cis-4-[3-(p-tert-butylphenyl)-2-methylpropyl]-2,6-dimethylmorpholine

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:

16.- 25.11.99

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

EPA OPPTS 850.1010 (Aquatic Invertebrate Acute Toxicity Test, Freshwater Daphnids)

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

GLP compliance:

yes

Specific details on test material used for the study:

Fenpropimorph (Reg. No. 108 406); batch no. N 103; purity: 96.6%

Analytical monitoring:

yes

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Waterflea
- Age at study initiation: 2 - 24 h (starting with the 3rd breed of parent animals)
- Source: Institut National de Recherche Chimique Appliquée, France, in 1978; since then Laboratory of Ecology of BASF AG in Ludwigshafen
- Age of parental stock: 2 - 4 weeks
- Feeding during test: None

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Hardness:

2,20 - 3,20 mmol/I

Test temperature:

20,4 - 20,9 °C

pH:

8,1 - 8,3

Dissolved oxygen:

8,2 - 8,7 mg/l

Conductivity:

550 - 650 µS/cm

Nominal and measured concentrations:

nominal: control; 0,3, 1, 3, 10, 30 and 100 mg/I;
values of the concentration control analysis were above 80% of nominal.

Details on test conditions:

TEST SYSTEM
- Test vessel: Test tubes (glass) with flat bottom (nominal volume 20 ml)
- Material, fill volume: glass; 10 ml test volume
- Aeration: until saturation with oxygen is reached; 8,2 - 8,7 mg/l
- No. of organisms per vessel: 5
- No. of vessels per concentration (replicates): 4
- No. of vessels per control (replicates): 4
- Biomass loading rate: 0,5

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: preparation based on an ultrapure, demineralized water with a conductivity < 0.05 pS/cm; for the composition of this M4 medium see ISO 10706
- Alkalinity: 0,80 - 1,00 mmoI/I (up to pH 4.3)
- Ca/mg ratio: about 4 : 1
- Conductivity: 550 - 650 µS/cm

OTHER TEST CONDITIONS
- Photoperiod: Artificial light. type warm white (e.g. OSRAM L58 W31) day/night rhythm = 16 : 8 h
- Light intensity: About 2 - 7 µE/(m2*s) at a wave length of 400 - 700 nm

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :
Swimming ability of the test animals: Animals which were unable to swim within 15 seconds, even after gentle agitation of the test vessel were
considered to be immobile.

Duration:

48 h

Dose descriptor:

EC0

Effect conc.:

1 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

EC100

Effect conc.:

10 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

2.24 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

Analytical measurements: Analytical verification of the test substance concentrations was conducted in each concentration at the beginning without daphnids and at the end of the test with daphnids. In general, the analytical results varied between 78.2% and 91.4% of the nominal concentrations at test initiation. At the end of the test 78.5% - 89.3% of the nominal concentration were detected for concentrations of 0.3 mg/L to 3.0 mg/L. Low recovery values of 25.1% - 66.7% were obtained for concentrations of 10 mg/L. The decline is probably due to precipitation of fenpropimorph in the course of the study since the maximum water solubility is 4 mg/L.
As the analytical recovery in concentrations in the range of the EC50 was on average above 80% of nominal, the biological results of this study are based on nominal concentrations.

Biological results: Treatment-related immobility of the daphnids was observed at test concentrations of 3.0 mg/L (70%), 10 mg/L (100%), 30 mg/L (100%) and 100 mg/L (100%).
EC50 (48 h) = 2.24 mg/L (95% limits: 1.68 - 2.98 mg/L)
EC0 (48 h) = 1.0 mg/L

Table 8.2/25     Effect of fenpropimorph on Daphnia magna immobility
Concentration [mg/L] nominal	Control	0.3	1	3	10	30	100
Immobile (24 hours) [%]	0	0	0	0	100	100	100
Immobile (48 hours) [%]	5	0	10	70	100	100	100

 

Conclusions:

In a 48 hours static acute toxicity study with Daphnia magna the EC50 of fenpropimorph was determined to be 2.24 mg/L, the EC0 was 1.0 mg/L (nominal).

Description of key information

In a 48 hours static study considering the acute toxicity of fenpropimorph to Daphnia magna, the EC₅₀ was determined to be 2.24 mg/L (nominal).

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

2.24 mg/L

Additional information

Two studies on the acute toxicity of fenpropimorph and its metabolite to aquatic invertebrates are available. All studies were conducted according to GLP, OECD 202 and other different international guidelines. The test species was the water flea Daphnia magna STRAUS. The study conducted by Jatzek (1999) yielded the lowest relevant endpoint for the standard species Daphnia magna- it was chosen as key and described further as robust study summary.

In addition, the effect of the main metabolite fenpropimorph-acid (Reg.No. 231346) on Daphnia magna STRAUS in a static acute toxicity test was tested (Dohmen G.P. 1997(a); Reg: 1997/10143). The results are summerized below.
No treatment-related immobility of the daphnids was observed at any of the test concentrations.
In a 48 hours static acute toxicity study with Daphnia magna the EC₅₀ of fenpropimorph-acid was determined to be >100 mg/L, the EC₀/NOEC was 100 mg/L (nominal).