1,1,1,3,3,3-hexafluoro-2-methoxypropane

Short-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

23 January 2019 thru 25 January 2019

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Deviations:

no

Remarks:

Extra care was taken to prevent volatilization of substance.

GLP compliance:

yes

Specific details on test material used for the study:

Reference ID: Propane, 1, 1, 1, 3, 3, 3-hexafluoro-2-methoxy- / CAS No. 13171-18-1
Label ID: 1,1,1,3,3,3,-HEXAFLUORO-2-METHOXYPROPANE-CAS NO.: 13171-18-1
LOT #: 17004
Date & Qty. Received: 06 Nov 18; 65.1 g (GW)
Physical Description: Clear liquid
Storage: Room temperature

Analytical monitoring:

yes

Details on sampling:

- Concentrations: 0, 6.25, 12.5, 25, 50, 100 mg/L

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)

Method: The definitive stock solution was prepared by using a gas tight syringe to introduce 370 µL of test substance in 2000 mL of dilution water, stoppered and stirred vigorously for 15 minutes. This stock solution was diluted with dilution water to make five different test substance solutions with five different concentrations for the definitive test. Solutions for the definitive test were prepared from the stock solution and stirred vigorously for 15 minutes after preparation.

Controls: dilution water only.
Chemical name of vehicle (organic solvent, emulsifier or dispersant): none
Concentration of vehicle in test medium (stock solution and final test solution(s) or suspension(s) including control(s)): not applicable
Evidence of undissolved material (e.g. precipitate, surface film, etc.): none

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Daphnia magna
- Strain/clone: not applicable
- Justification for species other than prescribed by test guideline: One of the daphnid species specified in the OCSPP regulations.
- Source: STILLMEADOW, Inc. culture laboratory
- Age of parental stock (mean and range, SD): No greater than 24 hours old at dosing
- Feeding during test:
- Food type:
- Amount:
- Frequency:

ACCLIMATION
- Acclimation period: 48 hours
- Acclimation conditions (same as test or not): yes
- Type and amount of food: none
- Feeding frequency: not applicable
- Health during acclimation (any mortality observed): none

METHOD FOR PREPARATION AND COLLECTION OF EARLY INSTARS OR OTHER LIFE STAGES: Not applicable

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Post exposure observation period:

none

Hardness:

235 mg/L CaCO3

Test temperature:

21 deg C

pH:

7.7

Dissolved oxygen:

91 - 98%

Salinity:

Not applicable

Conductivity:

641 - 686 umhos/cm

Nominal and measured concentrations:

Nominal: 6.25, 12.5, 25, 50, 100 mg/L. To account for volatilization losses during preparation and sampling of solutions, nominal dose concentrations were calculated based on an active of 40% concentration and a density of 1.38 g/mL.
Measured (at start): ND, 49.9, 56.1, 72.8, and 125.7 mg/L; where ND=Non Detected
Measured (at 24 hours old): ND, ND, 44.1, 56.5, and 60.0 mg/L; where ND=Non Detected
Measured (at 48 hours old): ND, ND, 39.2, 43.6, and 44.5 mg/L; where ND=Non Detected

Details on test conditions:

TEST SYSTEM
- Test vessel: 250 mL glass beakers
- Type (delete if not applicable): closed/stoppered
- Headspace: minimized to greatest extent possible.
- Aeration: No
- Type of flow-through (e.g. peristaltic or proportional diluter): Not applicable
- Renewal rate of test solution (frequency/flow rate): Not applicable
- No. of organisms per vessel: 5
- No. of vessels per concentration (replicates): 4
- No. of vessels per control (replicates): 4
- No. of vessels per vehicle control (replicates): not applicable
- Biomass loading rate: not applicable


OTHER TEST CONDITIONS
- Adjustment of pH: 7.7
- Photoperiod: 12 hours

EFFECT PARAMETERS MEASURED (with observation intervals if applicable): Mortality and other abnormalities at 0 hours, 24 hours, and 48 hours.

