Amines, C11-14-branched alkyl, monohexyl and dihexyl phosphates

Endpoint summary

Additional information

Fish

Two studies on the short-term toxicity to fish are available, one with a coldwater fish (rainbow trout) and the other one with the warmwater zebra fish. Both studies were performed in accordance to OECD203, but have several shortcomings (no analytics perfomed, high amount of solvent used). However, results of both studies can be used to determine the toxicity to fish.

In the first study (1984) the 96-h acute toxicity to rainbow trout (Oncorhynchus mykiss) was assessed under static conditions.  The calculated and graphically determined 96-h LC50 based on mortality was 5.5 mg/L. The 96-h LC0, based on mortality, was 3.2 mg/L. 

In the second study the acute toxicity of the test item to the warm water fish zebra fish was determined under static conditions. The graphically determined 96-h LC50 based on mortality was 10.8 mg/L, the 96-h LC0 was graphically determined to be 5.8 mg/L.

Based on the results of the available studies the LC50 for fish was determined to be 5.5 mg/L.

Aquatic invertebrates

Only one reliable study on short-term toxicity on aquatic invertebrates is available. In the key study (2005) Daphnia magna were exposed to the test item for 48 h under static conditions. A nominal concentration of 1 mg/L WAF (water accommodated fraction) was applied as a limit test. The EC50 of Daphnia magna during 48 h exposure was higher then 1 mg/L WAF, indicating a low toxicity of the test organisms to the test item.

However, the EC50-value of > 1 mg/L was used as worst case consideration for the environmental risk assessment. 

One study on long term toxicity on aquatic invertebrates is available. A semi-static GLP-guideline study according to OECD 211 has been conducted (2014). The test substance is an UVCB substance. Additionally, due to the low water solubility water accomodated fractions (WAF) have been prepared according to guidance provided in OECD 23. Each test solution was prepared separately (differential loading) by directly adding test substance to test medium. As an additional water quality parameter, the content of total dissolved organic carbon was determined in the control and highest test concentration.

After 22 d significant effects on immobile young were observed at 10 mg/L; however there was no effect on reproduction (living young per adult) in this test group so the slight increase of immobile young is not considered a population relevant effect. Therefore NOEC and LOEC were determined ≥ 10 mg/L loading rate.

Total organic carbon analysis qualitatively demonstrated the presence of dissolved organic carbon originating from the test substance at the highest test concentration.

Algae

One reliable study on the toxicity to aquatic algae and cyanobacteria is available. In the key study (RCC, 2007) the EC50 for the green algae Pseudokirchneriella subcapitata based on growth rate was determined to be > 10 mg/L loading rate after exposure 72 h under static conditions indicating a low toxicity to algae to the test item. The ErC10 was determined to be 4.9 mg/L.

Micro-organisms

In a 3-hr acute toxicity study sewage sludge microorganisms were exposed to the test item. The IC50 value based on respiration rate was >100 mg/L after a 3 h contact time.