Tetrahydro-3-pentyl-2H-pyran-4-yl acetate

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:

13 September 2000 - 26 October 2000

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

Reliability 2 is assigned because the study was conducted according to OECD TG 202 in compliance with GLP, however without specific analysis to confirm test substance concentrations. Nonetheless, there were no deviations that influence the quality of the results.

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Version / remarks:

(Part I, 1984)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Details on sampling:

Test concentrations were verified by Total Organic Carbon (TOC) analysis.
Duplicate samples were taken from the control and each exposure level.

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Preparation method:
Suspensions of the test substance were prepared in test medium by adding weighed amounts of test substance to the medium whilst shaking. Each test concentration was prepared separately. After a shaking period of 24 hrs the suspensions were filtered over water pre-wetted filter paper and the filtrates were directly used for the test without further dilution.

- Application method:
In view of (partial) adsorptive properties of the test substance, test vessels were pre-incubated with the respective test solution to assure saturation of the surfaces of the glass walls with test substance. After approximately 1 hour of pre-incubation time the test solutions were replaced with a fresh portion of the same solution to be used in the test.

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Daphnia magna
- Strain: not reported
- Source: in-house laboratory culture (originally derived from Dr. Knie, LWA Duesseldorf)
- Age at study initiation: daphnids not older than 24 hours.

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Post exposure observation period:

none

Hardness:

not reported

Test temperature:

20.0 +/- 0.1°C

pH:

7.1 - 7.6

Dissolved oxygen:

7.9 - 8.7 mg O2/L

Nominal and measured concentrations:

Nominal loading rates: 0, 20, 40, 80, 160 and 320 mg/L.
Mean measured test concentrations at test start (based on TOC results and corrected for purity): 0, 22, 41, 79, 145 and 294 mg/L.
Mean measured test concentrations at test end (based on TOC results and corrected for purity): 0, 22, 42, 81, 141 and 294 mg/L.

Since nominal loading rates were confirmed by chemical analysis to be within 80-120% of nominal, they are further regarded as nominal concentrations.

Nominal concentrations were used for the effect assessment because concentrations were shown to remain within 80-120% of nominal throughout the test.

Details on test conditions:

TEST SYSTEM
The tests were performed in closed bottles (100 mL-carboys) filled up to the neck with test solution because of the volatile nature of the test substance.

* Screening test:
- Three test concentrations (1.0, 10 and 100 mg/L) plus one control each in duplicate with 5 animals/test vessel (i.e. 10 animals/concentration).

* Main test
- Five test concentrations (20, 40, 80, 160 and 320 mg/L) plus one control each in 4-fold with 5 animals/test vessel (i.e. 20 animals/concentration).
- Loading rate: ca. 20 ml test solution per organism
- Test vessels were maintained at 20 °C under a photoperiod of 16 hours light : 8 hours dark and without supplementary aeration or feeding during the 48 hour exposure period.
- The temperature in each vessel, the pH and dissolved oxygen levels were recorded at the start and at the end of the study.

EFFECT PARAMETERS MEASURED:
Daphnia were considered to be immobile if they were unable to swim within 15 seconds after gentle agitation of the test vessel.

Reference substance (positive control):

yes

Remarks:

potassium dichromate (once a month)

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

78 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: Nominal concentrations were confirmed by TOC analysis. 95% Confidence level: 21%

Details on results:

Recovery: Measured concentrations ranged from 91 - 110 % of nominal at 0 hours and 88-112 % of nominal at 48 hours.
Relative to initial [%] ranged from 96.8 - 102.2%.

Individual pH, temperature and dissolved oxygen values remained within acceptable limits throughout the duration of the study.

Vailidity criteria fulfilled, i.e. <10% immobility or trapping at the water surface in the control and dissolved oxygen concentration at the end of the test was >= 60% of the air saturation at the temperature used.

Results with reference substance (positive control):

EC50: 0.9 mg/L

Reported statistics and error estimates:

48 h-EC50 standard deviation: 6%

Main test

 

Cumulative immobilisation data for Daphnia magna exposed for 48 hours to the test substance

 

Nominal concentration     [mg/L]	Mean measured concentration at t=48 h [mg/L]	Cumulative immobilised Daphnia magna (initial population: 20 per replicate)
		24 hours		48 hours
		total	%	total	%
control	0	0	0	0	0
20	22	0	0	0	0
40	42	0	0	1	5
80	81	1	5	13	65
160	142	4	20	17	85
320	294	20	100	20	100

Validity criteria fulfilled:

yes

Remarks:

<10% immobility or trapping at the water surface in the control; at t=48 h dissolved O2 concentration >= 60% of the air saturation at the temperature used

Conclusions:

The 48 h EC50 (immobilisation) value with Daphnia magna is 78 mg/L.

Executive summary:

A study was performed to assess the acute toxicity of the substance to Daphnia magna. The study was conducted under static conditions in accordance with OECD Guideline for Testing of Chemicals No. 202. Groups of twenty, 1st instar Daphnia (less than 24 hours old) were exposed in closed bottles for 48 hours to 5 concentrations of filtered substance extracts in test water (nominal concentrations up to 320 mg/L). The incidence of immobilisation was recorded for each test and control group at 24 hours and at 48 hours. The 48 h EC50 value was 78 mg/L. All results are expressed in terms of nominal concentrations. Mean measured TOC concentrations ranged from 91 - 110 % of nominal at 0 hours and 88 - 112 % of nominal at 48 hours.

Description of key information

See below

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

78 mg/L

Additional information

A study was performed to assess the acute toxicity of the substance to Daphnia magna. The study was conducted under static conditions in accordance with OECD Guideline for Testing of Chemicals No. 202.Closed test vessels were used to prevent evaporation of test substance. Due to expected (partial) adsorptive properties of the test substance, test vessels were pre-incubated with the respective test solution to assure saturation of the surfaces of the glass walls with test substance.Groups of twenty, 1st instar Daphnia (less than 24 hours old) were exposed in closed bottles for 48 hours to 5 concentrations of filtered substance extracts in test water (nominal concentrations up to 320 mg/L). The incidence of immobilisation was recorded for each test and control group at 24 hours and at 48 hours. The 48 h EC50 value was 78 mg/L. All results are expressed in terms of nominal concentrations. Mean measured TOC concentrations ranged from 91 - 110 % of nominal at 0 hours and 88 - 112 % of nominal at 48 hours.