Fenitrothion

Short-term toxicity to aquatic invertebrates

Administrative data

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

4 March 1987 - 6 March 1987

Reliability:

1 (reliable without restriction)

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1987

Report date:

1987

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

EPA OPP 72-2 (Aquatic Invertebrate Acute Toxicity Test)

Version / remarks:

U.S. EPA FIFRA, 40 CFR, Part 158.145 Guideline72-2 (1982)

Deviations:

no

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Fenitrothion

EC Number:

204-524-2

EC Name:

Fenitrothion

Cas Number:

122-14-5

Molecular formula:

C9H12NO5PS

IUPAC Name:

O,O-dimethyl O-3-methyl-4-nitrophenyl phosphorothioate

Test material form:

liquid

Specific details on test material used for the study:

Batch No.: 60553, Purity: 94.5%,

Sampling and analysis

Analytical monitoring:

yes

Details on sampling:

Measured values for each concentration of the test solutions were determined at the beginning and at the end of the study.

Test solutions

Vehicle:

yes

Test organisms

Test organisms (species):

Daphnia magna

Details on test organisms:

Age of organisms at study initiation: first-instar (less than 24 hours old)

Study design

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Test conditions

Nominal and measured concentrations:

Nominal: 0.0024, 0.0048, 0.0095, 0.019, 0.038, 0.075, 0.150 and 0.300 mg/l
Measured: 0, 0.002, 0.0043, 0.010, 0.020, 0.040, 0.084, 0.180, and 0.340 mg/l

Results and discussion

Effect concentrations

Effect concentrations 1

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

0.009 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

mortality

Effect concentrations 2

Key result

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

0.002 < mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

mortality

Details on results:

The measured concentrations of Fenitrothion yielded an average of 104 + 12% of the nominal concentrations for this 48-hours study.

Any other information on results incl. tables

Mortality* and behavioural observations

 

Mean measured concentrations (Nominal concentrations) (mg/l)	number of daphnids	24 hr		48 hr
		Mortality*	Observations	Mortality*	Observations
Control	20	0	20N	0	20N
Solvent control	20	0	20N	0	20N
0.0020  (0.0024)	20	0	20N	1	3N 16ERR
0.0043  (0.0048)	20	0	20ERR	1	4ERR 8OB/ERR 7OB/Q
0.010    (0.0095)	20	0	13OB/Q 5OB/ERR 2ERR	10	10OB/Q
0.020    (0.019)	20	3	13OB/Q 4OB/ERR	20	---
0.040    (0.038)	20	0	20OB/Q	20	---
0.084    (0.075)	20	1	13OB/Q 6OB/Q/C	20	---
0.180    (0.150)	20	6	14OB/Q/C	20	---
0.340    (0.300)	20	11	9OB/Q/C	20	---

N= Normal; ERR= Erratic Movement; C= Clumping of Daphnia; OB= On Bottom; Q= Quiescent

*: Since in this study the mortality was confirmed by checking for daphnid movement in response to gentle prodding with a glass pipe,

this “mortality” is equivalent to “immobilisation” which is defined in Directive 92/69/EEC Method C2.

Therefore the EC₅₀value is estimated based on this mortality, namely immobilisation data.

 

Applicant's summary and conclusion

Validity criteria fulfilled:

not specified

Conclusions:

Conclusion: 48hr-EC50: 0.0086mg/l, 48hr-NOEC: < 0.002mg/l

Executive summary:

The acute toxicity study of Penitrothion to Daphnia magna was assessed. Water quality parameters of temperature, dissolved oxygen and pH were measured at the termination of the test and were within acceptable limits. Analytical samples were taken at 0 and 48 hours of testing. 48hr EC50: 0.0086 mg/L, 48 hr NOEC: <0.002mg/L