Sodium chloride

Toxicity to soil macroorganisms except arthropods

Description of key information

The mean 14-day LC50 for three experiments conducted with the earthworm, E. fetida was 3,296 mg NaCl/kg soil dw.  The 10-week NOEC (based on mortality) was 3,507 mg NaCl/kg soil for the earthworm, E. fetida.

Key value for chemical safety assessment

Short-term EC50 or LC50 for soil macroorganisms:

3 296 mg/kg soil dw

Long-term EC10, LC10 or NOEC for soil macroorganisms:

3 507 mg/kg soil dw

Additional information

Three acute and one chronic toxicity study with soil macroorganism were availble for sodium chloride. All four studies were assigned a Klimish score of 2. In the chronic study, the earthworm, Eisenia fetida, was exposed to seven concentrations of NaCl in the soil (and control soil) for 10 weeks, and mortality and reproduction were assessed. The NOEC (based on mortality) was 3507 mg/kg soil. All concentrations of sodium chloride used in the chronic study decreased earthworm reproduction, and the LOEC based on reproduction was 1169 mg/kg soil ww. In one acute toxicity study with the earthworm, E. fetida, the mean LC50 for NaCl was determined to be 3,296 mg/kg dw in a series of 14-day soil exposure studies. In another study with the same species, the 48 -hour LC50 for sodium chloride ranged from 100 -1000 µg/cm2. In another toxicity study with sodium chloride, avoidance behavior of two worm species (E. fetida and A. caliginosa) were studied and the EC50 values (based on avoidance behavior toward contaminated soil) for E. fetida and A. caliginosa were 1164 and 664 mg/kg soil dw, respectively. Since avoidance behavior is a less definitive endpoint and there is more uncertainty associated with the mortality endpoint, the LC50 value of 3,296 mg/kg soil dw was selected as the key acute value for this endpoint.