4-O-α-D-glucopyranosyl-D-glucitol

Toxicity to aquatic algae and cyanobacteria

Link to relevant study record(s)

Reference

Endpoint:

toxicity to aquatic algae and cyanobacteria

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2005

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Alga, Growth Inhibition Test)

Version / remarks:

-1984 followed; reliability scoring based on 2006 guideline

Deviations:

yes

Remarks:

FeCl3 6H2O concentration in medium higher than OECD specification; pH of the control increased by more than 1.5 units during the test

GLP compliance:

yes

Analytical monitoring:

yes

Details on sampling:

- Concentrations: 1500 mg/L (nominal)
- Sampling method: During the exposure, the concentrations of test substance were measured at the beginning of exposure. Test solution was taken to vial and analyzed by high performance liquid chromatography (HPLC).
- Sample storage conditions before analysis: None, analysed immediately

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: Test substance was added directly to medium.
- Controls: The control solution contained only the dilution water.
- Evidence of undissolved material (e.g. precipitate, surface film, etc): No, solubility in dilution water of the test substance is >1500 mg/L (visual observation, measured by M.S.I.).

Test organisms (species):

Pseudokirchneriella subcapitata (previous names: Raphidocelis subcapitata, Selenastrum capricornutum)

Details on test organisms:

TEST ORGANISM
- Common name: Pseudokirchneriella subcapitata
- Strain: ATCC22662
- Source (laboratory, culture collection): American Type Culture Collection
- Method of cultivation: Subculture in Gorham medium under sterile condition. Subculture has been confirmed to be sterile with bacteria test every 6 months.


ACCLIMATION
- Acclimation period: March 4, 2005 to March 8, 2005
- Culturing media and conditions (same as test or not): Same as test
- Any deformed or abnormal cells observed: Not reported

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

72 h

Post exposure observation period:

None

Test temperature:

22.2 to 23.3°C

pH:

7.8 to 10.3

Salinity:

freshwater

Nominal and measured concentrations:

Nominal = 1500 mg/L
Measured = 1490 mg/L at 0 hour; 1420 mg/L at 72 hours

Details on test conditions:

TEST SYSTEM
- Test vessel
- Type (delete if not applicable): Open
- Material, size, headspace, fill volume: 300 mL Erlenmeyer flask, Iwaki (with air-permeable silicon stopper); fill volume 100 mL
- Initial cells density: 10000 cells/mL
- Control end cells density: 2857800 cells/mL
- No. of vessels per concentration (replicates): 6
- No. of vessels per vehicle control (replicates): 6


GROWTH MEDIUM
- Standard medium used: yes (the medium recommended by the OECD Guideline for Testing Chemicals No. 201 was used after sterile filtration (0.22 µm).
H3BO3: 0.185 mg/L
MnCl2 4H2O: 0.415 mg/L
ZnCl2: 0.003 mg/L
FeCl3 6H2O: 0.08 mg/L
Na2EDTA 2H2O: 0.1 mg/L
CoCl2 6H2O: 0.0015 mg/L
Na2MoO4 2H2O: 0.007 mg/L
CuCl2 2H2O: 0.00001 mg/L
CaCl2 2H2O: 18 mg/L
NH4Cl: 15 mg/L
KH2PO4: 1.6 mg/L
NaHCO3: 50 mg/L
MgCl2 6H2O: 12 mg/L
MgSO4 7H2O: 15 mg/L


TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Same as growth medium
- Total organic carbon: Not reported
- Particulate matter: Not reported
- Metals: Not reported
- Pesticides: Not reported
- Chlorine: Not reported
- Alkalinity: Not reported
- Ca/mg ratio: Not reported
- Conductivity: Not reported
- Culture medium different from test medium: No



OTHER TEST CONDITIONS
- Sterile test conditions: Yes
- Adjustment of pH: Not adjusted
- Photoperiod: Continuous
- Light intensity and quality:4000 lux (±20%, at the surface of the test solutions)


EFFECT PARAMETERS MEASURED (with observation intervals if applicable)
- Determination of cell concentrations: electronic particle counter (CDA-500), and hemacytometer, and microscope.


TEST CONCENTRATIONS
- Range finding study: Yes
- Test concentrations: 1.00, 10.0, 100, 1000 mg/L
- Results used to determine the conditions for the definitive study:
Concentration (mg/L) - Growth relative to the control after 72 hours (%)
control - 100
1.00 - 133
10.0 - 154
100 - 147
1000 - 153

Reference substance (positive control):

yes

Remarks:

Potassium dichromate

Key result

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

> 1 490 mg/L

Nominal / measured:

meas. (initial)

Conc. based on:

test mat.

Basis for effect:

growth rate

Key result

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

> 1 040 mg/L

Nominal / measured:

meas. (initial)

Conc. based on:

act. ingr.

Basis for effect:

growth rate

Key result

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

>= 1 490 mg/L

Nominal / measured:

meas. (initial)

Conc. based on:

test mat.

