2,2-dichloro-1,1,1-trifluoroethane

Short-term toxicity to fish

Administrative data

Endpoint:

short-term toxicity to fish

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: High reliability because a scientifically defensible or guidelined method was used. Critical study for SIDS endpoint. Only study summary reviewed from secondary source.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1992

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

Principles of method if other than guideline:

The procedures used in the test were also based on EPA TSCA Guidelines 40 CFR 797.1440 (1989).

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

2,2-dichloro-1,1,1-trifluoroethane

EC Number:

206-190-3

EC Name:

2,2-dichloro-1,1,1-trifluoroethane

Cas Number:

306-83-2

Molecular formula:

C2HCl2F3

IUPAC Name:

2,2-dichloro-1,1,1-trifluoroethane

Constituent 2

Reference substance name:

Ethane, 2,2-dichloro-1,1,1-trifluoro-

IUPAC Name:

Ethane, 2,2-dichloro-1,1,1-trifluoro-

Details on test material:

- Name of test material (as cited in study report): HCFC-123
- Analytical purity: not reported.
- Name of test material (as cited in study report): HCFC 123
- Molecular formula (if other than submission substance): same as submission
- Molecular weight (if other than submission substance): same as submission
- Smiles notation (if other than submission substance): same as submission
- InChl (if other than submission substance): same as submission
- Structural formula attached as image file (if other than submission substance): same as submission
- Substance type: halogenated ethane
- Physical state: liquid
- Analytical purity: not reported
- Impurities (identity and concentrations): not reported
- Purity test date: not reported
- Lot/batch No.: BB305 D55A
- Expiration date of the lot/batch: not reported
- Stability under test conditions: stable
- Storage condition of test material: at room temperature in the dark

Sampling and analysis

Analytical monitoring:

yes

Details on sampling:

- Concentrations: nominal concentrations of 13.3, 23.5, 42.5, 74.3 and 133 mg/L
- Sampling method: gas chromatography
- Sample storage conditions before analysis: Duplicate samples were removed from each vessel approximately 3 and 24 hours after the addition of the test material on 2 occasions.

Test solutions

Vehicle:

no

Details on test solutions:

Test media were individually prepared in glass aspirators by the direct addition of test material to dilution water and were renewed at 24-hour intervals. HCFC-123 was not easy to disperse so the contents of each aspirator were stirred for 3 hours after preparation to aid dissolution.

Test organisms

Test organisms (species):

Oncorhynchus mykiss (previous name: Salmo gairdneri)

Details on test organisms:

Groups of 10 fish (Fish, estuary, fresh water) were exposed to HCFC-123 in sealed vessels.

Study design

Test type:

semi-static

Water media type:

freshwater

Total exposure duration:

96 h

Test conditions

Hardness:

204 to 230 mg/L (as CaCO3)

Test temperature:

14.0 +/- 7 degrees C

pH:

7.1-7.7

Dissolved oxygen:

62-98% air saturation value (ASV)

Salinity:

Treated tap water

Nominal and measured concentrations:

nominal concentrations of 13.3, 23.5, 42.5, 74.3, and 133 mg/L.

Details on test conditions:

A control group of fish was placed in dilution water alone. After 24, 48, and 72 hours, the surviving fish in each vessel were transferred to another vessel containing fresh dilution water. The test material was then added and the medium stirred for 3 hours. The test and control media were not aerated during the test. The pH was neither adjusted before the start of the test nor controlled during the test. Temperature, pH, and concentration of dissolved oxygen of the contents of each vessel were measured at the start of the test and then each day following observations of fish behavior. The total hardness of the water control and selected test dilutions were also determined.

The fish were last fed 24 hours before the start of the test. The mean wet-weight of the fish was 2.0 g and the mean fork length was 5.4 cm. The day length in the test area was controlled giving a photoperiod of 16 hours light and 8 hours darkness.

Observations of the fish were made at least at 24-hour intervals during the test.

