Xanthan lyase

Short-term toxicity to fish

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

short-term toxicity to fish

Type of information:

read-across based on grouping of substances (category approach)

Adequacy of study:

key study

Study period:

1995-02-09 to 1995-08-30

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Justification for type of information:

Read-across approach has been applied, as Xanthan lyase has not been tested in a short-term toxicity study in fish, but due to the similarity between the two enzymes, similar results are expected for Xanthan lyase.

Qualifier:

according to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

Deviations:

yes

Remarks:

change of study monitor in april 1995

GLP compliance:

yes (incl. QA statement)

Remarks:

Certificate included in study report

Analytical monitoring:

yes

Details on sampling:

- Concentrations: 0 and 94.7 mg enzyme concentrate dry matter/L
- Sampling method: Duplicate samples from freshly prepared test media of the control and from the test concentration of 94.7 mg enzyme concentrate dry matter/L were taken at the start of the test, after 24h just after the first test medium renewal and at the end of the test at 96h.
- Sample storage conditions before analysis: Samples were stored deep-frozen at -20°C

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method:The test medium was prepared by dissolving a weighed amount of the test substance directly in the test water in the aquarium. The test media was prepared just before introduction of fish.
- Controls: test water

Test organisms (species):

other: Oncorhynchus mykiss Walbaum

Details on test organisms:

TEST ORGANISM
- Common name: Rainbow trout
- Strain: Oncorhynchus mykiss Walbaum
- Source: Forellenhof Fredelsloh, Moringen, Germany
- Length at study initiation (length definition, mean, range and SD): 5.5 ± 0.11 cm
- Weight at study initiation (mean and range, SD): 2.0 ± 0.15 g

ACCLIMATION
- Acclimation period: 12 weeks
- Type and amount of food: commercial trout diet (Alleinfutter für Forellenbrut, Aminostart (extr.), Kraftfutterwerk Wesel GmbH, Wesel, Germany)
- Health during acclimation (any mortality observed): At least during the last three weeks prior to the start of the test no fish diet in the test fish batch

Test type:

semi-static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

96 h

Hardness:

2.10 mmol/L (= 210 mg/L as CaCO3)

Test temperature:

13.1 - 14.6 °C

pH:

7.7 - 8.8

Dissolved oxygen:

8.1-10.4 mg/L

Nominal and measured concentrations:

nominal: 0 and 100 mg/L
measured: fresh samples were between 95.2 and 107.9% of the nominal value
test media taken at the end of the 24 hour renewal periods were between 90.2 and 91.2 % of the nominal value

Details on test conditions:

TEST SYSTEM
- Test vessel: aquarium
- Fill volume: 30 L test medium
- Aeration: slightly
- Renewal rate of test solution (frequency/flow rate): 24 hours
- No. of organisms per vessel: 7
- No. of vessels per concentration (replicates): 1
- No. of vessels per control (replicates): 1


TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: drinking water of the community Rossdorf; before use the total hardness was reduced in the laboratories of RCC and the water filtered through an activated carbon filter.
- Alkalinity: 4.60 mmol/L


OTHER TEST CONDITIONS
- Photoperiod: 16 hours light per day,
- Light intensity: appr. 50 - 300 Lux

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : Fish were observed after 2, 24, 48, 72 and 96 hours test duration for symptoms of intoxication and mortality.

TEST CONCENTRATIONS
- Range finding study
- Results used to determine the conditions for the definitive study: yes

Reference substance (positive control):

no

Key result

Duration:

96 h

Dose descriptor:

NOEC

Effect conc.:

94.7 mg/L

Nominal / measured:

meas. (not specified)

Conc. based on:

test mat.

