2-nitro-4-(trifluoromethyl)benzonitrile

Toxicity to soil macroorganisms except arthropods

Administrative data

Endpoint:

toxicity to soil macroorganisms except arthropods: short-term

Type of information:

experimental study

Adequacy of study:

key study

Study period:

17 Oct – 07 Dec 2019

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2020

Report date:

2020

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 207 (Earthworm, Acute Toxicity Tests)

Version / remarks:

1984

GLP compliance:

yes

Remarks:

The test was performed in compliance with the requirements of the Principles of Good Laboratory Practices (GB/T 22278-2008).

Test material

Test material information

Constituent 1

Reference substance name:

2-nitro-4-(trifluoromethyl)benzonitrile

EC Number:

212-298-1

EC Name:

2-nitro-4-(trifluoromethyl)benzonitrile

Cas Number:

778-94-9

Molecular formula:

C8H3F3N2O2

IUPAC Name:

2-nitro-4-(trifluoromethyl)benzonitrile

Sampling and analysis

Analytical monitoring:

no

Test substrate

Vehicle:

no

Details on preparation and application of test substrate:

- Method of mixing into soil (if used): First, a fixed quantity of the test substance was mixed with quartz sand, in total 10 g, this was then added to the test vessel, and mixed thoroughly with 550 g artificial soil (dry soil), finally ultra-pure water was used to adjust soil moisture content to approximately 35% (soil dry weight).

Test organisms

Test organisms (species):

Eisenia fetida

Animal group:

annelids

Details on test organisms:

TEST ORGANISM
- Common name: Earthworm (Eisenia foetida)
- Source: Wangjun Earthworm Farm, Zhutangtou, Huayang Street, Jurong
- Weight at test initiation (mean and range, SD): 355 - 478 mg

ACCLIMATION
- Acclimation period: Newly purchased earthworms were quarantined and isolated for 14 days.
- Acclimation conditions (same as test or not): Before the test started, the test earthworms were cultivated for 24 h in the test soil environment.
- Other: Prior to use, they were rinsed clean with ultra-pure water and surface moisture was wiped dry with filter paper.

Study design

Study type:

laboratory study

Substrate type:

artificial soil

Limit test:

yes

Total exposure duration:

14 d

Test conditions

Test temperature:

During the test: 19.3 - 20.1 °C

pH:

During the test: 5.99 - 6.11

Moisture:

During the test: 25% - 36% of the soil’s dry weight

Details on test conditions:

TEST SYSTEM
- Test container (material, size): Specimen bottle (1 L, Φ12 cm, Yancheng Glass Instrument Factory No. 2); Ecological culture box (JM-600, Jiangsu Jiamei Instrument Manufacturing Co., Ltd., temperature change controlled to ± 2 °C, light intensity was 400 Lux - 800 Lux)
- Amount of soil or substrate: 10 g quartz sand, 550 g artificial soil (dry soil)
- No. of organisms per container (treatment): 10
- No. of replicates per treatment group: 4
- No. of replicates per control: 4

SOURCE AND PROPERTIES OF SUBSTRATE (if soil)
- Composition (if artificial substrate): Peat (Sphagnum palustre) 10% (Denmark Pindstrup (Group) Co., pH value 5.5 - 6.5, no obvious plant residue, finely ground, air dried); Kaolin clay 20% (CAS: 1332-58-7, batch no.: 20190827, Shanghai Best More Industry Co., Ltd., kaolinite content 30 %); Quartz sand 70% (CAS: 14808-60-7, Shanghai Aibi Chemical Reagent Co., Ltd., 50-200 μm granularity fine sand 80% content).
- Pretreatment of soil: Ultra-pure water was used to adjust soil moisture content to approximately 35% (soil dry weight).

OTHER TEST CONDITIONS
- Photoperiod: continuous light
- Light intensity: 572 Lux - 748 Lux

EFFECT PARAMETERS MEASURED (with observation intervals if applicable):
- Mortality: At day 7 of exposure, the test medium inside the culture bottle was gently poured out onto a stainless-steel plate, the earthworms taken out, the front end of the earthworm tested for response to mechanical stimulus, and symptoms and number of deaths were recorded. If the front end of the earthworm had no obvious response to gentle mechanical stimulus, then it was determined to be dead. After the inspection ended, the test medium was again placed in the culture bottle and surviving earthworms were placed on the surface of the test medium to continue culturing. At day 14, the same test was performed again.
- Body weight: On day 0 and 14 of the test, mean earthworm body weight in the blank control group and the test groups was measured
- Other: On day 7 and day 14, at the same time that mortality rate was examined, pathological symptoms and abnormal behaviour were observed in the earthworms (e.g. weakness and rigidity).

TEST CONCENTRATIONS
- Range finding study: yes
- Test concentrations: 0 (Control) and 1000 mg/kg soil dw

Reference substance (positive control):

yes

Remarks:

2-chloroacetamide

Results and discussion

Effect concentrations

Effect concentrations 1

Duration:

14 d

Dose descriptor:

NOEC

Effect conc.:

>= 1 000 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality

Effect concentrations 2

Duration:

14 d

Dose descriptor:

LC50

Effect conc.:

> 1 000 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality

Details on results:

- Mortality at end of exposure period: At day 14, there were no earthworm deaths in the 1000 mg/kg (soil dry weight) concentration group. No deaths occurred in the control group during the pre-test and the limit test.
- Other biological observations: At the start of the test, after the earthworms came into contact with the chemical in the soil they quickly burrowed into the soil and were active in the soil throughout the entire test.
- Other: No unusual environmental changes that might affect the integrity and quality of the test were observed.

Results with reference substance (positive control):

- Other: Measurement of 7d-LC50 and 14d-LC50 for the reference compound (2-chloroacetamide) was carried out once every six months to confirm that the test conditions satisfied the test requirements and no significant changes had occurred. The results show that the 7d-LC50 of the reference compound is 49.2 mg/kg and the 14d-LC50 is 32.5 mg/kg.

Any other information on results incl. tables

Table 1: Measurement Results for NTBN Acute Toxicity in Earthworms (Limit Test)

Treatment dose (mg/kg (soil dry weight))	Earthworm count (n)	Death count (n)
		7 d	14 d
0	10	0	0
0	10	0	0
0	10	0	0
0	10	0	0
1000	10	0	0
1000	10	0	0
1000	10	0	0
1000	10	0	0
LC50 (mg/kg (soil dry weight))		>1000	>1000

 

  

Table 2: Mean Earthworm Body Weight at Start and End of Exposure Period

Treatment dose (mg/kg (soil dry weight))	Mean body weight at d 0 (mg)	Mean body weight at d 14 (mg)
0	417	394
0	478	431
0	443	399
0	355	335
1000	376	331
1000	465	415
1000	401	357
1000	436	396
Minimum value	355	331
Maximum value	478	431

 

Table 3: Validity criteria for OECD 207 (1984)

Criterion	Outcome	Criterion fulfilled
Mortality in the control ≤10 % at the end of the test.	No deaths (0) occurred in the control group during the pre-test and the limit test.	yes

 

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Remarks:

See Table 3 in "Any other information on results incl. tables".