Citric acid

Short-term toxicity to fish

Link to relevant study record(s)

Reference

Endpoint:

short-term toxicity to fish

Type of information:

experimental study

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

test procedure in accordance with national standard methods with acceptable restrictions

Remarks:

The study was conducted according to an appropriate national standard method. It was not compliant with GLP and no analytical monitoring was carried out. Restrictions in reporting.

Qualifier:

according to guideline

Guideline:

other: German standard methods for water, wastewater and sludge analysis. L 15: fish test (determination of the effect of water constituents in fish

Deviations:

not specified

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

Deviations:

not applicable

GLP compliance:

no

Analytical monitoring:

no

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)

- Method: direct addition of test item to achieve nominal concentrations

- Evidence of undissolved material (e.g. precipitate, surface film, etc): not reported

Test organisms (species):

Leuciscus idus melanotus

Details on test organisms:

TEST ORGANISM

- Common name: golden orfe

- Source: fish farm, details not reported

- Length at study initiation (range): 5-7 cm

- Weight at study initiation (mean, SD): 1.5 + / - 0.3 g

- Feeding during test: no


ACCLIMATION

- Acclimation period: 3 days

- Acclimation conditions (same as test or not): same as test

- Type and amount of food: 10 to 20 mg of dried food for aquariums

- Feeding frequency: 3 times a week

- Health during acclimation (any mortality observed): <1%

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Hardness:

15 + / - 3 ° dH

Test temperature:

20 +/- 1 degC

pH:

ca. 7-8

Dissolved oxygen:

<5 mg/L

Nominal and measured concentrations:

Not reported

Details on test conditions:

TEST SYSTEM

- Test vessel:

- Material, size, fill volume: 17 L glass aquarium, 24 cm (h) x 32 cm (w) x 22 cm (d), filled with 10 L test medium

- Aeration: yes, through glass capillaries

- Renewal rate of test solution (frequency/flow rate): not renewed

- No. of organisms per vessel: 10

- No. of vessels per concentration (replicates): not reported

- No. of vessels per control (replicates): not reported

- Biomass loading rate: max 5 fish / L


TEST MEDIUM / WATER PARAMETERS

- Source/preparation of dilution water: dechlorinated tap water

- Alkalinity: 0.7-0.9 mmol/L

- Intervals of water quality measurement: not reported


OTHER TEST CONDITIONS

- Adjustment of pH: if required. To be adjusted with 1 M sulfuric acid if pH too high, and to be adjusted with 1 M bicarbonate solution

- Photoperiod: not reported


EFFECT PARAMETERS MEASURED (with observation intervals if applicable): mortality observed every 24 h


TEST CONCENTRATIONS

- Spacing factor for test concentrations: not reported

Reference substance (positive control):

not specified

Key result

Duration:

48 h

Dose descriptor:

LC50

Effect conc.:

440 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Remarks on result:

other: lab: WaBoLu

Key result

Duration:

48 h

Dose descriptor:

LC50

Effect conc.:

760 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Remarks on result:

other: lab: LWA NW

Duration:

48 h

Dose descriptor:

LC0

Effect conc.:

620 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Remarks on result:

other: lab: LWA NW

Duration:

48 h

Dose descriptor:

LC100

Effect conc.:

800 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Remarks on result:

other: lab: LWA NW

Duration:

48 h

Dose descriptor:

LC0

Effect conc.:

200 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Remarks on result:

other: lab: WaBoLu

Duration:

48 h

Dose descriptor:

LC100

Effect conc.:

600 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Remarks on result:

other: lab: WaBoLu

Reported statistics and error estimates:

The LC50 value has been determined graphically.

Validity criteria fulfilled:

not specified

Conclusions:

Two 48 h LC50 values corresponding to 440 mg/L and 760 mg/L have been determined in two laboratories for the effects of citric acid on mortality of the freshwater fish Leuciscus idus melanotus.

Description of key information

Short-term toxicity to fish: 48h LC₅₀ 440 mg/L (nominal) (equivalent to OECD 203), Leuciscus idus melanotus (Juhnke and Ludemann 1978, rel. 2)

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Effect concentration:

440 mg/L

Additional information

Two 48h LC₅₀ values corresponding to 440 mg/L and 760 mg/L have been determined for the effects of citric acid on mortality of the freshwater fish Leuciscus idus melanotus (Juhnke and Ludemann 1978, reliability 2). It is not clear whether the test medium was neutralised; the OECD guideline followed suggests adjusting the pH to ca. 7 when needed but the OECD SIDS on citric acid (2001) states that the test media was not neutralised. In spite of this uncertainty the study has been considered as part of a weight of evidence approach.

An LC₅₀ >100-1000 mg/L is reported in a study by Terhaar et al. (1972), in which Pimephales promelas were exposed up to 1000 mg/L citric acid for 96 hours. No mortality was observed with fish exposed at 100 mg/L after 96h, while 100% mortality was achieved at the 1000 mg/L concentration. While the study is not said to have followed a guideline nor in compliance with GLP, the study methods are well documented and is considered to be reliability 2. This study has been considered in the weight of evidence approach.

Two studies with reliability 4 (due to insufficient reporting) support the conclusion that citric acid has low toxicity to fish in short-term exposures – i.e. LC₅₀ values indicating effects at >100 mg/L.

In addition, a Safepharm 2006 study is reported in the CLH consultation on citric acid, indicating a 96h LC₅₀ value >100 mg/L, despite the pH of the test medium dropping below pH 6. Access to the report has not been purchased, for details please refer to the CLH consultation here https://echa.europa.eu/documents/10162/c721decb-298f-92a3-b425-55cbf9c6cc9b [accessed January 2019].