Chymotrypsin

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:

supporting study

Study period:

22-10-2010 to 13-12-2010

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Justification for type of information:

A reliability score of 2 was given since the study was not performed under GLP and the concentrations were not measured, but only given as nominal values.

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Deviations:

no

GLP compliance:

no

Analytical monitoring:

no

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
- Method: Dilution in media (Standard Freshwater ISO 6341).
- Controls: Standard Freshwater ISO6341.
- Evidence of undissolved material (e.g. precipitate, surface film, etc.): No

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Daphnia
- Strain: Daphnia magna Straus
- Source: MicroBioTests Inc. Daphnia magna have been developed by the research teams at the Laboratory for Biological Research in Aquatic Pollution (LABRAP) at the Ghent University in Belgium.
- Age at study initiation (mean and range, SD): less than 24 hours
- Feeding during test: no

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Test temperature:

20-25°C

Nominal and measured concentrations:

4.6, 10, 21, 46, 100 mg TOS/L nominal.

Details on test conditions:

TEST SYSTEM
The test was conducted according to DAPHTOXKIT F MAGNA Crustacean Toxicity Screening Test for Freshwater with a test system supplied by MicroBioTests Inc.
http://www.microbiotests.be/SOPs/Daphtoxkit%20magna%20F%20SOP%20-%20A5.pdf

- Test vessel: The bioassays are conducted in disposable multiwell test plates with 30 test wells.
- Type: closed
- Material, size, headspace, fill volume: 10 mL
- Aeration: The Standard Freshwater (ISO medium) must be aerated for at least 15 minutes prior to using it.
- No. of organisms per vessel: 20 (5 daphnia per well)
- No. of vessels per concentration and control (replicates): Each plate is provided with 4 wells for the controls and 4 wells (A,B,C,D) for each toxicant concentration.

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: ISO medium, formula according to ISO 6341

Composition :
vial 1 : NaHCO3 (129.5 mg - dissolved in 2 L = 67.75 mg/L)
vial 2 : CaCl2.2H2O (588 mg - dissolved in 2 L = 294 mg/L)
vial 3 : MgSO4.7H2O (246.5 mg - dissolved in 2 L = 123.25 mg/L)
vial 4 : KCl (11.5 mg - dissolved in 2 L = 5.75 mg/L)

Reference substance (positive control):

no

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

21 other: mg TOS/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

3.9 mg/L

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

4.6 other: mg TOS/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

0.8 mg/L

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

mobility

Details on results:

Details on results
- Mortality of control: 0
- Other adverse effects control: No
- Abnormal responses: No
- Effect concentrations exceeding solubility of substance in test medium: No
Daphnia were considered to be immobile if they were unable to swim within 15 seconds following gentle touch of the animal with a pin.

Validity criteria fulfilled:

yes

Conclusions:

Chymotrypsin, batch PPA23785 was tested with Daphnia magna for 48 hours at a nominal concentrations up to 100 mg TOS/L. The EC50 value was calculated to be 21 mg TOS/L (3.9 mg aep/L) and NOEC was 4.6 mg TOS/L (0.8 mg aep/L).

Executive summary:

The purpose of this study was to screen chymotrypsin, batch PPA23785 for the test material concentration estimated to immobilise 50% of the Daphnia magna after 24 and 48 hours exposure. DAPHTOXKIT F™ magna was supplied by MicroBioTests Inc. The testing of the chymotrypsin, batch PPA23785 was performed as a screening with a broad range of concentrations 4.6, 10, 21, 46, 100 mg TOS/L. The acceptance criterion for a valid test is that the spontaneous immobility in the control is below or equal to 10%.

Chymotrypsin, batch PPA23785 was tested with Daphnia magna for 48 hours at a nominal concentrations up to 100 mg TOS/L. The EC50 value was calculated to be 21 mg TOS/L (3.9 mg aep/L) and NOEC was 4.6 mg TOS/L (0.8 mg aep/L).

Description of key information

Chymotrypsin, batch PPA23785 was tested with Daphnia magna for 48 hours at a nominal concentrations up to 100 mg TOS/L. The EC50 value was calculated to be 21 mg TOS/L (3.9 mg aep/L) and NOEC was 4.6 mg TOS/L (0.8 mg aep/L).

Chymotrypsin (10R Protease) was tested with Daphnia magna in concentrations 1.5, 6.0, 18, 43 and 98 mg TOS/L.

48-hr EC50 was 15 mg TOS/L (2.8 mg aep/L). No-observed effect concentration was 1.5 mg TOS/L (0.28 mg aep/L).

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

2.8 mg/L