(±)-neomenthol

Short-term toxicity to fish

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

short-term toxicity to fish

Type of information:

experimental study

Adequacy of study:

key study

Study period:

Jul 13, 1992 - Jul 17, 1992

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

EU Method C.1 (Acute Toxicity for Fish)

GLP compliance:

yes

Analytical monitoring:

yes

Details on sampling:

No details were provided.

Vehicle:

no

Details on test solutions:

The test item was pestled in a mortar, weighed into water and centrifuged in an Ultra-Turrax to create the test solutions. At all concentrations tested, a certain amount of the test item remained undissolved and was floating on the surface of the test solutions. Therefore, the actual test concentrations were measured daily using gas chromatography.

Test organisms (species):

Danio rerio (previous name: Brachydanio rerio)

Details on test organisms:

Common name: Brachydanio rerio
Strain: Hamilton Buchanan
Source: West-Aquarium (Bad Lauterberg, Germany)
Date of birth: 1992-04-18
Date of shipment: 1992-06-10
Length at study initiation: 2.5 - 3.5 cm
Mortalita during acclimatisation: <2%
Medical pretreatment: None
Water for acclimatisation: Synthetic freshwater (according to ISO)

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

96 h

Post exposure observation period:

not applicable

Hardness:

14.1 °dH

Test temperature:

Test temperature values ranged from 21.4 to 22.5 °C during the study. A small decrease in test temperatures during the study period (about 1 °C in most cases) was observed in most of the experiments.

pH:

pH values ranged from 7.1 to 8.0 °C during the study.

Dissolved oxygen:

Dissolved oxygen values ranged from 8.1 to 10.4 mg/L during the study, and oxygen saturation values ranged from 93.4 to 120.0%.

Salinity:

no data

Nominal and measured concentrations:

Nominal test concentrations: 7.8, 11, 16, 22, and 31 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: test aquaria with 300 x 135 x 200 mm, containing 5 L test medium
- Aeration: Yes

TEST MEDIUM / WATER PARAMETERS
- Dilution water: Synthetic freshwater (ISO)
- Controls: Synthetic freshwater (ISO)
- Solubilizing aid: Treatment with an Ultra-Turrax

OTHER TEST CONDITIONS
- Photoperiod: 16 h light / 8 h darkness per day

EFFECT PARAMETERS MEASURED (with observation intervals if applicable)

Assesessed during the experiment at 0, 24, 48, 72, and 96 h:
- Abiotic parameters: Temperature (°C), dissolved oxygen (mg/L), oxygen saturation (% ), pH
- Outer appearance and behaviour of the test animals
- Mortality

Assesessed after death during the experiment or sacrification after termination of the experiment:
- Body weight and length of the test animals

TEST CONCENTRATIONS
- Nominal test concentrations: 7.8, 11, 16, 22, and 31 mg/L
- Actual test concentrations were measured daily using gas chromatography

Reference substance (positive control):

no

Duration:

96 h

Dose descriptor:

LC0

Effect conc.:

13.2 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

dissolved

Basis for effect:

mortality (fish)

Key result

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

15.6 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

dissolved

Basis for effect:

mortality (fish)

Remarks on result:

other: as geom. mean of LC0 and LC100 as determined

Duration:

96 h

Dose descriptor:

LC100

Effect conc.:

18.4 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

dissolved

Basis for effect:

mortality (fish)

Details on results:

no further details were provided

Results with reference substance (positive control):

not applicable

Reported statistics and error estimates:

no data

Sublethal observations / clinical signs:

