CAL 111 to watercourses and their sediments. In addition, it is unlikely that indirect exposure will occur, via the water column, as Alchisor CAL 111 is deemed readily biodegradable. 

Biodegradation

Alchisor CAL 123 has been shown in the reliable (Klimisch 1) study by Schaefer and Matthews (2010) to be readily biodegradable in water. The test substance biodegraded to an extent of 87.7% after 28 days and although the biodegradation rate just missed the 10-day window threshold, this aspect of the test is not applicable to mixtures where different components of the mixture can biodegrade preferentially (reference TG 103C). It is assumed that Alchisor CAL 123 will readily biodegrade in water and be unavailable for uptake by sediment organisms.

Toxicity to Aquatic Organisms

The toxicity of the test substance analogue, Alchisor CAL 123, to aquatic organisms is very low based on the evidence presented in this dossier. The lowest measured toxicity was based on an algal test where the NOEL based on algal growth was 25 mg/L. Acute toxicity to invertebrates and fish was >100 mg/L based on 50% mortality. In addition, because the substance has been deemed readily biodegradable, it is unlikely that sediment organisms would encounter long-term exposure to the substance. Using this evidence, it is reasonable to assume that Alchisor CAL 123 represents a low hazard and is not considered to be toxic (in PBT terms) to aquatic life.

In summary, the data requirement for toxicity to sediment organisms is waived on the evidence of lack of direct or indirect exposure to sediment organisms, ready biodegradability in water and the low toxicity to aquatic organisms. For completeness, PNECs were calculated using the partitioning coefficient method. PNECsediment freshwater is 44,176 mg/kg ww (or 9,603 mg/kg dry wt) and the PNECsediment marine is 441.7 mg/kg ww (or 96 mg/kg dry wt).