Nitrogen monoxide

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

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Data source

Reference

Reference Type:

publication

Title:

Interacting effects of pH acclimation, pH, and heavy metals on acute and chronic toxicity to Ceriodaphnia dubia (Cladocera)

Author:

Belanger SE and Cherry DS

Year:

1990

Bibliographic source:

Journal of Crustacean Biology, 10(2): 225-235.

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Principles of method if other than guideline:

Daphnids reared in pH 8.0

GLP compliance:

not specified

Test material

Test material information

Constituent 1

Reference substance name:

Nitric acid

EC Number:

231-714-2

EC Name:

Nitric acid

Cas Number:

7697-37-2

Molecular formula:

HNO3

IUPAC Name:

nitric acid

Specific details on test material used for the study:

HNO3 is degradation product of NO in water so this study expresses the aquatic toxicity of NO.

Sampling and analysis

Analytical monitoring:

not specified

Remarks:

indirect: pH measurement

Test solutions

Vehicle:

yes

Remarks:

test material Nitric acid was supplied as a 1% solution (in water presumably)

Test organisms

Test organisms (species):

Ceriodaphnia dubia

Details on test organisms:

Ceriodaphnia dubia were obtained from US EPA Duluth stock in 1984 from T.J. Norberg and were cultured in water from New River (Virginia).

Study design

Test type:

not specified

Water media type:

freshwater

Total exposure duration:

48 h

Test conditions

Hardness:

98 mg/L

Test temperature:

25°C

pH:

Two tests were conducted at nominal pH values of 3.0, 4.0, 5.0, 6.0, 7.0, 8.0, 9.0, 10.0, 11.0, and 12.0 to determine the pH LC50. pH was adjusted using HNO3

Nominal and measured concentrations:

see pH

Results and discussion

Effect concentrations

Key result

Duration:

48 h

Dose descriptor:

LC50

Effect conc.:

4.6 other: pH

Nominal / measured:

meas. (not specified)

Conc. based on:

other: pH

Basis for effect:

mortality

Details on results:

Ceriodaphnia dubia cultured at pH 8.0 suffered 100% mortality at pH 3.2-3.4. The individual 48-h LC50s for acidic pH were 4.4 and 4.7. Grand probits (analyses combined) were 4.6 for acid pH.

Applicant's summary and conclusion

Conclusions:

Ceriodaphnia dubia cultured at pH 8.0 suffered 100% mortality at pH 3.2-3.4. The 48-h LC50 was pH=4.6.
HNO3 is degradation product of NO in water so this result expresses the aquatic toxicity of NO.