Remarks:

enyzme concentrate dry matter

Basis for effect:

mortality (fish)

Details on results:

- Behavioural abnormalities: no
- Mortality of control: 0
- Other adverse effects control: no
- Abnormal responses: no

Validity criteria fulfilled:

not specified

Conclusions:

The No-observed-effect concentration for alpha-amylase was the highest exposure concentration of 94.7 mg enzyme concentrate dry matter/L corresponding to 58.3 mg active enzyme protein/L.

Executive summary:

The acute toxicity of alpha-amylase to Rainbow Trout (Oncorhynchus mykiss) was determined in a 96‑hour semi-static test with a daily test medium renewal according to the OECD Guideline No. 203 and in compliance with GLP. 

A limit test was performed to demonstrate that the test substance has no toxic effect on the test animals up to the concentration of 94.7 mg enzyme concentrate dry matter/L corresponding to 58.3 mg active enzyme protein (aep)/L. The analysis of the exposure concentrations revealed that the test substance concentrations were within the range of 80 to 120% of the nominal value.

The 96h NOEC was determined to be 94.7 mg enzyme concentrate dry matter/L, corresponding to 58.3 mg aep/L. The 96h LC50 value could not be determined due to the absence of toxicity of the test substance but is clearly higher than 94.7 mg enzyme concentrate dry matter/L (58.3 mg aep/L).

Reference 2

Endpoint:

short-term toxicity to fish

Type of information:

read-across based on grouping of substances (category approach)

Adequacy of study:

key study

Study period:

20 December 2005 - 02 November 2006

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Justification for type of information:

Read-across approach has been applied, as Xanthan lyase has not been tested in a short-term toxicity study in fish, but due to the similarity between the two enzymes, similar results are expected for Xanthan lyase.

Qualifier:

according to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Details on sampling:

- Concentrations: Range finding test used concentrations 1.04, 10.4, 103.6 and 227.9 mg enzyme concentrate dry matter/L. The definitive test concentration was 227.9 mg enzyme concentrate dry matter/L.
- Sampling method: Triplicate samples (5mL) of media were taken from the control and each test vessel at 0 and 72 hours (fresh media) and at 24 and 96 hours (expired media) for analysis.
- Sample storage conditions before analysis: frozen

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 31.68 g was dispersed directly in 20 litres of diluent water to give the nominal test concentration of 227.9 mg enzyme concentrate dry matter/L.
- Controls: Medium

Test organisms (species):

Oncorhynchus mykiss (previous name: Salmo gairdneri)

Details on test organisms:

TEST ORGANISM
- Common name: Rainbow trout
- Strain: Oncorhynchus mykiss
- Source: Westacre Trout Farm, Norfolk, UK
- Length at study initiation (length definition, mean, range and SD): mean standard length: 4.9cm (SD = 0.34cm)
- Weight at study initiation (mean and range, SD): mean weight: 1.89g (SD = 0.45g)
- Feeding during test: no

ACCLIMATION
- Acclimation period: 12 day
- Acclimation conditions (same as test or not):The stock of fish was obtained from the supplier on 15 February 2006 and acclimatised to test conditions from this date. Holding water temperature remained within the range 13 to 14°C and dissolved oxygen within the range 8.3 to 9.2 mg O2/L in the 12-day period immediately before the study with a 16 hour light: 8 hour dark photoperiod.
- Type and amount of food: The fish were fed 2% of their body weight daily with commercial fry pellet.
- Feeding frequency: daily until 24 hours before exposure, but food was not given during the 24-hour period immediately before exposure or during the exposure period itself.
- Health during acclimation (any mortality observed): No mortality

Test type:

semi-static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

96 h

Hardness:

147-173 mg CaCO3/L

Test temperature:

13-14°C

pH:

7.0-7.8

Dissolved oxygen:

7.1-8.2 mg O2/L

Nominal and measured concentrations:

range finding: nominal: 1.04, 10.4, 103.6 and 227.9 mg enzyme concentrate dry matter/L; no measurements
limit test:
nominal concentrations: 0 and 227.9 mg enzyme concentrate dry matter/L
Measured concentrations:
Mean: 250.7 mg enzyme concentrate dry matter/L (Measured concentrations ranged from 117.5% of nominal at 0 hours and 24 hours, 102.9% of nominal at 72 hours and 102.5% of nominal at 96 hours). The test substance could not be detectet in control samples.