VEHICLE CONTROL PERFORMED: not applicable

RANGE-FINDING STUDY
- Test concentrations: 0.01, 0.1, 1, 10, and 100 mg/L.
- Results used to determine the conditions for the definitive study: no mortality at any concentration.

Reference substance (positive control):

no

Key result

Duration:

48 h

Dose descriptor:

LC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Remarks:

Measured concentration at time zero was 125.7 mg/L

Basis for effect:

mortality

Details on results:

- Behavioural abnormalities: Yes, animals sunk to the bottom and movements were abnormal but this effect is believed to be the result of a reduction in the surface tension of the test solution.
- Observations on body length and weight: Not determined
- Mortality of control: 10%
- Other adverse effects control: None reported.
- Abnormal responses: Animals sunk to the bottom and movements were abnormal but this effect is believed to be the result of a reduction in the surface tension of the test solution.
- Any observations (e.g. precipitation) that might cause a difference between measured and nominal values: Yes, substance volatilizes rapidly from water.
- Effect concentrations exceeding solubility of substance in test medium: No

Definitive Test Mortality Results:

Concentration (mg/L)*	Replicate	Number of Surviving Organisms**			Mortality (%)
		0 hours	24 hours	48 hours
Control	A	5	5	3	10
	B	5	5	5
	C	5	5	5
	D	5	5	5
6.25	A	5	5	4	5
	B	5	5	5
	C	5	5	5
	D	5	5	5
12.5	A	5	5	5	0
	B	5	5	5
	C	5	5	5
	D	5	5	5
25	A	5	3	3	15
	B	5	5	5
	C	5	5	5
	D	5	5	4
50	A	5	4	5	0
	B	5	3	5
	C	5	3	5
	D	5	4	5
100	A	5	4	5	0
	B	5	4	5
	C	5	3	5
	D	5	3	5

*Nominal

**Some animals reported as dead recovered later. At higher concentrations, organisms sunk to the bottom and began to twitch or were sluggish but otherwise looked normal. Some only moved when prompted.

Validity criteria fulfilled:

yes

Conclusions:

The 48-hour LC50 for Daphnia magna is >100 mg/L.

Executive summary:

In a GLP guideline study conducted according to OECD Method 202, Daphnia magna were exposed to the test substance under static conditions in tightly sealed containers at nominal concentrations of 0, 6.25, 12.5, 25, 50, and 100 mg/L (measured concentrations at time zero were ND, 49.9, 56.1, 72.8, and 125.7 mg/L where ND=Not Detected). No Mortalities were observed at the top doses and mortalities at lower doses were not statistically different from controls. Observed abnormalities included animals sunk to the bottom and movements were abnormal but this effect is believed to be the result of a reduction in the surface tension of the test solution and has been reported with other fluorinated hydrocarbons. As expected, the substance was found to easily volatilze from water despite taking great care to minimize these losses. Based on these results, the 48 -hour LC50 for Daphnia magna is >100 mg/L and can be considered to not pose a danger in the aquatic environment.

Description of key information

In a GLP guideline study conducted according to OECD Method 202, Daphnia magna were exposed to the test substance under static conditions in tightly sealed containers at nominal concentrations of 0, 6.25, 12.5, 25, 50, and 100 mg/L (measured concentrations at time zero were ND, 49.9, 56.1, 72.8, and 125.7 mg/L where ND=Not Detected). No Mortalities were observed at the top doses and mortalities at lower doses were not statistically different from controls. Observed abnormalities included animals sunk to the bottom and movements were abnormal but this effect is believed to be the result of a reduction in the surface tension of the test solution and has been reported with other fluorinated hydrocarbons. As expected, the substance was found to easily volatilze from water despite taking great care to minimize these losses. Based on these results, the 48 -hour LC50 forDaphnia magnais >100 mg/L and can be considered to not pose a danger in the aquatic environment.