Menthol

Short-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

12/2002

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study

Reason / purpose for cross-reference:

read-across: supporting information

Qualifier:

according to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

Deviations:

no

Principles of method if other than guideline:

Guideline comparable to OECD 202 (Daphnia sp. Acute Immobilisation Test)

GLP compliance:

yes

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source and lot/batch No.of test material: 136

RADIOLABELLING INFORMATION (if applicable): No radiolabelling

Analytical monitoring:

yes

Details on test solutions:

stock solutions were prepared

Test organisms (species):

Daphnia magna

Details on test organisms:

Daphnia magna STRAUS, parthenogenetic females; Strain of Bundesgesundheitsamt Berlin (Germany)
The culture water (so-called 'M4 medium') is partly renewed once a week.

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Hardness:

13.8° dh (= 246.3 mg/L CaCO3)

Test temperature:

19.7°C

pH:

7.9

Dissolved oxygen:

8.7 - 8.9 mg/L (saturation 95 -96%)

Nominal and measured concentrations:

Nominal concentration: 3.2, 6.3, 12.5, 25, 50 and 100 mg/L

Duration:

48 h

Dose descriptor:

EC0

Effect conc.:

11.35 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

26.6 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: Probit analysis

Duration:

48 h

Dose descriptor:

EC100

Effect conc.:

92.35 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

The results are expressed in terms of nominal concentrations (at 24 h), and in terms of mean measured concentrations (at 48 h). Measured concentrations ranged from 93.1 - 104% of nominal values at 0 hours, and from 81.3 - 91.6% of nominal values at 48 hours, respectively.
The EC 50 was calculated by probit analysis.

Results:

Nominal concentration mg/L	Measured concentration at 0 h mg/L	Measured concentration at 48 h mg/L
control	< 0.5	< 0.5
3.2	3.1	2.6
6.3	6.3	5.5
12.5	11.8	10.9
25	26.0	22.9
50	50.1	42.2
100	93.1	91.6*

* The figure marked by asterisk has already been measured after 24 hours of exposure because of early 100% immobilisation rates of the daphnids.

Validity criteria fulfilled:

yes

Remarks:

The immobilisation and other abnormalities in the controls did not exceed 10% by the end of the test.• The dissolved oxygen concentration remained above 8 mg/L throughout the exposure period.

Conclusions:

The acute toxicity of L-Menthol (CAS no. 2216-51-5) to invertebrates (Daphnia magna) was determined in a static immobilisation study according to to EU Method C.2 (Acute Toxicity for Daphnia). After 48 hours of exposure an EC50 of 26.6 mg/L (measured) is obtained.

Executive summary:

The study was performed to assess the acute toxicity of L-Menthol (CAS 2216 -51 -5) to Daphnia magna Straus under static conditions in a closed bottle system. The study was conducted in accordance with the Method C.2 ‘Acute toxicity for Daphnia’ which is equivalent to OECD Guideline for Testing of Chemicals No. 202 'Daphnia sp., Acute Immobilisation Test'. The Daphnia were exposed to a range of concentrations, nominally 3.2, 6.3, 12.5, 25, 50 and 100 mg/L of L-Menthol dissolved in dilution water. 20 animals were tested per concentration. Observations were made on the swimming ability and the immobilisation rate respectively. After 24 hours of exposure an EC50 of 37.7 mg/L and after 48 hours of exposure an EC50 of 26.6 mg/L is obtained.

Reference 2

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Justification for type of information:

See 'Attached justification' document: Justification for a read-across approach from L-Menthol (CAS No 2216-51-5, EC No 218-690-9) [Source] to D/L-Menthol (CAS No 89-78-1, EC No 201-939-0) [Target].

Reason / purpose for cross-reference:

read-across source

Duration:

48 h

Dose descriptor:

EC0

Effect conc.:

11.35 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

26.6 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: Probit analysis

Duration:

48 h

Dose descriptor:

EC100

Effect conc.:

92.35 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

The results are expressed in terms of nominal concentrations (at 24 h), and in terms of mean measured concentrations (at 48 h). Measured concentrations ranged from 93.1 - 104% of nominal values at 0 hours, and from 81.3 - 91.6% of nominal values at 48 hours, respectively.
The EC 50 was calculated by probit analysis.

