3,4,5-trihydroxybenzoic acid

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

Remarks:

see deviations from guideline; however the assay evidenced significant toxicity and therefore acts as worst-case data enabling to classify the test item

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Deviations:

yes

Remarks:

no negative control; missing details on test medium and oxygen; hardness 100 mg/L CaCO3 vs. 140-250 mg/L recommended; pH went below 6, possibly leading to pH-induced toxicity

Principles of method if other than guideline:

Daphnia magna neonates (<24h) from 2–3-week-old mothers were placed in a 50 ml glass beaker containing 40 ml of a test solution.
All experiments for exposure were made in four replcates and performed at 21 ± 0.3 °C under 16 h light: 8 h dark photoperiod.
Immobility was used as the endpoint for determining acute toxicity; the daphnids showing no movement within 15 s after gentle stirring were defined to be immobile.
After 24 and 48 h, the number of immobile daphnids was recorded to determine the concentration able to achieve 50% immobilization and it was indicated as EC50.
The EC50 values were calculated by Probit analyses (USEPA, 1993), based on nominal concentrations.

GLP compliance:

not specified

Analytical monitoring:

yes

Test organisms (species):

Daphnia magna

Details on test organisms:

Neonates (<24h)

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Hardness:

100 mg CaCO3 / L

Test temperature:

21 ± 0.3°C

pH:

Initial pH 7.45 ± 0.05. No neutralisation during the assay.

Nominal and measured concentrations:

Tested concentration levels: 0.0625 to 1.0 mmol/L

Reference substance (positive control):

no

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

19.1 mg/L

Basis for effect:

mobility

Remarks on result:

other: 95% CI: 16.0-22.7 mg/L

Details on results:

The solution pH decreased below 6 at concentrations over 1 mmol/L 1 of benzoic acids when dissolved in the test medium employed, and daphnids exposed to these solutions showed 100% immobility. Consequently, the toxic effects of benzoic acids were not related to the exposed concentrations alone, under the non-neutralized condition.

Validity criteria fulfilled:

not applicable

Remarks:

no negative control and no data on dissolved oxygen

Conclusions:

Daphnia EC50-48h of the test item is 19.1 (95% CI: 16.0-22.7) mg/L.

Description of key information

Daphnia EC50-48h of the test item is 19.1 (95% CI: 16.0-22.7) mg/L.

Based on these endpoints, gallic acid is not classified for aquatic hazards.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

19.1 mg/L