Tetrahydro-4-methyl-2H-pyran

Short-term toxicity to fish

Link to relevant study record(s)

Reference

Endpoint:

short-term toxicity to fish

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2010-02-01 to 2010-02-05

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

Deviations:

no

Qualifier:

according to guideline

Guideline:

other: Fish, Acute Toxicity Test stipulated in the "Testing Methods for New Chemical Substances" of Japan

Version / remarks:

2006

GLP compliance:

yes

Analytical monitoring:

yes

Details on sampling:

- Concentrations: Samples of all concentrations were taken at the start, before and after renewal, and at the end of exposure.

Vehicle:

no

Test organisms (species):

Oryzias latipes

Details on test organisms:

TEST ORGANISM
- Common name: Medaka (Oryzias latipes)
- Strain: Not stated.
- Source: CERI Kurume
- Age at study initiation (mean and range, SD): 13 month.
- Length at test end (determined on control fish) (length definition, mean, range and SD): 2.3 ± 1.2 cm.
- Weight at test end (determined on control fish) (mean and range, SD): 0.11 ± 0.011 g

ACCLIMATION
- Acclimation period: 68 days.
- Acclimation conditions (same as test or not): Yes
- Type and amount of food during acclimation: Feed mixture for carp
- Feeding frequency during acclimation: Once per day. No feeding was done 24 hours before start of experiment.
- Health during acclimation (any mortality observed): No mortality was observed.

Test type:

semi-static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

96 h

Test temperature:

23.2 - 24.0°C (control)
23.4 - 24.0°C (test concentration)

pH:

7.4 - 7.7 (control)
7.3 - 7.6 (test concentration)

Dissolved oxygen:

7.3 - 8.7 (control)
7.3 - 8.7 (test concentration)

Nominal and measured concentrations:

nominal: 0 (control) and 120 mg/L
measured: 0 (control) and 110 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: 7.8 L glass tanks (diameter: 24 cm, depth: 28 cm).
- Type (delete if not applicable): Closed with teflon seat
- Aeration: No.
- Renewal rate of test solution (frequency/flow rate): After 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: tap water
- Total organic carbon: 0.1 mg/L
- Particulate matter: < 1 mg/L
- Metals: Yes, all concentration < 0.0005 mg/L
- Chlorine: 14 mg/L
- Alkalinity: 35 mg/L
- Ca/mg ratio: 3.46
- Culture medium different from test medium: No.

OTHER TEST CONDITIONS
- Adjustment of pH: No.
- Photoperiod: 16-hour light / 8-hour dark
- Light intensity: Room light

EFFECT PARAMETERS MEASURED (with observation intervals if applicable): Mortality

TEST CONCENTRATIONS
- Spacing factor for test concentrations: None.
- Range finding study
- Test concentrations:
Nominal: 0 (control) and 120 mg/L
- Results used to determine the conditions for the definitive study: Yes

Reference substance (positive control):

yes

Remarks:

Copper sulfate pentahydrate

Key result

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

> 120 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

> 110 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Details on results:

Because the mean measured test concentration is within the 20% range of nominal, the key results are based on nominal.

Results with reference substance (positive control):

- Results with reference substance valid? yes
96-hour LC50: 0.54 mgfL. This value was within the stipulated range (mean ± S.D.: 0.13 - 0.96 mg/L) [mean ± S.D. : 0.55 ± 0.21 mg/L (n=44)] to background data in the laboratory.

Sublethal observations / clinical signs:

Table 1: Mortality

Mean measured concentration (mg/L)	Cumulative mortality (%)
	3 hours	24 hours	48 hours	72 hours	96 hours
Control	0	0	0	0	0
110	0	0	0	0	0

Table 2: Dissolved oxygen in test solutions

Mean measured concentration (mg/L)	Dissolved oxygen (%)
	Start	24 hours (old)	48 hours (old)	72 hours	End
Control	8.6	7.3	7.5	7.5	7.7
110	8.4	7.3	7.3	7.4	7.6

Table 3: pH-values in the test solutions

Mean measured concentration (mg/L)	pH-values
	Start	24 hours (old)	48 hours (old)	72 hours	End
Control	7.7	7.4	7.4	7.5	7.4
110	7.7	7.3	7.5	7.5	7.4

Validity criteria fulfilled:

yes

Conclusions:

As no mortality was observed in the 120 mg/L level, the 96-hour LC50 was determined with > 120 mg/L based on nominal concentration.

Executive summary:

The toxicity of the test item Tetrahydro-4-methyl-2H-pyran was examined in a fish acute test according to OECD 203 and under GLP conditions. Individuals of Oryzias latipes (Medaka) were exposed to 0 (control) and 120 mg/L of the test substance, equivalent to 110 mg/L mean measured concentration, for 96 hours. Concentrations were analytically verified via GC-FID. As no mortality was observed in the 120 mg/L level, the 96-hour LC50 was determined with > 120 mg/L based on nominal concentration.

Description of key information

LC50 (96-h) > 120 mg/L based on nominal concentration

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Effect concentration:

120 mg/L

Additional information

The toxicity of the test item Tetrahydro-4-methyl-2H-pyran was examined in a fish acute test according to OECD 203 and under GLP conditions. Individuals of Oryzias latipes (Medaka) were exposed to 0 (control) and 120 mg/L of the test substance, equivalent to 110 mg/L mean measured concentration, for 96 hours. Concentrations were analytically verified via GC-FID. As no mortality was observed in the 110 mg/L level, the 96-hour LC50 was determined with > 120 mg/L based on nominal concentration.