Details on test conditions:

TEST SYSTEM
- Test vessel: glass aquaria
- Material, size, headspace, fill volume: glass, size: 24x45x24 cm, fill volume: 20 litres
- Aeration: supplementary aeration through narrow bore glass tubes.
- Renewal rate of test solution (frequency/flow rate): daily
- No. of organisms per vessel: 10
- No. of vessels per concentration (replicates): 1
- No. of vessels per control (replicates): 1
- Biomass loading rate: 0.95 g bodyweight/L

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: The water used for the study was laboratory tap water filtered, dechlorinated and softened by passage through a Vivendi water purification system. The water was passed through a highgrade activated carbon filter to remove chlorine and any organic contaminants. A proportion of the supply was then passed through a water softener before final reverse osmosis (RO) treatment to produce a highly purified water supply. These two supplies were then remixed in the appropriate ratio to give a laboratory supply with the desired water hardness
- Total organic carbon: 5 mg/L
- Chlorine: 0.01-0.05 mg/L (free chlorine 0.00 - 0.02 mg/L)
- Conductivity: 500 uS/cm
- Culture medium different from test medium: No

OTHER TEST CONDITIONS
- Photoperiod: 16 hours light: 8 hours dark

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : The criteria of death employed in this study were (i) absence of respiratory movement and (ii)absence of response to physical stimulation of the caudal peduncle. In addition to observations on mortality at 15 minutes and 2, 4, 24, 48, 72 and 96 hours, subjective assessments were made on the type and incidence of sub-lethal effects compared with control fish.

TEST CONCENTRATIONS
- Spacing factor for test concentrations: limit test
- Range finding study
- Test concentrations: 1.04, 10.4, 103.6 and 227.9 mg enzyme concentrate dry matter/L (preliminary test)
- Results used to determine the conditions for the definitive study: results from range finding study were used.

Reference substance (positive control):

no

Key result

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

> 227.9 mg/L

Nominal / measured:

nominal

Conc. based on:

other:

Remarks:

enzyme concentrate dry matter

Basis for effect:

mortality (fish)

Key result

Duration:

96 h

Dose descriptor:

NOEC

Effect conc.:

227.9 mg/L

Nominal / measured:

nominal

Conc. based on:

other: enzyme concentrate dry matter

Basis for effect:

other: visual observation for lethal and treatment-related effects

Details on results:

- Behavioural abnormalities: no
- Observations on body length and weight: no
- Other biological observations: no
- Mortality of control: no
- Other adverse effects control: no
- Abnormal responses: no
- Any observations (e.g. precipitation) that might cause a difference between measured and nominal values: no
- Effect concentrations exceeding solubility of substance in test medium: no

Validity criteria fulfilled:

not specified

Conclusions:

No mortality was observed following the exposure of rainbow trout 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 96-hour LC50 value of the substance was unable to be calculated. Therefore, the 96-hour LC50 value for the test substance with rainbow trout was determined to be > 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:

A study was performed to assess the acute toxicity of Glucoamylase, batch PPY 24900 to rainbow trout (Oncorhynchus mykiss) under semi-static conditions.

The study was conducted in accordance with OECD and EC guidelines, and in compliance with GLP. A group of ten juvenile fish were exposed to a single test concentration, nominally 227.9 mg enyzme concentrate dry matter/L of Glucoamylase, batch PPY 24900 dispersed in dechlorinated water.

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. Measured concentrations ranged from 117.5% of nominal at 0 hours and 24 hours, 102.9% of nominal at 72 hours and 102.5% of nominal at 96 hours). The test substance could not be detectet in control samples. 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 250.7 mg enzyme concentrate dry matter/L. The results were based on nominal concentrations as a worse-case.

