α-chloro-o-xylene

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

Study period:

1984-10-22 to 1984-10-26

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

test procedure in accordance with generally accepted scientific standards and described in sufficient detail

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

Principles of method if other than guideline:

Test Method: According to EPA guidelines as outlined in Pellier and Weber (1984)
Test Type: 96-hour static replacement method
Test Endpoint: Mortality
Dose Descriptor: LC50

GLP compliance:

no

Remarks:

Quality Assurance (QA) and Quality Control (QC) followed in this study but in accordance to EPA guidelines

Specific details on test material used for the study:

Name as cited in study: 0-Methylbenzylchloride
Purity: Not specified
Manufacturer and location: Shell Chemical Company, Axis, Alabama
Test material sample preparation or storage: Room Temperature
Test material sample delivery time/date: 1984-10-04
Test material appearance: Colorless liquid

Analytical monitoring:

yes

Details on sampling:

Not specified.

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Nominal or measured test material concentrations: Nominal (verified by analysis)
- Controls: Positive control with reference substance potassium chromate, negative control only with reconstituated water
- Evidence of undissolved material (e.g. precipitate, surface film, etc.): No

Test organisms (species):

Pimephales promelas

Details on test organisms:

TEST ORGANISM
- Common name: Fathead minnow
- Source: NTSU-IAS Stock culture
- Age at study initiation: 20-25 days
- Length at study initiation (length definition, mean, range and SD): 10-15 mm
- Weight at study initiation: Not specified
- Method of breeding: According to EPA procedure
- Maintenance of the brood fish: Moderately hard water, feeding with live Artemia nauplii

MAINTENANCE DURING CULTURE
- Water Supply: Flow-through system with dechlorinated and reconstituted moderately hard tap water
- Filter System: Carbon filter system to control the accumulation of metabolic wastes in the water
- Dissolved Oxygen: maintained near the 100% saturation level throughout the test (air stones)
- Maintenance: Tanks cleaned weekly or more often
- Feeding: Live Artemia nauplii, fed twice daily

ACCLIMATION
- Acclimation period: Not specified
- Acclimation conditions (same as test or not): Same as test
- Type and amount of food during acclimation: Live Artemia nauplii
- Feeding frequency during acclimation: Not specified
- Health during acclimation (any mortality observed): Not specified

FEEDING DURING TEST: No

Test type:

semi-static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

96 h

Post exposure observation period:

no

Hardness:

76 mg/L CaCO3

Test temperature:

- Screening test: 20 °C
- Main test: 21 °C

pH:

SCREENING TEST
Control: 7.9
Test item: 7.9

MAIN TEST
Control: 7.9
Test item (50.0 ppm): 7.8

Dissolved oxygen:

- Screening test: 8.1-8.3 mg/L
- Main test: 7.2-8.0 mg/L

Salinity:

not determined

Conductivity:

SCREENING TEST
Control: 390 µS
Test item: 380 µS

MAIN TEST
Control: 390 µS
Test item (50 ppm): 365 µS

Nominal and measured concentrations:

Only nominal concentrations available.
Concentration Verified: Yes
- Screening test: 1, 10, 20, 50, 100 ppm (nominal)
- Main test: 2.0, 5.0, 10.0, 25.0, 50.0 ppm (nominal)

Details on test conditions:

TEST SYSTEM
- Test vessel: Jars
- Material, size, headspace, fill volume: 1 Gallon (1 Liter test solution volume)
- Renewal rate of test solution (frequency/flow rate): Not specified
- No. of organisms per vessel: 10
- Loading: <= 0.8 g/L
- No. of vessels per concentration (replicates): 2
- No. of vessels per negative control (replicates): 2

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Not specified

OTHER TEST CONDITIONS
- Adjustment of pH: No
- Photoperiod: 8-16 h light/24 h
- Light intensity: 50-100 TC

EFFECT PARAMETERS MEASURED: Mortality

TEST CONCENTRATIONS
- Justification for concentrations: Concentrations based on range finding test
- Range finding study: yes
- Test concentrations in range finding study: 1, 10, 20, 50, 100 ppm
- Test concentrations in main test: 2.0, 5.0, 10.0, 25.0 and 50.0 ppm

Reference substance (positive control):

yes

Remarks:

Potassium chromate

Key result

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

6.8 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Details on results:

- Other adverse effects control: No
- Abnormal responses: No
- Any observations (e.g. precipitation) that might cause a difference between measured and nominal values: No
- Effect concentrations exceeding solubility of substance in test medium: No

Results with reference substance (positive control):

96-h LC50 = 40.9 mg/L with
95% confidence limit: 34.5 to 46.9 mg/L

Reported statistics and error estimates:

To estimate the LC50 values a computer software devloped by C.E. Stephan (1977) was used.

