Amylase, gluco-

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:

30 November 2005 - 02 November 2006

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

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Details on sampling:

- Concentrations: 227.9 mg enzyme concentrate dry matter/L
- Sampling method: Triplicate samples (5mL) were taken from the control and test concentration at 0 and 24 hours (fresh media) and at 24 and 48 hours (expired media) for analysis.
- Sample storage conditions before analysis: frozen at -20°C in the dark

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: A sample of the test material weighing 1584 mg was dispersed directly in 1 litre of diluent water to give the nominal test concentration of 227.9 mg enzyme concentrate dry matter/L.
- Controls: medium

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Daphnia magna
- Strain: Straus
- Source: Daphnia magna used in this study were cultured in-house and were obtained from a strain originating from the Institute National de Recherche Chimique Appliqué (IRChA), France
- Age at study initiation (mean and range, SD): less than 24 hours old

Test type:

semi-static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

48 h

Test temperature:

21-22°C

pH:

7.5-7.7

Dissolved oxygen:

7.6-8.2

Nominal and measured concentrations:

A preliminary range finding test was conducted with nominal test concentrations of 1.04, 10.4, 103.6 and 227.9 mg enzyme concentrate dry matter/L.
Definitive study:
Nominal concentrations: 227.9 mg enzyme concentrate dry matter/L.
Measured concentrations: 264.2 mg enzyme concentrate dry matter/L.

Details on test conditions:

TEST SYSTEM
- Test vessel: 250 mL glass jars
- Type (delete if not applicable): loosely covered
- Material, size, headspace, fill volume: glass, 250 ml, fill volume: 100 mL
- Aeration: no (loosely covered jars)
- Renewal rate of test solution (frequency/flow rate): medium renewal after 24 hours
- No. of organisms per vessel: 5
- No. of vessels per concentration (replicates):4
- No. of vessels per control (replicates): 4

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Elendt M4 medium

OTHER TEST CONDITIONS
- Adjustment of pH: no
- Photoperiod: 16 hour light: 8 hour dark

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :
Observations of the condition of the test and control Daphnia were made following 24 and 48 hours exposure. Daphnia were considered to be immobile if they were unable to swim within approximately 15 seconds following gentle agitation of the test vessel.

TEST CONCENTRATIONS
Range finding study
- Test concentrations: 1.04, 10.4, 103.6 and 227.9 mg enzyme concentrate dry matter/L.
- Results used to determine the conditions for the definitive study: yes

Reference substance (positive control):

no

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 227.9 mg/L

Nominal / measured:

nominal

Conc. based on:

other: enzyme concentrate dry matter

Basis for effect:

mobility

Key result

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

>= 227.9 mg/L

Nominal / measured:

nominal

Conc. based on:

other: enzyme concentrate dry matter

Basis for effect:

mobility

Details on results:

- Mortality of control: 0

Validity criteria fulfilled:

yes

Conclusions:

No immobilisation was observed following the exposure of Daphnia magna to the test substance at a concentration of 227.9 mg enzyme concentrate dry matter/L. Due to the low toxicity of the test material, the 48-hour EC50 (immobilisation) value of the substance was unable to be calculated. Therefore, the 48-hour EC50 value of the test substance to Daphnia magna was >227.9 mg enzyme concentrate dry matter/L (equivalent to 103.7 mg active enzyme protein/L).
The no-observed effect concentration (NOEC) was ≥ 227.9 mg enzyme concentrate dry matter/L (equivalent to ≥ 103.7 mg active enzyme protein/L).

Executive summary:

The acute toxicity of the test substance to Daphnia magna was assessed under semi-static exposure conditions. The study was conducted according to OECD and EC guidelines, and in compliance with GLP.

A group of twenty, first instar Daphnia magna, less than 24 hours old, were exposed to the test substance dispersed in Elendt M4 medium for 48 hours at a nominal concentration of 227.9 mg enzyme concentrate dry matter/L.

Verification of test concentrations was performed based on enzyme activity. The amount of measured enzyme (AGU/g) was then converted to mg enzyme concentrate dry matter/L in order to calculate the achieved measured concentrations. Average measured concentrations ranged from 119% of nominal at 0 hours (fresh), 115% at 24 hours (expired), 116% at 24 hours (fresh) and 114% at 48 hours (expired). These results confirmed that the nominal exposure concentration was achieved and maintained satisfactorily for the 24-hour duration between each medium renewal. Mean measured concentration was 264.2 mg enyzme concentrate dry matter/L. The results were reported in nominal concentrations, as a worse-case.

The numbers of immobilised daphnids were recorded for each test and control group after 24 and 48 hours.

No immobilisation was observed following the exposure of Daphnia magna to the test substance at a concentration of 227.9 mg enzyme concentrate dry matter/L. Due to the low toxicity of the test material, the 48-hour EC50 (immobilisation) value of the substance was unable to be calculated. Therefore, the 48-hour EC50 value of the test substance to Daphnia magna was >227.9 mg enzyme concentrate dry matter/L (equivalent to 103.7 mg active enzyme protein/L).

The no-observed effect concentration (NOEC) was ≥ 227.9 mg enzyme concentrate dry matter/L (equivalent to ≥ 103.7 mg active enzyme protein/L).

Description of key information

No immobilisation was observed following the exposure of Daphnia magna to the test substance at a concentration of 227.9 mg enzyme concentrate dry matter/L. Due to the low toxicity of the test material, the 48-hour EC50 (immobilisation) value of the substance was unable to be calculated. Therefore, the 48-hour EC50 value of the test substance to Daphnia magna was >227.9 mg enzyme concentrate dry matter/L (equivalent to 103.7 mg active enzyme protein/L).

The no-observed effect concentration (NOEC) was ≥ 227.9 mg enzyme concentrate dry matter/L (equivalent to ≥ 103.7 mg active enzyme protein/L).