Lactic acid

Long-term toxicity to fish

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

fish, juvenile growth test

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

disregarded due to major methodological deficiencies

Justification for type of information:

For details and justification of read-across please refer to the read-across report attached to IUCLID section 13.

Reason / purpose for cross-reference:

read-across source

Key result

Duration:

90 d

Dose descriptor:

LOEC

Effect conc.:

2.18 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

weight

Validity criteria fulfilled:

no

Conclusions:

Lactic acid LOEC ca. 2.18 mg/L

Executive summary:

The comparative toxicity of lactic acid, acetic acid, and benzoic acid to tilapia (Oreochromis mossambicus), cladoceran crustacean (Moina micrura), and oligochaete worm (Branchiura sowerbyi) were determined using static bioassay tests. Worms were found most sensitive to all the acids whereas the cladoceran was found most resistant to lactic acid and the fish most resistant to acetic acid and benzoic acid. The 96h LC50 values of lactic acid, acetic acid, and benzoic acid, were, respectively, 257.73, 272.87, and 276.74 mg/L for O. mossambicus; 329.12, 163.72, and 71.65 mg/L for M. micrura and 50.82, 14.90, and 39.47 mg/L for B. sowerbyi. Tilapia lost appetite at sub-lethal concentrations as low as 2.18 mg/L lactic acid, 1.26 mg/L acetic acid, and 13.84 mg/L of benzoic acid. Growth and reproduction of the fish were affected following 90-day chronic exposure to sub-lethal concentrations of the acids. Minimum effective concentrations of the acids that significantly reduced food conversion efficiency (FeE), percent increase of weight, specific growth rate, yield and fecundity of the fish were 2.18, 1,47, and 3.95 mg/L of lactic acid, acetic acid, and benzoic acid, respectively. Effects of acetic add and benzoic acid on FCE, weight increase, and yield were not significantly different from each other whereas lactic acid produced different effects from acetic acid as well as benzoic acid. Mean values of dissolved oxygen, primary productivity, and plankton populations of the test medium significantly reduced from control at 16.94 mg/L lactic acid, 16.79 mg/L acetic acid, and 13.84 mg/L benzoic acid.

This study is disregarded due to major methodological deficiencies.

Reference 2

Endpoint:

fish life cycle toxicity

Data waiving:

study scientifically not necessary / other information available

Justification for data waiving:

other:

Justification for type of information:

Lactic acid is a ubiquitous and essential molecule of life. As such, testing for chronic toxicity is not warranted. Moreover, since any effects by lactic acid observed in short-term aquatic toxicity tests can be attributed to pH shifts it can be concluded that the substance does not exert significant effects on environmental organisms that result in identification of a hazard. Accordingly, the chemical safety assessment does not indicate the need to further investigate environmental toxicity by means of long-term studies.

Description of key information

The 90-day LOEC for Tilapia is 2.18 mg/L, due to pH effects. The study is considered to be unreliable. Overall, a lactate-related hazard regarding long-term toxicity to fish is not identified.

According to REACH Annex IX, column 2, long-term toxicity testing shall be considered if the chemical safety assessment according to Annex I indicates the need to investigate further the effects on aquatic organisms. Since any effects by L-(+)-lactic acid observed in short-term aquatic toxicity tests can be attributed to pH shifts it can be concluded that the substance does not exert significant effects on environmental organisms that result in identification of a hazard. Accordingly, the chemical safety assessment does not indicate the need to further investigate environmental toxicity by means of long-term studies.