Bis(methylcyclohexyl) phthalate

Long-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

long-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Remarks:

vehicle was used

Qualifier:

according to guideline

Guideline:

OECD Guideline 211 (Daphnia magna Reproduction 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: GG01
- Purity: 99.9% (GC method)

Analytical monitoring:

yes

Vehicle:

yes

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
- Method: A respective amount of test substance and vehicle was added to synthetic freshwater in order to a treatment concentration of 2 mg/L and a vehicle concentration of 100 mg/L.
- Chemical name of vehicle (organic solvent, emulsifier or dispersant): Dimethylformamid, HCO-60
- Concentration of vehicle in test medium (stock solution and final test solution(s) or suspension(s) including control(s)): 100 mg/L

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: water flea
- Source: National Institute for Environmental Studies
- Age of parental stock (mean and range, SD): < 24h
- Feeding during test
- Food type: Chlorella vulgaris
- Amount: Ration: 0.2 mg C (organic carbon content) /Daphnia magna / day

ACCLIMATION
- Acclimation period: Jan19th,2000–Feb7th,2000
- Acclimation conditions (same as test or not): same
- Food type: Chlorella vulgaris
- Amount: Ration: 0.2 mg C (organic carbon content) /Daphnia magna / day
- Health during acclimation (any mortality observed): The death rate of parents: 2 weeks before exposure was below 5% and no occurrence of resting egg and male were recognized.

Test type:

semi-static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

21 d

Hardness:

-

Test temperature:

20 ± 1 °C

pH:

not specified

Dissolved oxygen:

not specified

Nominal and measured concentrations:

Nominal: 0.02, 0.063, 0.2, 0.63 and 2 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: Vessel with 80 mL test solution
- Type (delete if not applicable): covered water surface with teflon sheet
- Renewal rate of test solution (frequency/flow rate): renewal total amount of test solution every 24 hours
- No. of organisms per vessel: 10
- No. of vessels per concentration (replicates): 1
- No. of vessels per control (replicates): 1
- No. of vessels per vehicle control (replicates): 1

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: synthetic freshwater
- Intervals of water quality measurement: The pH was measured at the beginning of test and around the timing of water exchange every 24 hours.

OTHER TEST CONDITIONS
- Photoperiod: 16h light/ 8h dark
- Light intensity: room light

EFFECT PARAMETERS MEASURED: Reproductive output was recorded after 21d exposure time.

Reference substance (positive control):

not specified

Key result

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

0.181 mg/L

Nominal / measured:

meas. (TWA)

Conc. based on:

test mat.

Basis for effect:

reproduction

Duration:

21 d

Dose descriptor:

EC50

Effect conc.:

0.679 mg/L

Nominal / measured:

meas. (TWA)

Conc. based on:

test mat.

Basis for effect:

mortality

Validity criteria fulfilled:

yes

Conclusions:

The test substance is harmful to aquatic invertebrates at chronic exposure.

Executive summary:

One long-term toxicity test was performed to assess the chronic toxicity of dicyclohexyl phthalate to the aquatic invertebrate Daphnia magna. The study was conducted under GLP and according to OECD guideline 211. The study was performed in a closed semi-static system. Daphnids were exposed to the test substance at test concentrations between 0.02 and 2 mg/L using a vehicle to fascilitate exposure. Measurement values (time-weighted average values) were adopted for calculation of effect concentration, because some measurement concentrations of test substance exceeded ±20 % of nominal values. The 21d-NOEC value is determined to be 0.181 mg/L based on measured concentrations.

Reference 2

Endpoint:

long-term toxicity to aquatic invertebrates

Type of information:

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

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Remarks:

vehicle was used

Justification for type of information:

REPORTING FORMAT FOR THE ANALOGUE APPROACH
The analogue justification document is attached to chapter 13.

Reason / purpose for cross-reference:

read-across source

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source and lot/batch No.of test material: GG01
- Purity: 99.9% (GC method)

Key result

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

0.181 mg/L

Nominal / measured:

meas. (TWA)

Conc. based on:

test mat.

Basis for effect:

reproduction

Duration:

21 d

Dose descriptor:

EC50

Effect conc.:

0.679 mg/L

Nominal / measured:

meas. (TWA)

Conc. based on:

test mat.

Basis for effect:

mortality

Conclusions:

The test substance is harmful to aquatic invertebrates at chronic exposure.

Description of key information

NOEC (21d) = 0.181 mg/L (measured, vehicle) for reproductive output of Daphnia magna (OECD 211, read across)

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

0.181 mg/L

Additional information

Since no studies assessing the long-term toxicity of Bis(methylcyclohexyl) phthalate (CAS 27987-25-3) to aquatic invertebrates is available, in accordance to Regulation (EC) No. 1907/2006 Annex XI, 1.5 Grouping of substances, a read-across to the structurally related source substance Dicyclohexyl phthalate (CAS 84-61-7) was conducted. The analogue justification document is attached to chapter 13.

The study with the read across substance was performed by the Japanese environmental agency under GLP according to OECD guideline 211 using Daphnia magna as test organism (MOE 2000). Dimethylformamid and HCO-60 were used to fascilitate the solubility of the substance in the test solution. test concentrations between 0.02 and 2 mg/L were tested. Measured values (TWA) were adopted for calculation of effect concentrations, because some measurement concentrations of the test substance exceeded +-20% of nominal values. The 21d-NOEC value is determined to be 0.181 mg/L. Thus, the substance is harmful to aquatic invertebrates at chronic exposure. Based on the high structural similarity which leads to similar environmental behaviour and ecotoxicity this conclusion can also considered true for the target substance Bis(methylcyclohexyl) phthalate.