Results and discussion

Effect concentrations

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

55.5 mg/L

Nominal / measured:

meas. (arithm. mean)

Basis for effect:

mortality (fish)

Details on results:

The highest nominal concentration at which no mortalities occurred and the lowest at which there was 100% mortality were 42.5 and 133 mg/L, respectively (mean measured concentrations, 33.3 and 90.6 mg/L). A single death at 13.3 mg/L was not considered treatment-related. The majority of deaths occurred within 24 hours at 133 mg/L (nominal) and within 48 hours at 74.3 mg/L (nominal). Treatment-related effects were seen at all exposure levels. At 74.3 and 133 mg/L (nominal), all fish were affected within 4 hours and, during the course of the test, exhibited darkened pigmentation, lethargic behavior, and loss of coordination. At 13.3, 23.5, and 42.5 mg/L (nominal), respectively, 2, 3, and 4 fish were affected at the end of the test, exhibiting either darkened pigmentation or lethargic behavior.

Reported statistics and error estimates:

The 48-, 72-, and 96-hour LC50 values were approximate because the data did not permit statistically valid calculations. Since mortalities were not progressive during the test, an asymptotic LC50 was thought to have been attained.

Any other information on results incl. tables

Sublethal observations / clinical signs:

Chemical analysis

At all concentrations, the test media were clear and colorless. However, at 133 mg/L (nominal), a globule of test material was still visible 3 hours after preparation, but had disappeared after 24 hours. At all levels except the highest (133 mg/L, nominal), intended concentrations were achieved and maintained (overall range 78-115% of nominal). At the highest level, the mean measured concentration was 68% of nominal. In the first 24 hours of the test, measured levels of HCFC-123 increased suggesting the slow dissolution rate of the material. Analytical results obtained at 75 and 96 hours were less consistent, but overall showed intended levels had been achieved and maintained. Overall, the "closed" system employed was effective at maintaining aqueous levels of the test material. The variation observed was not thought to have affected the integrity of the study since a clear concentration-related response was observed.

Mean measured concentrations are reported in table 1

Table 1: measured concentrations (2 replicates/concentration/timepoint) and mean concentrations (% deviation from nominal concentration reported between brackets)

	Nominal concentrations (mg/l)
Sampling	13.3	23.5	42.5	74.3	133
3 h	14.7 – 15.4	20.2 – 20.7	30.2 – 32.4	48.8 – 51.4	63.2 – 32.3
24 h	16.7 – 16.8	24.3 – 24.3	32.2 – 33.6	76.3 – 77.5	120 – 117
75 h	-*	25.4 – 27.9	-*	72.5 – 72.9	-**
96 h	14.5 – 13.5	19.5 – 18.0	35.5 – 36.0	58.9 – 59.0	-**
mean	15.3 (115%)	22.5 (96%)	33.3 (78%)	64.6 (87%)	90.6 (68%)

*analytical results erroneously too high, not considered to calculated mean measured concentrations

** all fishes at this level were died, no analysis performed

Mortality and effects

Mortality data are reported in Table 2:

Table 2

	Mean Measured concentrations (mg/l)
	15.3	22.5	33.3	64.6	90.6
0.25 h	0/10	0/10	0/10	0/10	0/10
2 h	0/10	0/10	0/10	0/10	0/10
4 h	0/10	0/10	0/10	0/10	0/10
23 h	0/10	0/10	0/10	4/10	9/10
47 h	0/10	1/10	0/10	6/10	10/10
70 h	0/10	1/10	0/10	7/10	10/10
95 h	0/10	1/10	0/10	7/10	10/10

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

The no-observed effect concentration was <13.3 mg/L (mean measured concentration, 15.3 mg/L). Mean lethal concentrations (nominal) at 24, 48, 72, and 96 hours were 83.5, 69.2, 65.4, and 65.4 mg/L, respectively. Mean lethal concentrations (measured) at 24, 48, 72, and 96 hours were 64.1, 59.4, 55.5, and 55.5 mg/L, respectively.