Oxydipropyl dibenzoate

Endpoint summary

Additional information

Short-term toxicity to fish

Studies were conducted to determine the acute toxicity of the test material DPGDB to freshwater fish (Rainbow Trout and fathead minnows). Studies were both species were conducted with the substance introduced using a water accommodated fraction (WAF) and by flow through. The studies were conducted according to EC, OECD, and US EPA test guidelines, and in compliance with GLP. The WAF studies suffered from low concentrations of the test substance being measured in the initial WAF solution and subsequent losses of the test substance. In addition, the results from the WAF tests with the two species showed no toxicity with one species and high toxicity with the other which was unexplainable. Because of the various problems with the two WAF tests, they are believed to be unreliable and have been disregarded. The flow through studies were well conducted exhibiting constant exposure levels throughout the studies and the results from both species were similar and in line with QSAR estimations. The results from the flow through studies are being used for the hazard determination and are presented below.

The 96 h LC50 value for DPGDB with fathead minnow was 3.7 mg/L. The "no-observed effect concentration" (NOEC) for DPGDB with fathead minnow was 1.2 mg/L (HLS 2000, VCL332/994962).

The 96 h LC50 value for DPGDB with rainbow trout was >3.0 mg/L. The "no-observed effect concentration" (NOEC) for DPGDB with rainbow trout was 3.0 mg/L (HLS 2000, VCL333/002268).

Those values are supported by the QSAR modelling (EPIsuite ECOSAR v1.00, 2009) with a value of 3.94mg/l.

Long term toxicity to fish

This study is proposed to be waived, based on the short-term testing results and the rapid biodegradability of the substance.

 

Short-term toxicity to aquatic invertebrates

An acute Daphnia Immobilisation study was performed to determine the acute toxicity to Daphnia of the test material dipropylene glycol dibenzoate (DPGDB) (HLS 2001, VCL 252/974221). The study was conducted according to EC, OECD, and US EPA test guidelines, and in compliance with GLP. The 48 hour EL50 (immobilisation value for DPGDB with Daphnia Magna) was determined to be 19.3 mg/L. The "no-observed effect loading rate" (NOELR) was 2.2 mg/L.

 

Long-term toxicity to aquatic invertebrates

A 21 -day Reproduction study with Daphnia magna was conducted. The most sensitive endpoints were reproduction (total living offspring per surviving female) and length. The 21-day No-Observed-Effect Concentration (NOEC) and Lowest-Observed-Effect Concentration (LOEC) were determined to be 40 and 100% of 100 mg/L WAF, respectively. Based on geometric mean measured concetrations the NOEC and LOEC values were 2.2 and 5.6 mg/L.

 

Toxicity to aquatic algae and cyanobacteria

An algal growth inhibition test was conducted to determine the effect on the growth of algae of the test material dipropylene glycol dibenzoate (DPGDB) (HLS 2001, VCL 253/974220). The study was conducted according to EC, OECD, and US EPA test guidelines, and in compliance with GLP. The EL50 (Area under the curve 72 h) was 1.1 mg/L and the EL50 (Growth rate 0 - 72 h) was 4.9 mg/L, while the EL50 (Area under the curve 96 h) was 0.95 mg/L and the EL50 (Growth rate 0 - 96 h) was 3.6 mg/L.

 

Toxicity to aquatic plants other than algae

No data available. No data required.

 

Toxicity to microorganisms

An activated sludge respiration inhibition test was conducted to determine the effect on sewage micro-organisms of the test material DPGDB (HLS 1998, VCL235/970385). The study was conducted in accordance with EC, OECD, and US EPA test guidelines, and in compliance with GLP. The EC20, EC50 and EC80 of the test material could not therefore be calculated but these must be greater than a nominal concentration of 100 mg/l, the highest tested level.

 

Toxicity to other microorganisms

No data available. No data required.

 

Conclusion

The acute toxicity to aquatic organisms was investigated in (i) freshwater fish (2

species), (ii) in Daphnia magna and (iii) in green algae, while chronic toxicity was evaluated in (iv) a 21 -day Daphnia magna reproduction study.

The results were as follows:

(i). The 96h LL50 to freshwater fish was determined to be 3.7 mg/L.

(ii). The 48 hour EL50 (EC50) immobilisation of Daphnia magna was determined to be 13.9 mg/L.

(iii). For algal growth inhibition, Selenastrum capricornutum, the EL50 (Area under the curve 72 h) was 1.1 mg/L and the EL50 (Growth rate 0 - 72 h) was 4.9 mg/L, while the EL50 (Area under the curve 96 h) was 0.95 mg/L and the EL50 (Growth rate 0 - 96 h) was 3.6 mg/L. The 72 -hr NOELR for growth rate was 1.0 mg/L.

(iv). In the chronic daphnid study, based on nominal concentrations and the most sensitive endpoints, reproduction (total living offspring per surviving female) and length, the 21-day No-Observed-Effect Concentration (NOEC) and Lowest-Observed-Effect Concentration (LOEC) were determined to be 40 and 100% of 100 mg/L WAF, respectively (2.2 and 5.6 mg/L as geometric mean measured concentrations, respectively).