Sucrose, glycerol and propane-1,2-diol, reaction products with C16-18(even numbered) fatty acids

Toxicity to aquatic algae and cyanobacteria

Description of key information

Under the conditions of the present study with Pseudokirchneriella subcapitata, the test substance reduced growth rate of this fresh water algae species significantly at nominally 10 mg/L and higher.
Yield was significantly inhibited at nominally 3.2 mg/L and higher.
The EC50 for growth rate reduction (EeC50: 0-72 h) was 16 mg/L with a 95% confidence interval ranging from 11 to 24 mg/L.
The EC50 for yield inhibition (EyC50: 0-72 h) was 6.0 mg/L with a 95% confidence interval ranging from 2.6 to 13 mg/L.
The NOEC for growth rate reduction and yield inhibition was 3.2 and 1.0 mg/L, respectively.

Key value for chemical safety assessment

EC50 for freshwater algae:

16 mg/L

EC10 or NOEC for freshwater algae:

3.2 mg/L

Additional information

Since no studies investigating the toxicity of Sucrose, glycerol and propane-1,2-diol, reaction products with C16-18(even numbered) fatty acids, to aquatic algae are available, in accordance to Regulation (EC) No 1907/2006 Annex XI, 1.5 a read-across to the structurally related source substance Sucrose and glycerol, reaction products with C12-18, C18unsatd. fatty acids (List No. 938-754-6) was conducted. The read-across substance is representative to evaluate the short-term toxicity of Sucrose, glycerol and propane-1,2-diol, reaction products with C16-18(even numbered) fatty acids (target substance) to aquatic invertebrates.
The target substance is a UVCB substance specified by the reaction product of mainly C16 and C18 linear fatty acids with sucrose, glycerol and propane-1,2-diol. The source substance Sucrose and glycerol, reaction products with C12-18, C18unsatd. fatty acids (List No. 938-754-6) is an UVCB substance resulting by the reaction of a fatty acid mixture with glycerol and sucrose. A detailed analogue approach justification is provided in the technical dossier (see IUCLID Section 13). The source substance has a similar structure and is suitable for read across to the target substance. In this case of read-across, the best suited (highest degree of structural similarity, nearest physico-chemical properties) read-across substance was used for the assessment.
This read-across is justified in detail in the overall summary (IUCLID Section 6.1) and within the analogue justification in IUCLID Section 13.

In a 72 hour acute toxicity study, the cultures of Pseudokirchneriella subcapitata, strain NIVA CHL 1 were exposed to the source substance Sucroglyceride C12-18, C18unsatd.at nominal concentrations of 0 (control),1.0, 3.2, 10, 32 and 100 mg/L under static conditions in accordance with the OECD guideline 201. 

The EC50 for growth rate reduction (ErC50: 0-72 h) was 16 mg/L with a 95% confidence interval ranging from 11 to 24 mg/L.

The EC50 for yield inhibition (EyC50: 0-72 h) was 6.0 mg/L with a 95% confidence interval ranging from 2.6 to 13 mg/L.

The NOEC for growth rate reduction and yield inhibition was 3.2 and 1.0 mg/L, respectively.

This toxicity study is classified as acceptable and satisfies the guideline requirements for freshwater Alga and Cyanobacteria, Growth Inhibition Test.