Observations were made on the numbers of dead fish and the incidence of sub-lethal effects after 15 minutes and 2, 4, 24, 48, 72 and 96 hours exposure.

No mortality was observed following the exposure of rainbow trout 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 96-hour LC50 value of the substance was unable to be calculated. Therefore, the 96-hour LC50 value for the test substance with rainbow trout was determined to be > 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).

Reference 3

Endpoint:

short-term toxicity to fish

Type of information:

read-across based on grouping of substances (category approach)

Adequacy of study:

key study

Study period:

4 February 1992 - 19 August 1992

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Justification for type of information:

Read-across approach has been applied, as pectate lyase has not been tested in a short-term toxicity study in fish, but due to the similarity between the two enzymes, similar results are expected for Xanthan lyase.

Qualifier:

according to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Remarks:

certificate included in study report

Analytical monitoring:

no

Details on sampling:

- Concentrations: Test concentrations were 312.3, 546.6, 976.0, 1756.8, 3123.2 mg enzyme concentrate dry matter/L.
- Sampling method: none
- Sample storage conditions before analysis: N/A

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: A sample of the test material was dispersed in 20 litres of laboratory tap water to give the nominal test concentrations.
- Controls: Medium ( laboratory tap water)

Test organisms (species):

Oncorhynchus mykiss (previous name: Salmo gairdneri)

Details on test organisms:

TEST ORGANISM
- Common name: Rainbow trout
- Strain: Oncorhynchus mykiss
- Source: Westacre Trout Farm, Norfolk, UK
- Length at study initiation (length definition, mean, range and SD): mean standard length: 4.4cm (SD = 0.6cm)
- Weight at study initiation (mean and range, SD): mean weight: 0.9g (SD = 0.41g)
- Feeding during test: no

ACCLIMATION
- Acclimation period: 7 days
- Acclimation conditions (same as test or not):The stock of fish was obtained from the supplier on 1 May 1992 and acclimatised to test conditions from this date. Holding water temperature remained at 14 +/-1 °C and dissolved oxygen >10.1 mg O2/l in the 7-day period immediately before the study.
- Photoperiod: 16h light : 8h dark
- Type and amount of food: The fish were fed with commercial trout pellets.
- Feeding frequency: daily until 24 hours before exposure
- Health during acclimation (any mortality observed): no

Test type:

semi-static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

96 h

Hardness:

150-200 mg CaCO3/L

Test temperature:

14 +/- 1 °C

pH:

6.8-7.8

Dissolved oxygen:

9.2-10.3 mg O2/L

Nominal and measured concentrations:

Nominal concentrations: 312.3, 546.6, 976.0, 1756.8, 3123.2 mg enzyme concentrate dry matter/L.

Details on test conditions:

TEST SYSTEM
- Test vessel: glass aquaria
- Material, size, headspace, fill volume: glass, size: fill volume: 20 liters
- Aeration: supplementary aeration via narrow bore glass tubes.
- Renewal rate of test solution (frequency/flow rate): daily
- No. of organisms per vessel: 10
- No. of vessels per concentration (replicates): 1
- No. of vessels per control (replicates): 1
- Biomass loading rate: 0.45 g bodyweight/L

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: The water used for the study was laboratory tap water dechlorinated by passage through activated carbon and softened by reverse osmosis.
- Total organic carbon: 3.9 mg/L
- Chlorine: 0.23 mg/L
- Conductivity:
- Culture medium different from test medium: no


OTHER TEST CONDITIONS
- Photoperiod: 16 hours light: 8 hours dark

EFFECT PARAMETERS MEASURED (with observation intervals if applicable): The criteria of death employed in this study were (i) absence of respiratory movement and (ii) absence of response to physical. Mortality observations were collected at 3, 6, 24, 48, 72 and 96 hours after exposure start.

