Benzene, C10-13-alkyl derivs.

Short-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Qualifier:

according to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

GLP compliance:

yes

Analytical monitoring:

yes

Details on sampling:

no information

Vehicle:

no

Details on test solutions:

A test solutions was prepared to reach the solubility concentration (0.041 mg/L), without using solvent.

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Source: Laboratory bred
- Age at study initiation: ≤ 24 hrs

Test type:

not specified

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Test temperature:

20°C

Conductivity:

- 0.2 g/L NaHCO3
- 0.224 g/L CaCl2
- 0.026 g/L K2SO4

Nominal and measured concentrations:

Nominal concentration: 0, 12.5%, 25%, 50%, 75% and 100% saturated (0.041 mg/L)

Details on test conditions:

TEST SYSTEM
- No. of organisms per vessel: 5
- No. of vessels per concentration: 4
- No. of vessels per control: 4

EFFECT PARAMETERS MEASURED: Immobilization

Reference substance (positive control):

no

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 0.041 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: > water solubility

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

0.041 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: > water solubility

Details on results:

No dose-response increase in the number of immobilized daphnids was observed. In addition, no significant increase in immobilization over controls was observed. An overview of the result is provided in Table 1 in "Any other information on results incl. tables".

Table 1. Immobilized daphnids at 48 hrs – LAB

Concentration	1	2	3	4
Control	0	1	0	0
100% (Saturated)	0	1	0	0
75%	1	0	0	1
50%	1	0	0	0
25%	0	1	0	0
12.5%	0	0	0	0

Validity criteria fulfilled:

yes

Conclusions:

Based on the findings, the 48-hr EC50 for daphnids was determined to be > 0.041 mg/L.

Executive summary:

This study determined the short-term toxicity of linear alkyl benzenes to Daphnia magna. The study was conducted according to EU method C.2 guideline and compliance with GLP. Daphnids were exposed to concentrations of 0, 12.5%, 25%, 50%, 75%, and 100% saturated test solution for 48 hrs. At the end of this period, the daphnids were observed for mobility. Though immobilized daphnids were seen at 4 test concentrations, there was no dose-related increase in immobilization, nor was the number of immobilized daphnids significantly increased over negative controls. Based on the findings, the 48-h EC50 was determined to be > 0.041 mg/L. This concentration is greater than the water solubility for the test substance.

Description of key information

A 48-hour short-term toxicity test of the test subtsance to freshwater invertebrate (Daphnia magna) was conducted according to EU method C.2. The LC50 based on mortality was determinded to be > 0.041 mg/L.

Additional information

The key study determined the short-term toxicity of LAB to Daphnia magna. A test solution was prepared, without use of solvent, to reach the solubility concentration (0.041 mg/L). Daphnids were then exposed to concentrations of 0, 12.5%, 25%, 50%, 75%, and 100% of the saturated test solution for 48 hours. At the end of this period, the daphnids were observed for mobility. Though immobilized daphnids were seen at four test concentrations, there was no dose-responsive increase in immobilization, nor was the number of immobilized daphnids significantly increased over the negative controls. Therefore, the 48-hr EC50 is > 0.041 mg/L (> 41 µg/L), which is greater than the limits of water solubility for the test substance.