Pyridoxine hydrochloride

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:

3 to 12 November 1992

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: The test was performed according to OECD Guidelines and in compliance with GLP principles. As the detailed method validation results were not reported, the study is considered reliable with restrictions.

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Deviations:

no

GLP compliance:

yes

Analytical monitoring:

yes

Details on sampling:

Composite samples (about 150 mL in duplicate) of each test concentration were drawn by mixing identical volumes of the test solutions taken from the approximate center of the test vessels. They were taken immediately before exposure and after 48 hours exposure and kept at - 18 ºC to - 22 ºC until analysis.

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
- Method: calculated amounts of the stock solution (200.2 mg test substance with 2000 mL water) to produce the desired test concentrations were homogeneously distributed into the water. The solutions were homogenuous at all test times and test concentrations.

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Strain: Straus 1820
- Source: CIBA-GEIGY Ltd., testing facility
- Age at study initiation: 24 hours before the start of the exposure, reproductive daphnia are separated from the young by sieving all individuals through a 800 µm sieve. This operation is repeated immediately before the exposure and the young (0-24 h of age) are retained for teh test.
- Method of breeding: cultures of daphnia are maintained in glass vessels comtaining approx. 2.5 L of reconstituted water at 20 ± 1 ºC (water is renewed partially 3 times a week). At each renewal the daphnia were fed with a suspension of green algae (Scenedesmus subspicatus) supplemented by a suspension of Tetramin-extract in such quantities that the food is consumed after 24 hours.
- Feeding during test: none

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Hardness:

240 mg CaCO3/L

Test temperature:

21 ºC

pH:

Conc nominal mg/L pH 0 h pH 48h
Blank 7.8 7.7
10 7.6 7.8
18 7.5 7.8
32 7.2 7.8
58 7.1 7.7
100 6.3 7.5

Dissolved oxygen:

98-101 % of the air staurated value (no raw data reported)

Salinity:

Not applicable.

Nominal and measured concentrations:

Nominal: 10, 18, 32, 58, and 100 mg/L
Measured: see table below. The measured concentrations were within ± 20% of nominal concentrations at the start and end of the test. The effect concentrations were reported as nominal concentrations, which is acceptable.

Details on test conditions:

TEST SYSTEM
- Test vessel: Beakers covered with watch glasses
- Material, size, headspace, fill volume: 100 mL solution per beaker
- Aeration: None
- 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: Reconstituted water containing 65 mg NaHCO3, 294 mg CaCl2.2H2O, 123 mg MgSO4.7H2Oand 6 mg KCl in 1000 mL bidistrilled water. The water was aerated with clean air for at least 24 hours before use.

OTHER TEST CONDITIONS
- Adjustment of pH: no data
- Photoperiod: no lighting

EFFECT PARAMETERS MEASURED: immobilization at 24 and 48 hours

TEST CONCENTRATIONS
- Spacing factor for test concentrations: 1.8
- Range finding study: performed but not reported

Reference substance (positive control):

no

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

In the blank, 5% immobilization was observed after 24 and 48 hours.
5% immobilization was also observed at 10, 18 and 58 mg/L test concentration. No immobilization was observed at 100 mg/L.

Results with reference substance (positive control):

None

Reported statistics and error estimates:

None

Validity criteria fulfilled:

yes

Conclusions:

The 48h-EC50 for immobilization was > 100 mg/L (analytically confirmed nominal concentration).

Executive summary:

In a 48h acute toxicity study conducted according to OECD 202, water fleas (Daphnia magna) were exposed to Pyridoxin-HCl under static conditions at the following nominal concentrations: blank-control, 10, 18, 32, 56, 100 mg/L. Test substance induced no different mobility in reference to the control at any of the concentrations tested. The 48h- LC50 was >100 mg/L based on analytically confirmed nominal concentrations. As the detailed method validation results were not reported, the study is considered to be reliable with restrictions.

Description of key information

In a 48h acute toxicity study conducted according to OECD 202, water fleas (Daphnia magna) were exposed to Pyridoxin-HCl under static conditions at the following nominal concentrations: blank-control, 10, 18, 32, 56, 100 mg/L. Test substance induced no different mobility in reference to the control atany of the concentrations tested.The 48h- LC50 was >100 mg/L based on analytically confirmed nominal concentrations.Asthe detailed method validation results were not reported, the study is considered to be reliable with restrictions.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

100 mg/L