TEST CONCENTRATIONS
- Spacing factor for test concentrations: 1.8x
- Range finding study
- Test concentrations: 312.3, 546.6, 976.0, 1756.8, 3123.2 mg enzyme concentrate dry matter/L.
- Results used to determine the conditions for the definitive study:

Reference substance (positive control):

no

Key result

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

1 171.2 mg/L

Nominal / measured:

nominal

Conc. based on:

other: enzyme concentrate dry matter

Basis for effect:

mortality (fish)

Key result

Duration:

96 h

Dose descriptor:

NOEC

Effect conc.:

546.6 mg/L

Nominal / measured:

nominal

Conc. based on:

other: enzyme concentrate dry matter

Basis for effect:

behaviour

Remarks:

lethargy

Details on results:

- Behavioural abnormalities: yes
- Observations on body length and weight: not recordet
- Other biological observations: no
- Mortality of control: no
- Other adverse effects control: no
- Abnormal responses: no
- Any observations (e.g. precipitation) that might cause a difference between measured and nominal values: no
- Effect concentrations exceeding solubility of substance in test medium: no

Validity criteria fulfilled:

not specified

Conclusions:

The exposure of Rainbow trout to Peroxidase, batch SP491 gave the following results:
72hr LC50 = 1268.8 enzyme concentrate dry matter/L. At the end of the test, the 96hr LC50 = 1171.2 mg enzyme concentrate dry matter/L (equivalent to 331.2 mg active enzyme protein)/L. The NOEC was 546.6 mg enzyme concentrate dry matter/L.

Executive summary:

An acute toxicity test to rainbow trout (Oncorhynchus mykiss) was conducted to determine the effect of Peroxidase SP 491 on fish. The study was conducted in accordance with OECD and EC guidelines, and in compliance with GLP.

The test substance was acutely toxic to rainbow trout at concentrations above 546.6 mg enzyme concentrate dry matter/L since mortality and lethargy was observed during the 96 hour exposure period.

The nominal exposure concentrations were maintained by daily medium renewal.

No mortalities were observed in the control group.

The following results are expressed in terms of the mean measured concentration:

72hr LC50 = 1268.8 enzyme concentrate dry matter/L.
96hr LC50 = 1171.2 mg enzyme concentrate dry matter/L (equivalent to 331.2 mg active enzyme protein)/L.
NOEC = 546.6 mg enzyme concentrate dry matter/L.

 

Reference 4

Endpoint:

short-term toxicity to fish

Type of information:

read-across based on grouping of substances (category approach)

Adequacy of study:

key study

Study period:

28 March 2011 - 13 March 2012

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Remarks:

Reliability 1

Justification for type of information:

Read-across approach has been applied, as Xanthan lyase has not been tested in a short-term toxicity study in fish, but due to the similarity between the two enzymes, similar results are expected for Xanthan lyase.

Qualifier:

according to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

Deviations:

no

GLP compliance:

yes

Analytical monitoring:

yes

Details on sampling:

- Concentrations: 4.7, 10.3, 22.8, 50.1, 110.1 mg enzyme concentrate dry matter/L
- Sampling method: Three, mid-vessel samples (15mL) of media were taken from the control and test vessels at 0 and 72 hours (fresh media) and at 24 and 96 hours (expired media) for analysis.
- Sample storage conditions before analysis: Frozen until analysis

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: The test substance, which is stored frozen, was defrosted overnight at approximately 4°C. Once defrosted the sample will be gently mixed before weighing to ensure homogeneity. The test substance was dispersed in 1L diluent water (17.6g, 7.9g, 3.65g, 1.65g or 0.750 g) in a volumetriuc flask. The contents of each were shaken vigorousley before being poured into a test vessel (glass aquarium) and the volume adjusted to 20 litres with diluent water. Test media were freshly prepared on each day of the definitive test.
- Controls: Medium

