2,4-dinitroanisole

Toxicity to aquatic algae and cyanobacteria

Link to relevant study record(s)

Reference

Endpoint:

toxicity to aquatic algae and cyanobacteria

Type of information:

experimental study

Adequacy of study:

key study

Study period:

June 2011

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

comparable to guideline study with acceptable restrictions

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 201 (Freshwater Alga and Cyanobacteria, Growth Inhibition Test)

GLP compliance:

not specified

Remarks:

Study conducted to a high scientific standard and findings presented in a comprehensive test report.

Specific details on test material used for the study:

Not specified

Analytical monitoring:

yes

Details on sampling:

- Concentrations: 10 serial dilutions
- Sample storage conditions before analysis: Fresh stock solutions of EMs were prepared by adding EMs to water and stirred up to 10 d. Then, each stock solution was filtered using syringes and 0.45 μm filter units. For DNAN samples, aliquots were mixed (1:1) with acetonitrile, and diluted if needed using a mixture of acetonitrile water (1:1).

Vehicle:

yes

Remarks:

acetonitrile

Details on test solutions:

none

Test organisms (species):

Raphidocelis subcapitata (previous names: Pseudokirchneriella subcapitata, Selenastrum capricornutum)

Details on test organisms:

none

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

96 h

Post exposure observation period:

none

Hardness:

not specified

pH:

4.96 - 3.67

Dissolved oxygen:

not specified

Salinity:

not specified

Conductivity:

not specified

Nominal and measured concentrations:

not specified

Details on test conditions:

TEST SYSTEM
- Test vessel: 96-well microplate
- Material, size, headspace, fill volume: 200 µL
- No. of vessels per concentration (replicates): 3
- No. of vessels per control (replicates): 3

OTHER TEST CONDITIONS
- Sterile test conditions: not specified
- Adjustment of pH: yes
- Photoperiod: 24h
- Light intensity and quality: 5000 lux

Reference substance (positive control):

yes

Remarks:

zinc sulfate

Key result

Duration:

96 h

Dose descriptor:

LOEC

Effect conc.:

2.3 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Key result

Duration:

96 h

Dose descriptor:

NOEC

Effect conc.:

1.2 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Key result

Duration:

96 h

Dose descriptor:

EC50

Effect conc.:

2.2 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Key result

Duration:

96 h

Dose descriptor:

EC20

Effect conc.:

1.4 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Details on results:

none

Results with reference substance (positive control):

none

Reported statistics and error estimates:

none

none

Validity criteria fulfilled:

not specified

Conclusions:

Individual exposure of DNAN inhibited P. subcapitata growth in the 96-h exposure test. It was found that the LOEC, NOEC nad EC50 were 2.3 mg/L, 1.2 mg/L and 2.2 mg/L, respectively.

Executive summary:

The present report summarizes findings on the environmental fate and ecological impact of DNAN. Firstly, aqueous solubility (S_w), octanol/water partition coefficients (K_ow), sorption and stability of the chemical in two soils (DRDC-08 and DRDC-09 as provided by DRDC) were measured. Secondly, the toxicity of DNAN on various ecological receptors including earthworms, alga, and bacteria were determined. Preliminary findings indicated that DNAN has a higher sorption coefficient indicating that this chemical will stay close to the soil surface. However the test item was found to photodegrade at wavelengths within the range of solar irradiation. Also indigenous bacteria in soil were found capable of degrading DNAN. These preliminary experimental findings indicate that DNAN may not stay in the open environment indefinitely but rather they can photodegrade (soil surface) and biodegrade. For the ecotoxicological evaluation, preliminary experiments were done using DNAN dissolved in water. Acute toxicity tests using Vibrio fisheri(Microtox), Pseudokirchneriella subcapitata, and Eisenia andreiwere done. In addition, SOS chromotest was performed to evaluate genotoxic effects of the test chemicals. Preliminary results indicated that DNAN is toxic to the three test species, and was genotoxic to bacteria.

Description of key information

96-h exposure test found that NOEC and EC50 of DNAN were 1.2 mg/L and 2.2 mg/L, respectively.

Key value for chemical safety assessment

EC50 for freshwater algae:

2.2 mg/L

EC10 or NOEC for freshwater algae:

1.2 mg/L