Results:

Nominal concentration mg/L	Measured concentration at 0 h mg/L	Measured concentration at 48 h mg/L
control	< 0.5	< 0.5
3.2	3.1	2.6
6.3	6.3	5.5
12.5	11.8	10.9
25	26.0	22.9
50	50.1	42.2
100	93.1	91.6*

* The figure marked by asterisk has already been measured after 24 hours of exposure because of early 100% immobilisation rates of the daphnids.

Validity criteria fulfilled:

yes

Remarks:

The immobilisation and other abnormalities in the controls did not exceed 10% by the end of the test.• The dissolved oxygen concentration remained above 8 mg/L throughout the exposure period.

Conclusions:

The acute toxicity of L-Menthol (CAS no. 2216-51-5) to invertebrates (Daphnia magna) was determined in a static immobilisation study according to to EU Method C.2 (Acute Toxicity for Daphnia). After 48 hours of exposure an EC50 of 26.6 mg/L (measured) is obtained.

Executive summary:

The acute toxicity of L-Menthol (CAS no. 2216-51-5) to invertebrates (Daphnia magna) was determined in a static immobilisation study according to EU Method C.2 (Acute Toxicity for Daphnia) which is similar to the OECD Guideline 202. After 48 hours of exposure an EC50 of 26.6 mg/L (measured) is obtained.

Comparing the details on physico-chemical properties for DL-Menthol (CAS no. 89 -78 -1) in the endpoint entries and L-Menthol (2216-51-5) highlights that the Menthols can be considered as a category, as was concluded by the OECD SIDS report (2003). There are no functional groups that are different between the source and target chemical which could affect the anticipated toxicity.

In the OECD SIDS report (2003) the endpoint “short-term toxicity to aquatic invertebrates” of Menthol is given with an effect range for Daphnia magna of: 24 h EC50 = 37.7 - 71 mg/L and 48 h EC50 = 26.6 mg/L for all Menthols that are given above. The study providing the latter effect concentration was investigated on L-Menthol (CAS no. 2216-51-5) and selected for read-across to DL-Menthol (CAS no. 89 -78 -1).

Description of key information

Read-across:

A study was performed to assess the acute toxicity of L-Menthol (CAS 2216 -51 -5) to Daphnia magna Straus under static conditions in a closed bottle system. The study was conducted in accordance with the Method C.2 ‘Acute toxicity for Daphnia’ which is equivalent to OECD Guideline for Testing of Chemicals No. 202 'Daphnia sp., Acute Immobilisation Test'. The Daphnia were exposed to a range of concentrations. After 24 hours of exposure an EC50 of 37.7 mg/L and after 48 hours of exposure an EC50 of 26.6 mg/L is obtained.

Comparing the details on physico-chemical properties for DL-Menthol (CAS no. 89 -78 -1) in the endpoint entries and L-Menthol (2216-51-5) highlights that the Menthols can be considered as a category, as was concluded by the OECD SIDS report (2003). There are no functional groups that are different between the source and target chemical which could affect the anticipated toxicity.

In the OECD SIDS report (2003) the endpoint “short-term toxicity to aquatic invertebrates” of Menthol is given with an effect range for Daphnia magna of: 24 h EC50 = 37.7 - 71 mg/L and 48 h EC50 = 26.6 mg/L for all Menthols that are given above. The study providing the latter effect concentration was investigated on L-Menthol (CAS no. 2216-51-5) and selected for read-across to DL-Menthol (CAS no. 89 -78 -1).

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

26.6 mg/L

Additional information

Another study has been performed by Bayer (1990) according to "Bestimmung der Schwimmfähigkeit beim Wasserfloh -Daphnia magna-; Verfahrensvorschlag: Umweltbundesamt Berlin, Stand: Mai 1984". The testing was done with five concentrations (250.0, 125.0, 63.0, 31.0, 15.7, 7.8, 4.0, 2.0 mg/L (nominal)). 10 daphnids/vessel and 2 replicates were done for each concentration. An EC0 = 15.7 mg/L and an EC100 = 125 mg/L could be determined. However, the duration of the study only took 24 h, which is too short for the assessment in the environment as the duration should be 48 h at least.