Table 1 Abiotic parameters

Control
Time (h)	0	24	48	72	96
Temperature (°C)	21.5	21.4	21.1	21.1	21.0
Dissolved oxygen (mg/L)	8.6	8.3	9.4	8.1	9.9
Oxygen saturation (%)	99.9	96.3	108.4	93.4	114.1
pH	7.9	7.8	7.1	7.7	7.7
at 7.8 mg/L
Time (h)	0	24	48	72	96
Temperature (°C)	22.3	21.4	21.1	21.1	21.2
Dissolved oxygen (mg/L)	8.7	8.4	10.2	8.7	8.8
Oxygen saturation (%)	102.5	97.4	117.6	100.3	101.7
pH	7.9	7.5	7.4	7.3	7.4
at 11 mg/L
Time (h)	0	24	48	72	96
Temperature (°C)	22.4	21.5	21.1	21.1	21.3
Dissolved oxygen (mg/L)	8.6	8.5	10.4	8.8	8.7
Oxygen saturation (%)	101.5	98.7	120.0	101.5	100.7
pH	8.0	7.5	7.6	7.3	7.5
at 16 mg/L
Time (h)	0	24	48	72	96
Temperature (°C)	22.3	21.5	21.2	21.1	21.4
Dissolved oxygen (mg/L)	8.6	8.6	10.3	8.7	8.5
Oxygen saturation (%)	101.3	99.9	119.1	100.3	98.6
pH	7.9	7.6	7.4	7.4	7.5
at 22 mg/L
Time (h)	0	24	48	72	96
Temperature (°C)	22.5	21.5	21.2	21.2	NA
Dissolved oxygen (mg/L)	8.5	8.7	10.6	8.9	NA
Oxygen saturation (%)	100.5	101.0	122.5	102.9	NA
pH	7.8	7.6	7.7	7.6	NA
at 31 mg/L
Time (h)	0	24	48	72	96
Temperature (°C)	22.4	21.3	NA	NA	NA
Dissolved oxygen (mg/L)	8.4	8.4	NA	NA	NA
Oxygen saturation (%)	99.2	97.2	NA	NA	NA

NA = not assessed

Table 2. Mortality

 No mortality within 96 h was observed in control animals and at concentrations of the test item of 7.8, 11, and 16 mg/L.

At 22 mg/L
Time (h)	2		24	48	72	96
absolute number of deaths	0		5	0	5	NA
cumulative number of deaths	0		5	5	10	NA
cumulative number of deaths (%)	0		50	50	100	NA
at 31 mg/L
Time (h)	2	24		48	72	96
absolute number of deaths	10	NA		NA	NA	NA
cumulative number of deaths	10	NA		NA	NA	NA
cumulative number of deaths (%)	100	NA		NA	NA	NA

NA = not assessed

Table 3: Outer appearance and behaviour

at 11 mg/L
after 2 h	10 animals
	Sluggish swimming
after 24 h	10 animals
	Sluggish swimming
after 48 h	10 animals
	Sluggish swimming
after 72 h	10 animals
	Sluggish swimming
at 16 mg/L
after 2 h	10 animals
	Sluggish swimming
after 24 h	10 animals
	Sluggish swimming
after 48 h	8 animals
	Sluggish, lethargic swimming
	2 animals
	Sluggish, lethargic swimming, abnormal posture
after 72 h	8 animals
	Sluggish, lethargic swimming
	2 animals
	Sluggish, lethargic swimming, abnormal posture
after 96 h	10 animals
	Sluggish, lethargic swimming
at 22 mg/L
after 2 h	10 animals
	Akinetic, uncontrolled swimming movements upon touching
after 24 h	5 animals
	Akinetic, uncontrolled swimming movements upon touching
after 48 h	5 animals
	Akinetic, uncontrolled swimming movements upon touching

Validity criteria fulfilled:

yes

Conclusions:

In this short-term toxicity test in Brachydanio rerio, the non-lethal concentration 0% (LC0) and the lethal concentration 100% (LC100) were determined as 13.2 and 18.4 mg/L, respectively. The geometric mean between both values (LC50) was calculated as 15.6 mg/L. It was concluded from these data that the test item has to be rated as harmful to fish.

Executive summary:

The short-term toxicity of the test item was assessed in a test in Brachydanio rerio. The test was conducted according to the EU method No. C.1. The test animals were exposed to the test at concentrations of the test item 7.8, 11, 16, 22, and 31 mg/L for up to 96 h and were observed for mortality as well as for changes in their outer appearance and behaviour. Body weight and length of the fish were also recorded. From the mortality data obtained in this study, values for the lethal concentration 0% (LC₀) and the lethal concentration 100% (LC₁₀₀) were determined as 13.2 and 18.4 mg/L, respectively. The geometric mean between both values was calculated as 15.6 mg/L. It was concluded from these data that the test item has to be rated as harmful to fish.

