Chlorhexidine dihydrochloride

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:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Qualifier:

according to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

Deviations:

no

GLP compliance:

yes

Analytical monitoring:

no

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: stock solutions prepared (180 mg / 10 mL DMSO) and further diluted with DMSO. 150 μg DMSO solution mixed with 1.5 L dilution water

Test organisms (species):

Danio rerio (previous name: Brachydanio rerio)

Details on test organisms:

TEST ORGANISM
- Source: Commercial hatchery M.B. Ruysbroek B.V. (Noordvliet 159, Maassluis)
- Length at study initiation: 2.1+/- 0.2 cm
- Weight at study initiation: 0.09 +/- 0.02 g
- Feeding during test: no

Test type:

semi-static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

96 h

Hardness:

ca. 210 mg CaCO3/L

Test temperature:

24-26 °C

pH:

7.5 - 8.2

Dissolved oxygen:

> 6.7 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: 2000 mL
- Type: open. Test substance is not volatile
- Fill volume: 1500 mL
- Aeration: Slight aeration, not specified
- Renewal rate of test solution: Semistatic, daily renewal
- No. of organisms per vessel: 10
- No. of vessels per concentration (replicates): 2
- Biomass loading rate: 150 mL/fish
TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: DSWL, prepared from ground water
OTHER TEST CONDITIONS
- Adjustment of pH: no
- Photoperiod: No data
- Light intensity: No data
EFFECT PARAMETERS MEASURED:
Mortality, condition of survivors, sampled every 24 h

Duration:

96 h

Dose descriptor:

NOEC

Effect conc.:

1 mg/L

Key result

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

> 1 - 1.8 mg/L

Duration:

96 h

Dose descriptor:

LC100

Effect conc.:

1.8 mg/L

Details on results:

- Mortality of control: No mortality was observed in the controls after 24, 48, 72 and 96 hours

Sublethal observations / clinical signs:

No confidence interval could be calculated because of the steep concentration-effect curve. 

Parameter            Nominal conc. (mg/l) 

24h LC50                     1.8

48h LC50                     1.3

72h LC50                     1.3

Validity criteria fulfilled:

yes

Conclusions:

The test results indicate that Chlorhexidine dihydrochloride is acutely toxic towards fish. The 96h-LC50 was determined to be 1-1.8 mg/L.

Description of key information

A GLP acute toxicity study with Danio rerio according to the OECD 203 guideline was performed. The test results indicate that Chlorhexidine dihydrochloride is acutely toxic towards fish. The 96h-LC50 was determined to be 1-1.8 mg/L.