Test organisms (species):

Oncorhynchus mykiss (previous name: Salmo gairdneri)

Details on test organisms:

TEST ORGANISM
- Common name: Rainbow trout
- Strain: Oncorhynchus mykiss
- Source: Commercial fish farm in the UK and were reared at the farm from eggs hatched in July 2011
- Length at study initiation (mean) : 4.92 cm
- Weight at study initiation (mean wet weight): 1.05g
- Feeding during test: no

ACCLIMATION
- Acclimation period: 14 days
- Acclimation conditions (same as test or not): The stock of fish were held in aerated supply of diluent water under flow -through conditions until required. During the 14-day period prior to the definitive test, temperatures remained within the range 14.2 to 14.4°C, pH values within the range 7.90 to 7.99, dissolved oxygen concentrations within the range 82 to 95% air saturation value (ASV) and total hardness within the range 153 to 175 mg/L as CaCO3.
- Type and amount of food: Commercial fish food (TROUW (UK) Ltd., Nutra Fry 02); Fish were fed an amount equivalent to between 1.5 and 3% of the total wet-weight of fish in the holding tank.
- Feeding frequency: daily
- Health during acclimation (any mortality observed): No medication given during the holding period and no mortality occured during the 14 days before the efinitive test.

Test type:

semi-static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

96 h

Hardness:

121-152 mg/L as CaCO3

Test temperature:

12.8 - 14.2°C

pH:

7.89 - 8.59

Dissolved oxygen:

77-108 % ASV

Salinity:

-

Nominal and measured concentrations:

nominal: 0, 4.7, 10.3, 22.8, 50.1 and 110.1 mg enzyme concentrate dry matter/L
In samples of freshly prepared media, enzyme recovery ranged between 67 and 102% of the nominal value and in samples of expired (24-hour-old) media between 71 and 110% of the nominal value.

Details on test conditions:

TEST SYSTEM
- Test vessel: glass aquarium
- Material, fill volume, depth: glass, 20L, 18.5 cm
- Aeration: yes
- Renewal rate of test solution (frequency): daily
- No. of organisms per vessel: 7
- No. of vessels per concentration (replicates): 1
- No. of vessels per control (replicates): 1
- Biomass loading rate: 0.369 g bodyweight/litre

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Filtered dechlorinated tap water blended with tap water that had been softened and subsequently treated by reverse osmosis to a hardness of 150-200 mg/L as CaCO3.
- Total organic carbon: 0.92 mg/L
- Particulate matter: <3.0 mg/L

- Organochlorine pesticides: < 0.04 µg/L
- Chloride: 13 mg/L
- Conductivity: 300 µS/cm (20°C)
- Culture medium different from test medium: no
- Intervals of water quality measurement: Analysis of a sample taken in March 2011

OTHER TEST CONDITIONS
- Adjustment of pH: no

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : Observations on mortality and subjective assessments on the incidence and type of sub-lethal effects compared with control fish were made at approximately 2,4, 24, 48, 72 and 96 hours.
The criteria of death em

TEST CONCENTRATIONS
- Spacing factor for test concentrations: 2
- Justification for using less concentrations than requested by guideline:
- Range finding study
- Test concentrations: 1.1, 11.0 and 110.1 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:

96 h

Dose descriptor:

LC50

Effect conc.:

> 110.1 mg/L

Nominal / measured:

nominal

Conc. based on:

other: enzyme concentrate dry matter

Basis for effect:

mortality (fish)

Key result

Duration:

96 h

Dose descriptor:

NOEC

Effect conc.:

50.1 mg/L

Nominal / measured:

nominal

Conc. based on:

other: enzyme concentrate dry matter

Basis for effect:

mortality (fish)

Details on results:

- Behavioural abnormalities: At 110.1 mg enzyme concentrate dry matter/L lethargy was observed with fish to be quiescent both at the surface of the media and at the base of the test vessel. Incidences of aggression were observed at lower exposure concentrations but are not considered to be a treatment related effect.
- Mortality of control: no
- Other adverse effects control: no

Validity criteria fulfilled:

not specified

Conclusions:

Under the conditions of the test, Cellulase, batch PPC31776 was not found to be acutely toxic to rainbow trout (Oncorhynchus mykiss). Consequently, the 96-hour LC50 value for Cellulase could not be calculated and must be >110.1 mg enzyme concentrate dry matter/L (equivalent to 52.1 mg active enzyme protein/L). The "no-observed effect concentration" was 50.1 mg enzyme concentrate dry matter/L (equivalent to 23.7 mg active enzyme protein/L).

Executive summary:

A study was performed to assess the acute toxicity of Cellulase, batch PPC31776 to rainbow trout (Oncorhynchus mykiss) under semi-static conditions with daily renewal of the media.

The study was conducted in accordance with EC Methods for Determination of Ecotoxicity, Annex to Directive 92/69/EEC (O.J. No. L383A, 1992) Part C, Method 1 “Acute Toxicity For Fish” and the OECD Guideline for Testing of Chemicals No. 203 “Fish, Acute Toxicity Test” (1992).

Groups of seven juvenile fish were exposed to Cellulase, dispersed in water at nominal concentrations of 4.7, 10.3, 22.8, 50.1 and 110.1 mg enzyme concentrate dry matter/L. The test media were prepared by direct addition of the test substance to water.

At the request of the Sponsor, the test concentrations were verified by analysis of the enzyme concentrations, which was performed at the Sponsor’s laboratory.

Observations of the fish were made after approximately 2, 4, 24, 48, 72 and 96 hours of exposure. After 96 hours, the highest concentration at which no mortality had occurred was 50.1 mg enzyme concentrate dry matter/L (equivalent to 23.7 mg active enzyme protein/L). At 110.1 mg enzyme concentrate dry matter/L (52.1 mg aep/L), mortality was recorded as 14% (one fish) and treatment-related effects were observed.

Based on these findings the following values have been estimated:

96-hour LC50 value: > 110.1 mg enzyme concentrate dry matter/L (equivalent to 52.1 mg aep/L)

“No observed effect concentration”: 50.1 mg enzyme concentrate dry matter/L (equivalent to 23.7 mg active enzyme protein/L).

Description of key information

The toxicity of Xanthan lyase to fish has not been tested, however, a read-across was performed with other enzymes belonging to different enzyme classes, namely alpha amylase, cellulase, glycoamulase, peroxidase and asparaginase.

Alpha-amylase: The No-observed-effect concentration for alpha-amylase was the highest exposure concentration of 94.7 mg enzyme concentrate dry matter/L corresponding to 58.3 mg active enzyme protein/L.
Cellulase: Under the conditions of the test, Cellulase, batch PPC31776 was not found to be acutely toxic to rainbow trout (Oncorhynchus mykiss). Consequently, the 96-hour LC50 value for Cellulase could not be calculated and must be >110.1 mg enzyme concentrate dry matter/L (equivalent to 52.1 mg active enzyme protein/L). The "no-observed effect concentration" was 50.1 mg enzyme concentrate dry matter/L.
Gluco-amylase: No mortality was observed following the exposure of rainbow trout 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 96-hour LC50 value of the substance was unable to be calculated. Therefore, the 96-hour LC50 value for the test substance with rainbow trout was determined to be > 227.9 mg enzyme concentrate dry matter/L (equivalent to >103.7 mg active enzyme protein/L). NOEC was 227.9 mg enzyme concentrate dry matter/L.
Peroxidase: The 96hr LC50 = 1171.2 mg enzyme concentrate dry matter/L (equivalent to 331.2 mg active enzyme protein)/L. The NOEC was 546.6 mg enzyme concentrate dry matter/L.