Octyl (R)-2-(4-chloro-2-methylphenoxy)propionate

Long-term toxicity to fish

Administrative data

Endpoint:

long-term toxicity to fish

Type of information:

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

Adequacy of study:

other information

Study period:

1993

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Reliable source.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1993

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 204 (Fish, Prolonged Toxicity Test: 14-day Study)

Version / remarks:

prolonged to 28 days

Deviations:

not specified

GLP compliance:

not specified

Test material

Test material information

Constituent 1

Reference substance name:

(R)-2-(4-chloro-2-methylphenoxy)propionic acid

EC Number:

240-539-0

EC Name:

(R)-2-(4-chloro-2-methylphenoxy)propionic acid

Cas Number:

16484-77-8

Molecular formula:

C10H11ClO3

IUPAC Name:

(2R)-2-(4-chloro-2-methylphenoxy)propanoic acid

Constituent 2

Reference substance name:

Mecoprop-P acid

IUPAC Name:

Mecoprop-P acid

Constituent 3

Reference substance name:

MCPP-P acid

IUPAC Name:

MCPP-P acid

Details on test material:

Purity: 92.7 %

Sampling and analysis

Analytical monitoring:

yes

Test organisms

Test organisms (species):

Oncorhynchus mykiss (previous name: Salmo gairdneri)

Details on test organisms:

Oncorhynchus mykiss Walbaum 1792
mean length: 6 cm
mean weight: 1.9 g

Study design

Test type:

flow-through

Water media type:

freshwater

Limit test:

no

Total exposure duration:

28 d

Test conditions

Test temperature:

16°C

pH:

8.4

Nominal and measured concentrations:

Nominal: 0, 1, 10, 50 and100 mg/L
The measured concentrations averaged 96 % of the range 88.8 - 105.1 %

Results and discussion

Effect concentrations

Duration:

28 d

Dose descriptor:

NOEC

Effect conc.:

50 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality

Any other information on results incl. tables

No mortality occured in any test group. Signs or symtoms of toxicity were only observed at the highest concentration of 100 mg/L where slight discoloration was observed on day 2 and 5 of the study. Compared with the control group at the end of the study, the mean body weight at 100 mg/L was statistically significant smaller (<=0.05) and the mean body length at 100 mg/L was statistically significant smaller (<=0.01).

Applicant's summary and conclusion

Validity criteria fulfilled:

not specified

Remarks:

expected to be valid source

Conclusions:

For Mecoprop-P acid (MCPP-P acid), the hydrolysis product of Mecoprop-P n-octyl ester, a 28 d-NOEC of 50 mg/L was determined.

Executive summary:

Mecoprop-P n-octyl ester hydrolyses rapidly in natural water. Therefore, the hydrolysis product Mecoprop-P acid (MCPP-P acid) was used for further assessment of Mecoprop-P n-octyl ester with respect to toxicity to fish.

 

In a prolonged toxicity test with Mecoprop-P acid (MCPP-P acid) in a flow-through system according to the OECD Guideline 204 a 28 d-NOEC of 50 mg/l was obseved on Oncorhynchus mykiss.