Decahydronaphthalene

Short-term toxicity to aquatic invertebrates

Description of key information

The 48-hour acute toxicity of the test item to the freshwater planktonic crustacean, Daphnia magna, was determined in accordance with the requirements of OECD Chemicals Testing Guideline No. 202 (adopted April 13 2004). Based on the results of a range-finding test the definitive test was conducted at nominal concentrations of 6.25, 12.5, 25, 50 and 100% saturated solution. The test was conducted under semi-static test conditions. Analysis of the test media samples was conducted on fresh media at 0 and 24 hours and on corresponding old media at 24 and 48 hours. Concentrations above the LOQ of the analytical method (assessed as 0.1 mg/L)  were not determined at nominal concentrations of 25% saturated solution and below, however, measured concentrations were recovered at nominal concentrations of 50 and 100% saturated solutions. Given the decline in measured concentration observed over each 24-hour exposure period, the results have been reported in terms of time-weighted mean measured concentrations. These were calculated to be 0.163 and 0.366 mg/L for the 50 and 100% saturated solution test concentrations, respectively. Based on time-weighted mean measured concentrations, the 48-hour EC₅₀value was determined to be 0.286 mg/L. The validity criteria for control immobility (≤10%) and dissolved oxygen (≥3 mg/L) were both satisfied. The test is therefore considered valid.

In another study the 96-hour acute toxicity of the test substance against the survival of the marine crustacean, Mysidopsis bahia, was determined. The study was conducted in accordance with the requirements of Ecological Effects Test Guideline OPPTS 850.1035 Mysid Acute Toxicity Test (April 1996). Due to the physiochemical properties of the test substance saturated solutions with a loading of 100 mg/L were prepared. Four replicates per control and treatment level each containing 5 organisms were exposed under semi static conditions to different concentrations of the test item (Control, 3.125, 6.25, 12.5, 25 and 50 % Saturated Solution of a 100 mg/L Loading rate for 96 hours. Based on geometric mean measured concentrations, the LC50 values with corresponding 95% confidence intervals were calculated as 0.0372 mg/L (0.0339 - 0.0385 mg/L) for 96 hours and 0.0500 mg/L (0.0463 - 0.0507 mg/L) for 48 hours. The No-Observed-Effect Concentration (NOEC) was determined as 0.0265 mg/L.

 

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

0.286 mg/L

Marine water invertebrates

Marine water invertebrates

Effect concentration:

0.037 mg/L

Additional information

The toxicity to aquatic invertebrates was investigated in several studies. During the evaluation procedure in 2014 ECHA requested new acute and chronic data with invertebrates.

The 48-hour acute toxicity of the test item to the freshwater planktonic crustacean, Daphnia magna, was determined in accordance with the requirements of OECD Chemicals Testing Guideline No. 202 Daphnia sp. Acute Immobilisation Test (adopted April 13 2004). Based on time-weighted mean measured concentrations, the 48-hour EC₅₀value was determined to be 0.286 mg/L.

 

In other studies with aquatic invertebrates EC50 values above 1 mg/L were observed. The acute toxicity to aquatic invertebrates (Daphnia pulex) was determined in a static test conducted according to Am. Soc. Test Mater. (1980) and U.S. EPA (1975). A series of 5 concentrations with 10 organisms each was tested for 48 h and the EC50 value was determined to be 2.5 mg/L. The effects of decahydronaphthalene on Daphnia magna were studied by Hüls AG, Marl (1992) in a 48-h acute toxicity test at 5 concentration levels up to 2.9 mg/L. Due to deficiencies these tests were declared as "not reliable" during the evaluation process.