Basis for effect:

growth rate

Key result

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

>= 1 040 mg/L

Nominal / measured:

meas. (initial)

Conc. based on:

act. ingr.

Basis for effect:

growth rate

Key result

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

> 1 490 mg/L

Nominal / measured:

meas. (initial)

Conc. based on:

test mat.

Basis for effect:

biomass

Key result

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

> 1 040 mg/L

Nominal / measured:

meas. (initial)

Conc. based on:

act. ingr.

Basis for effect:

biomass

Key result

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

>= 1 490 mg/L

Nominal / measured:

meas. (initial)

Conc. based on:

test mat.

Basis for effect:

biomass

Key result

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

>= 1 040 mg/L

Nominal / measured:

meas. (initial)

Conc. based on:

act. ingr.

Basis for effect:

biomass

Details on results:

- Exponential growth in the control (for algal test): yes
- Observation of abnormalities (for algal test): In all test concentration groups, color of test cultures observed with naked eye showed a tendency to get more greenish with the passage of time. By the microscopic observation at the end of exposure, in concentration group at 1500 mg/L neither unusual cell shape of algae (concentration, expansion, damaged cell, etc.) nor agglutination was observed, and the algae looked normal compared with the control.
- Any observations (e.g. precipitation) that might cause a difference between measured and nominal values: No suspended solids, floating solids, precipitation or oily substance was found in all test solutions. All test solutions were colorless. There was no significant matter that may have affected the reliability of the test results.

Results with reference substance (positive control):

Growth inhibition test of a reference substance has been conducted every 6 months. 72-hour 50% growth inhibition concentration by comparison of areas under the growth curves (EbC50) since November 1996 was as follows: average ±standard deviation: 0.431 ± 0.0719 mg/L, n=16; minimum value - maximum value = 0.285 to 0.543 mg/L

Reported statistics and error estimates:

Statistical analyses were performed using Yukms Statlight #3 software (Yukms Corp., Tokyo), and all test of significance were at α=0.05.

Validity criteria fulfilled:

yes

Conclusions:

The toxicity of maltitol to the green algae, Pseudokirchneriella subspicata, was determined as 72-NOEC (growth rate and biomass) ≥ 1040 mg/L (active ingredient, measured initial concentration). So Maltitol shows no adverse effect to Pseudokirchneriella subspicata and it is not classified for its toxicity according to CLP criteria.

Executive summary:

The toxicity of maltitol to the green algae, Pseudokirchneriella subspicata, was determined according to the OECD guideline 201 and in compliance with GLP.

6 replicates containing an initial concentration of 10000 cells/ml were exposed to the test item Maltitol at the nominal concentration of 1500 mg/l in a static test. The concentration of the test substance was measured by high performance liquid chromatography (HPLC). The measured concentration was 1490 mg/L test material and 1040 mg/L active ingredient.

The growth of algae in the controls was exponential and satisfies the quality criteria. All test solutions were colorless however microscopic observation at the end of exposure demonstrated that the algae looked normal compared with the control.

No inhibition of algae growth was observed during the exposure. The toxicity of Maltitol to green algae was determined as 72h-NOEC (growth rate and biomass) ≥ 1040 mg/L (active ingredient, measured initial concentration). So maltitol shows no adverse effect to the green algae and it is not classified for its aquatic toxicity according to CLP criteria.

The algal toxicity study is classified as acceptable, and satisfies the guideline requirements of OECD 201.

Description of key information

The toxicity of maltitol to the green algae, Pseudokirchneriella subspicata, was determined as 72 -NOEC (growth rate and biomass) ≥ 1040 mg/L (active ingredient, measured initial concentration). So Maltitol shows no adverse effect to Pseudokirchneriella subspicata and it is not classified for its aquatic toxicity according to CLP criteria.

Key value for chemical safety assessment

EC10 or NOEC for freshwater algae:

1 040 mg/L

Additional information

The toxicity of maltitol to the green algae,Pseudokirchneriella subspicata, was determined according to the OECD guideline 201 and in compliance with GLP.

6 replicates containing an initial concentration of 10000 cells/ml were exposed to the test item Maltitol at the nominal concentration of 1500 mg/l in a static test. The concentration of the test substance was measured by high performance liquid chromatography (HPLC). The measured concentration was 1490 mg/L test material and 1040 mg/L active ingredient.

The growth of algae in the controls was exponential and satisfies the quality criteria. All test solutions were colorless however microscopic observation at the end of exposure demonstrated that the algae looked normal compared with the control.

No inhibition of algae growth was observed during the exposure. The toxicity of Maltitol to green algae was determined as 72h-NOEC (growth rate and biomass) ≥ 1040 mg/L (active ingredient, measured initial concentration). So maltitol shows no adverse effect to the green algae and it is not classified for its aquatic toxicity according to CLP criteria.