Sublethal observations / clinical signs:

Table 1: Results of the screening test.

		Test Container No	No of Live Organisms		Dissolved Oxygen mg\L		pH		Temp °C		Alkalinity mg/L CaCo3		Hardness mg/L CaCo3		Conductivity µS
			0	24	0	24	0	24	0	24	0	24	0	24	0	24
Control		1	10	10	8.3	8.2	7.9	7.9	20	20	60	60	76	76	390	390
		2	10	10	8.3	8.2	7.9	7.9	20	20	60	60	76	76	390	390
		3	10	10	8.3	8.2	7.9	7.9	20	20	60	60	76	76	390	390
		4	10	10			7.9	7.9	20	20	60	60	76	76	390	390
		5	10	10			7.9	7.9	20	20	60	60	76	76	390	390
Concentration in ppm	1	1	10	10	8.2	8.2	7.9	7.9	20	20	60	60	76	76	380	380
	10	2	10	10	8.2	8.1	7.9	7.9	20	20	60	60	76	76	380	380
	20	3	10	10	8.2	8.1	7.9	7.9	20	20	60	60	76	76	380	380
	50	4	10	0			7.9	7.9	20	20	60	60	76	76	380	380
	100	5	10	0			7.9	7.9	20	20	60	60	76	76	380	380

Table 2: Results of the main test (static renewal).

Concentration	Test Container No	No of Live Organisms					Dissolved Oxygen mg\L					pH		Temp °C		Alkalinity mg/L CaCo3		Hardness mg/L CaCo3		Salinity %o	Conductivity µS
		0	24	48	72	96	0	24	48	72	96	0	%	0	%	0	%	0	%		0	%
Control	1	10	10	10	10	10	8.0	7.4	7.4	7.4	7.4	7.9	7.9	21	21	60	60	76	76		390	390
	2	10	10	10	10	10	8.0	7.4	7.4	7.4	7.4	7.9	7.9	21	21	60	60	76	76		390	390
2.0 ppm	1	10	10	10	10	10
	2	10	10	10	10	10
5.0 ppm	1	10	10	10	10	10	8.0	7.2	7.4	7.4	7.4
	2	10	10	10	9	9	8.0	7.2	7.4	7.4	7.4
10.0 ppm	1	10	0	0	0	0
	2	10	0	0	0	0
25.0 ppm	1	10	0	0	0	0
	2	10	0	0	0	0
30.0 ppm	1	10	0	0	0	0	8.0	7.2				7.8	7.8	21	21	60	60	76	76		365	365
	2	10	0	0	0	0	8.0	7.2				7.8	7.8	21	21	60	60	76	76		365	365

Validity criteria fulfilled:

yes

Description of key information

The 96-h LC50 for fish was determined to be 6.75 mg/L with 95% confidence limit of 5 to10 mg/L.

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Effect concentration:

6.75 mg/L

Additional information

The acute toxicity of the test item to fathead minnows (Pimephales promelas) was determined in a 96-hour test equivalent to OECD Guideline No. 203 (Shell Oil Co., 1984). In this semi-static test, fathead minnows were exposed to an aqueous test medium (reconstituated, dechlorinated and moderatley hard tap water) containing the test item at five nominal concentrations of 2 to 50 mg/L (verified by analysis). This range was based on results of a preliminary study with concentrations from 1 to 100 mg/L (nominal). Two vessels per concentration and the parallel negative control (only with reconstituated water) were each loaded with ten test animals. In addition, a positive control with hexavalent chromium as reference substance was investigated. In result, the 96-h LC50 for Pimephales promelas was determined to be 6.75 mg/L (nominal) with a 95% confidence limit of 5 to10 mg/L. The 96-h LC50 of hexavalent chromium was 40.9 mg/L (nominal) with a 95% confidence limit of 34.5 to 46.9 mg/L (similar to results published in the Ambient Water Quality Criteria for Chromium of EPA, 1983). In the negative control no mortality was observed throughout the study period. During the test, temperature was 21 °C; the measured dissolved oxygen concentration was 8.0 mg/l at the start and 7.4 mg/L at the end of the test. Thus, the test is regarded as valid.