Isophthaloyl dichloride

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:

comparable to guideline study with acceptable restrictions

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

Deviations:

yes

Remarks:

Solubility not determined, actual concentrations not measured, just nominal reported. Appendix and tables missing information such as pH, hardness, etc. Fish not fed 55 hours before test instead of 24 hours. No deviations exist that affected the scientif

GLP compliance:

yes

Analytical monitoring:

no

Vehicle:

no

Details on test solutions:

- Appropriate quantities of the test substance were weighed, added to appropriate volumes of well water and stirred for 2 hours to create individual test solutions. Stability and solubility in dilution water and under storage conditions were not determined.
- Undissolved test substance was observed in all test solutions.

Test organisms (species):

Pimephales promelas

Details on test organisms:

TEST ORGANISM
- Common name: Fathead minnow
- Length at study initiation: 1.3-2.2 cm standard length and 0.004 to 0.099 g for controls, data not provided for treated fish.
- Feeding during test
- Amount: No food 55 hours prior to and during test


ACCLIMATION
- Acclimation period: Reared from egg to size used for test
- Acclimation conditions (same as test or not): Yes for temperature
- Type and amount of food: Artemia sp. (newly hatched)
- Feeding frequency: Twice daily on weekdays and daily on weekends
- Health during acclimation (any mortality observed): No sickness, injury, or abnormality observed

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

96 h

Hardness:

Hardness and alkalinity within expected ranges

Test temperature:

21.5-21.7 degrees C

pH:

Declined over the duration of the test according to the magnitude of the test concentration down to 3.5

Dissolved oxygen:

Within expected ranges

Nominal and measured concentrations:

Rangefinding concentrations: 0.1, 1.0, 10, 100, and 1000 mg/L.
Nominal test concentrations: 78, 130, 216, 360, 600, and 1000 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel:
- Type: open
- Material, size, headspace, fill volume: Glass aquaria of 20 litres, (39(L) x 20(W) x 24 (H)) containing 15L of test solution (approximately 19-cm liquid depth)
- No. of organisms per vessel: 10
- No. of vessels per concentration (replicates): 2
- No. of vessels per control (replicates): Not specified
- Biomass loading rate: 0.035 g/L for control fish
- Photoperiod of 16 hours light (108-366 Lux): 8 hours darkness employed with 25 minutes of transitional light (approximately 2.2 Lux) preceding and following the 16 hour light interval.


TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: well water
- Intervals of water quality measurement: daily for DO, pH, and temperature


OTHER TEST CONDITIONS
- Adjustment of pH: no
- Photoperiod:16 hours light vs. 8 hours darkness with 25 minutes of transitional light
- Light intensity: 108-377 Lux. Transitional light was 2.2 Lux.


EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : Cumulative mortality and behavioural data


TEST CONCENTRATIONS
- Range finding study
- Test concentrations: 0.1, 1.0, 10, 100, and 1000 mg/L

Reference substance (positive control):

no

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

133.7 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Remarks on result:

other: 95% fiducial limit = 116.7-154.9 mg/L

Details on results:

Range-finding test with 5 fish per concentration was conducted with a water control. Mortalities were 0,0,0,0,0 and 100% respectively.
For main test, mortality increased as test solution increased and pH decreased with total kill observed at the 4 highest test concentrations (216, 360, 600, and 100 mg/L), between pH 3.5 and 5.1.

Reported statistics and error estimates:

95% fiducial interval of 96-hr LC50 = 116.7 to 154.9 mg/L

Sublethal observations / clinical signs:

Authors state that low pH effects probably accounted for mortalities at 4 highest test concentrations to a greater degree than direct toxicity of the test material. However, since the pH was within the expected range at the 96 -hour LC50 nominal concentration (unadjusted for undissolved test substance), the observed mortality was probably attributable to inherent compound toxicity.

Validity criteria fulfilled:

yes

Conclusions:

This study established a 96-hour LC50 in fathead minnows of 133.7 mg/L with a 95% fiducial interval of 116.7 to 154.9 mg/L (nominal concentrations).

Executive summary:

Isophthaloyl dichloride exhibited slight toxicity in a 96 -hour, unaerated, static, acute test using fathead minnows, Pimephales promelas. Nominal test substance concentrations were 78, 130, 216, 360, 600, and 1000 mg/L. The 96-hour LC₅₀ was 133.7 mg/L with a 95% fiducial interval of 116.7 to 154.9 mg/L.

Description of key information

The study was conducted similar to OECD 203 under GLP with Fathead minnows,Pimephales promelas. The 96-hour, unaerated, static study used nominal test concentrations of 78, 130, 216, 360, 600 and 1000 mg/L. The test substance exhibited slight toxicity with a LC₅₀of 133.7 mg/L.

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Effect concentration:

133.7 mg/L