2,2,6,6-tetramethyl-4-substituted-piperidinyl-1-oxy

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

Study period:

February 14th - 16th 2006

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Guideline study conducted in accordance with GLP.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2006

Report date:

2006

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

other: EEC C2: Acute toxicity to Daphnia OECD 202: Acute immobilisation test

Test guideline 2

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Test material form:

other: Liquid

Sampling and analysis

Analytical monitoring:

yes

Details on sampling:

Samples of the test solutions in which the organisms were exposed, were taken for analytical verification at the start of the definitive study, before and after renewal of solutions at 24 hours and at the end of the 48 hour exposure period. Samples were frozen at -22ºC until test substance specific analysis of each test concentration was carried out.

Test organisms

Test organisms (species):

Daphnia magna

Details on test organisms:

Culture derived from IRCHA type A (clone5)
Source: Shell Research Laboratories
Age of Daphnia at start of test: Less than 24 hours

Study design

Test type:

semi-static

Water media type:

not specified

Total exposure duration:

48 h

Test conditions

Hardness:

156 mg CaCO3/L

Test temperature:

20±1 ºC

pH:

7.8±0.2

Dissolved oxygen:

60% minimum

Nominal and measured concentrations:

The definitive test concentrations were prepared as; 0 (control), 5, 10, 20, 40, 80 and 160 mg/l

Details on test conditions:

Preparation of test solutions
A 160 mg/l stock solution of Inhibitor AHM P500 was prepared in dilution water. The test concentrations were prepared by addition of the appropriate volume of the stock solution to the dilution water to give the required concentrations for the test.
The definitive test concentrations were prepared as; 0 (control), 5, 10, 20, 40, 80 and 160 mg/l

Definitive toxicity procedure
Five Daphnia were transferred into four replicate 50 ml dishes containing 25ml of dilution water. The test vessels were placed into an incubator at 21 ±1 ºC with a light cycle of sixteen hours light and eight hours dark. To limit aerial contamination of the test vessels and reduce evaporative loss, a transparent perspex sheet was placed over the tops of the dishes.

Reference substance (positive control):

yes

Remarks:

Water

Results and discussion

Effect concentrations

Effect concentrations 1

Duration:

24 h

Dose descriptor:

EC50

Effect conc.:

75 mg/L

Effect concentrations 2

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

19 mg/L

Effect concentrations 3

Duration:

48 h

Dose descriptor:

EC100

Effect conc.:

80 mg/L

Effect concentrations 4

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

10 mg/L

Details on results:

- Behavioural abnormalities: At 24 hrs some daphnids showed slower swimming at a concentration of 40 mg/L, at 48 hrs all remaining daphnids showed slower swimming at 20 and 40 mg/L.
- Mortality of control: No immobilised daphnids were observed in the control.
- Any observations (e.g. precipitation) that might cause a difference between measured and nominal values: None

Results with reference substance (positive control):

- Results with reference substance valid? Yes
- EC50/LC50 of reference subtstance potassium dichromate: 0.36 mg/L
- Other:

Any other information on results incl. tables

The number of Daphnids immobilised and the cumulative % immobilisation are presented in Table 1.

Nominal Concentration mg/L	Number immobilised		% immobilisation
	24 hours	48 hours	24 hours	48 hours
0	0	0	0	0
5	0	0	0	0
10	0	0	0	0
20	2	13	10	65
40	4	19	20	95
80	11	20	55	100
160	16	20	80	100

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

The 48-hour EC50 value of inhibitor AHM P500 to Daphnia magna was estimated to be 19 mg/l. The highest no observed effect concentration (NOEC) after 48 hours was 10 mg/l. The lowest test concentration that immobilised all twenty Daphnia within 48 hours was 80 mg/l
All Daphnia that were noted immobile at 24 and 48 hours were subjected to careful observation and were judged as dead. No Daphnia were observed alive but immobile. No other adverse effects on the organisms were noted.

Executive summary:

A study was performed in accordance with OECD 202 and to GLP, to determine the effects of Inhibitor AHM P500 to Daphnia magna.

The study was performed under semi-static conditions at test concentrations of 0, 5, 10, 20, 40, 80 and 160 mg/L defined in a preliminary test.

Potassium dichromate was employed as the reference substance.

All Daphnia that were noted immobile at 24 and 48 hours were subjected to careful observation and were judged as dead. No Daphnia were observed alive but immobile.

Validity criteria for the reference substance and blank (0 mg/L) were considered met.

The 48-hour EC50 value of Inhibitor AHM P500 to Daphnia magna was estimated to be 19 mg/l. The highest no observed effect concentration (NOEC) after 48 hours was 10 mg/l.