Reference 2

Endpoint:

short-term toxicity to fish

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

Mar 03, 1990 - Apr 17, 1990

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Principles of method if other than guideline:

UBA-Verfahrensvorschlag: "Letale Wirkung beim Zebrabaerbling Brachydanio rerio, LC0, LC50, LC100; 48-96 h" (Mai 1984)
Guideline proposal of the German Federal Environmental Agency (UBA)

GLP compliance:

yes

Analytical monitoring:

yes

Details on sampling:

direct weighted

Vehicle:

no

Details on test solutions:

test medium (synthetic origin, prepared according to ISO)

Test organisms (species):

Danio rerio (previous name: Brachydanio rerio)

Details on test organisms:

- origin: West-Aquarium (Bad Lauterberg, Germany)
- ventilated test system
- loading rate: 10 animals/vessel (3 month old)
- Length: 2.5 to 3.5 cm

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

96 h

Test temperature:

22.3°C

pH:

7.6

Dissolved oxygen:

8.5 mg/l
99.6 %

Nominal and measured concentrations:

Nominal: 7.8, 11, 16, 22 and 31 mg/L
Measured (in mean): 6.4, 9.3, 11.3, 18.7 and 26.2

Duration:

96 h

Dose descriptor:

LC0

Effect conc.:

16 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

22.3 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Duration:

96 h

Dose descriptor:

LC100

Effect conc.:

31 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Details on results:

The fish were exposed to 5 nominal test substance concentrations in the range of 7.8 to 31 mg/l. In all test media, undissolved substance particles remained on the water surface. Analytical measurements revealed that the test substance concentrations decreased below 80 % of the nominal within 96 h, probably due to volatilization.

Validity criteria fulfilled:

yes

Remarks:

- dissolved oxygen concentration remained above 60% of the air-saturation value throughout the exposure period. - No mortality in the controls by the end of the test.

Conclusions:

In a study with fish (Danio rerio) a LC50 of 22.3 mg/L (nominal) after 96 hours is obtained.

Executive summary:

In a study with fish (Danio rerio) a LC50 of 22.3 mg/L (nominal) after 96 hours is obtained. The study was conducted according to Umweltbundesamt (UBA) -Verfahrensvorschlag: "Letale Wirkung beim Zebrabaerbling Brachydanio rerio, Mai 1984.

Description of key information

Danio rerio LC50 (96 h) = 15.6 mg/L (measured); read-across

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Effect concentration:

15.6 mg/L

Additional information

Since no data for the target substance are available, the aquatic toxicity is assessed on the basis of data from structural related menthols (stereo isomers).
The short-term toxicity to fish was investigated for L-menthol (CAS 2216-51-5) and an unspecified menthol isomer mixture (D/L-menthol, CAS 1490-04-6). The studies with both read across substances were carried out as static tests under standard test conditions accordance to GLP. The zebra fish (Danio rerio) was used as test species. In the key study with the source substance L-menthol (CAS 2216-51-5), which was conducted according to the EU method C.1, the test animals were exposed to nominal test concentrations of 7.8, 11, 16, 22, and 31 mg/L for up to 96 h. At all concentrations tested, a certain amount of the test item remained undissolved and was floating on the surface of the test solutions. Therefore, the actual test concentrations were measured daily using gas chromatography and the results are given as measured concentrations. The mortality as well as changes in their outer appearance and behaviour was recorded. Body weight and length of the fish were also recorded. From the mortality data obtained in this study, values for the lethal concentration 0% (LC0, 96 h) and the lethal concentration 100% (LC100, 96 h) were determined to be 13.2 and 18.4 mg/L (measured arithmetic mean), respectively. The geometric mean between both values was calculated to be 15.6 mg/L (LC50, 96 h). This result was confirmed in the supporting study with D/L-menthol (CAS 1490-04-6), where a LC50 of 22.3 mg/L (nominal) after 96 h is obtained.

Based on the results from two structurally related source substances (in accordance to Regulation (EC) No 1907/2006 Annex XI, 1.5) it can be concluded that testing the target substance would result in comparable results.