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

Short-term toxicity to aquatic invertebrates

Administrative data

Endpoint:

short-term toxicity to aquatic invertebrates

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 202 (Daphnia sp. Acute Immobilisation Test)

Principles of method if other than guideline:

The procedures used in the test were also based on the recommendations of EPA TSCA Guidelines 40 CFR 797.1300 (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 3.47, 6.94, 13.9, 27.7, 55.2 mg/l
At the start of the test a 2 ml sample was taken from each of the two additional bottles containing the freshly prepared test and control media. Samples were removed through a septum in the top of each bottle and were placed into sealed analytical vials. The sampling procedure was repeated at the study termination using 2 of the 4 test bottles at each level before they were opened for water quality measurements.

Test solutions

Vehicle:

no

Details on test solutions:

The test media were made individually by dilution of aqueous stock solutions prepared in the test dilution water in a cold room (nominally 5ºC). Aqueous stock were shaken until all of the test material had disappeared before use. A control group was placed in dilution water alone.

Test organisms

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: water flea
- Strain: not reported
- Source: University of Sheffield
- Age at study initiation (mean and range, SD): 6-24 hours old
- Weight at study initiation (mean and range, SD): not reported
- Length at study initiation (length definition, mean, range and SD): not reported
- Method of breeding: daphnia were fed 5 times/week with suspension of the alga C.vulgaris (from 2 x 10E5 to 8x10E5 cells/ml) and yeast (0.04 mg/l).
- Feeding during test: no

ACCLIMATION
- Acclimation period: no

Study design

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Test conditions

Hardness:

214 to 236 mg/L (as CaCO3)

Test temperature:

20.6 ± 0.2ºC

pH:

7.7-8.0

Dissolved oxygen:

91-98% air saturation value

Salinity:

treated tap water

Nominal and measured concentrations:

nominal concentrations of 3.47, 6.94, 13.9, 27.7, and 55.2 mg/L

Details on test conditions:

The test vessels were all glass vials of approximately 120 mL capacity sealed with a rubber septum and a metal cap. Each test vessel was completely filled with water and 5 daphnia were added. The bottles were then sealed, with care being taken to ensure that there was no airspace. An aliquot of the appropriate stock was injected into each test vessel which were again fitted with a hypodermic needle to allow the excess water to be displaced. Four vessels, each containing 5 animals, were employed for each test and control group. Two additional vessels were also established at each concentration for use at the start of the test. Samples for chemical analysis and water quality measurements were taken from these bottles.

The day length was controlled, giving a photoperiod of 16 hours light and 8 hours darkness.

Alkalinity was 140-150 mg/L as CaCO3.

Measured levels of HCFC-123 in the aqueous stock solutions immediately after preparation ranged between 73 and 108% of their nominal values.

The temperature, pH, and concentration of dissolved oxygen of the dilution water and preparations of test substance at each exposure concentration were measured at the start and end of the test. The total hardness and alkalinity of the dilution water control were measured at the start and end of the test. Exposure levels were monitored by a GC method of analysis at the start of the test and at 48 hours. Observations of the daphnia were made after 24 and 48 hours of exposure.

Results and discussion

Effect concentrations

Effect concentrations 1

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

< 2.24 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Effect concentrations 2

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

17.3 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

95% confidence interval, 13.6-23.1 mg/L (mean measured concentration).

At all concentrations, test media were clear and colorless. Results of duplicate samples at the beginning of the test indicated that achieved HCFC-123 concentrations were lower than intended (between 54 and 76% of their nominal values), but measured levels increased during the test (to between 119 and 141% of the starting concentrations after 48 hours). Measure concentrations are reported in table 1. The lowest HCFC-123 concentration employed (mean measured value 2.24 mg/L) resulted in 5% immobilization and the highest (mean measured value 44.0 mg/L) caused 100% immobilization after 48 hours. The 48-hour EC50 of HCFC-123 for immobilization, calculated using mean measured concentrations, was 17.3 mg/L.

Reported statistics and error estimates:

The 24-hour values were approximations, obtained by nonlinear interpolation between nominal concentrations of 27.7 and 55.4 mg/L.
The 48-hour EC50 value was calculated by the moving average method.

Any other information on results incl. tables

Table 1 measured concentrations (mg/l)

	Nominal concentrations (mg/l)
Sampling	0	3.47	6.94	13.9	27.7	55.2
0 h	n.d.	2.02 – 1.75	5.71 – 4.70	8.85 – 12.4	20.6 – 19.6	38.1 – 38.2
Mean (as % of nominal)	-	54	75	76	73	69
48 h	n.d.	2.60 – 2.59	6.75 – 6.78	11.8 – 13.5	27.0 – 29.5	49.6 – 49.9
Mean (as % of nominal)	-	75	97	91	102	90

Table 2 immobilised daphnia at 24 and 48 hours

	Nominal concentrations (mg/l)
	0	3.47	6.94	13.9	27.7	55.2
24 h	0/20	0/20	0/20	0/20	6/20	20/20
48 h	1/20	1/20	2/20	3/20	10/20	20/20

Applicant's summary and conclusion

Conclusions:

The lowest HCFC-123 concentration employed (mean measured value 2.24 mg/L) resulted in 5% immobilization, and the highest (mean measured value 44.0 mg/L) caused 100% immobilization after 48 hours. The 24- and 48-hour EC50 of HCFC-123 for immobilization, calculated using mean measured concentrations, were 27.7 and 17.3 mg/L, respectively.