4-mesyl-2-nitrotoluene

Toxicity to soil macroorganisms except arthropods

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

toxicity to soil macroorganisms except arthropods: short-term

Type of information:

experimental study

Adequacy of study:

key study

Study period:

03 Aug 2005 to 29 Sep 2005

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP compliant, guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 207 (Earthworm, Acute Toxicity Tests)

Deviations:

no

GLP compliance:

yes

Analytical monitoring:

no

Vehicle:

no

Details on preparation and application of test substrate:

- Method of mixing into soil (if used): Test solutions were made up as quartz sand stock. This was thoroughly mixed with with the soil substrate using a spatula.
- Controls: 4 untreated replicates.

Test organisms (species):

Eisenia fetida

Animal group:

annelids

Details on test organisms:

TEST ORGANISM
- Common name: Earthworm
- Source: Blade Biological Ltd., Cowden, Edenbridge, Kent, TN8 7DX.
- Age at test initiation (mean and range, SD): approximately 2 months with clitellum
- Weight at test initiation (mean and range, SD): 0.353 - 0.467 mg/worm (mean mass of worms in replicates)


ACCLIMATION
- Acclimation period: Not reported
- Acclimation conditions (same as test or not): Same as test
- Health during acclimation (any mortality observed): Not reported

Study type:

laboratory study

Substrate type:

artificial soil

Limit test:

no

Total exposure duration:

14 d

Test temperature:

18.9-21.8°C

pH:

Control: 6.29
Test substance groups: 6.18 - 6.35
Reference substance groups: 6.22 - 6.71
Measured at test end.

Moisture:

Control: 33.2 % at test start, 31.2 % at test end
Test substance groups: 31.9 - 33.4 % at test start, 30.9 - 33.1 % at test end
Reference substance groups: 29.9 - 33.3 % at test start, 29.5 - 31.2 % at test end (for replicates not discarded due to total mortality)

Details on test conditions:

TEST SYSTEM
- Test container (material, size): 1 L glass flat-bottomed beakers covered with glass Petri dish.
- Amount of soil or substrate: Approximately 750 g wet weight
- 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)
- Collection procedures: Not applicable - soil is artificial
- Composition (if artificial substrate): 10% sphagnum peat, 20% kaolinite clay, 0.35% calcium carbonate, 69.65% industrial quartz sand (more than 50% of the particles between 0.05 mm and 0.2 mm), deionised water.
- Organic carbon (%): Not reported
- Maximum water holding capacity (in % dry weight): Not reported
- Pretreatment of soil: Deionised water added to bring to deisired level. pH was adjusted.

OTHER TEST CONDITIONS
- Photoperiod: Continuous
- Light intensity: 415 - 676 lux

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :
At test start: Fresh weight per worm
At 7 days: Number of surviving worms per replicate, morphological alterations when apparant
At 14 days: Number of surviving worms per replicate, morphological alterations when apparant, fresh weight per worm

VEHICLE CONTROL PERFORMED: Not applicable

TEST CONCENTRATIONS
- Spacing factor for test concentrations: 2
- Test concentrations: nominal 0 (control), 62.5, 125, 250, 500, 1000 mg/kg soil d.w.

Nominal and measured concentrations:

nominal: 0 (control), 62.5, 125, 250, 500, 1000

Reference substance (positive control):

yes

Remarks:

2-chloroacetamide

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

Duration:

14 d

Dose descriptor:

NOEC

Effect conc.:

250 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: biomass

Details on results:

- Mortality at end of exposure period: Control: 7.5% 62.5 mg/kg: 2.5% 125 mg/kg: 0% 250 mg/kg: 0% 500 mg/kg: 0% 1000 mg/kg: 25%
- Mean (±SD) mass of adults at beginning of test: Control: 0.393 ± 0.006 g 62.5 mg/kg: 0.395 ± 0.031 g 125 mg/kg: 0.413 ± 0.024 g 250 mg/kg: 0.413 ± 0.013 g 500 mg/kg: 0.399 ± 0.003 g 1000 mg/kg: 0.437 ± 0.022 g
- Changes in body weight of live adults (% of initial weight) at end of exposure period: Control: -11.6% 62.5 mg/kg: -13.1% 125 mg/kg: -15.0% 250 mg/kg: -16.5% 500 mg/kg: -22.5% 1000 mg/kg: -29.0%
- No. of offspring produced: Not reported
- No. of unhatched cocoons: Not applicable
- Morphological abnormalities: None observed
- Behavioural abnormalities: None observed

Results with reference substance (positive control):

- Results with reference substance valid? Yes
- Relevant effect levels: LC50: 19.18 mg/kg soil d.w.

Reported statistics and error estimates:

The LC50 was calculated using the Quantal Dose Response model in StEvE version 1.1.
The NOEC was obtained by performing analysis of variance and then comparing with the control using two-tailed Dunnett's test (Hsu 1996) with 5% type one error rate.

Table 1: Effects of the substance on Eisenia fetida biomass after 14 days exposure

Treatment group	mg/kg soil d.w.
	control	62.5	125	250	500	1000
	Initial fresh weight / worm [mg] (mean per replicate)
mean	0.393	0.395	0.413	0.413	0.399	0.437
SD	0.006	0.031	0.024	0.013	0.003	0.022
cv %	1.6	7.8	5.9	3.1	0.8	5
	Fresh weight / worm [mg] after 14 days (mean per replicate)
mean	0.347	0.344	0.352	0.345	0.309	0.31
SD	0.025	0.045	0.029	0.035	0.009	0.029
cv %	7.1	13.1	8.2	10.1	3	9.4
	Biomass change (change in fresh weight after 14 days relative to initial fresh weight) weight / worm [mg] (mean per replicate)
mean	-0.046	-0.051	-0.062	-0.068	-0.09	-0.126
SD	0.023	0.02	0.017	0.029	0.01	0.015
cv %	-51.4	-38.4	-27.3	-42.9	-11.6	-12.2
	Biomass change (change in fresh weight after 14 days relative to initial fresh weight) [%] (mean per replicate)
mean	-11.6	-13.1	-15	-16.5	-22.5	-29

Table 2: Effects of the substance on mortality of Eisenia fetida

Endpoint	Treatment group
	(mg/kg soil d.w.)
	Control	62.5	125	250	500	1000
Mortality of adult worms after 7 days (%)	7.5	0	0	0	0	10
Mortality of adult worms after 14 days (%)	7.5	2.5	0	0	0	25
LC50	> 1000 mg/kg soil d.w.

 

Validity criteria fulfilled:

yes

Remarks:

control adult mortality <10 % (7.5% after 14 days)

Conclusions:

Based on nominal concentration, the 14-day LC50 for earthworms (Eisenia fetida) was >1000 mg/kg soil d.w. and the 14-day NOEC (biomass) was 250 mg/kg soil d.w.

Executive summary:

In an acute toxicity test in which earthworms (Eisenia fetida) were exposed to the test substance, the NOEC was determined to be 250 mg/kg soil dry weight (d.w.) due to effects on the biomass of the organisms. No test item concentration showed >50% mortality so therefore the LC₅₀could not be calculated, but it can be concluded that the LC₅₀is >1000 mg/kg soil d.w., this being the highest concentration tested.

Reference 2

Endpoint:

toxicity to soil macroorganisms except arthropods: long-term

Data waiving:

study scientifically not necessary / other information available

Justification for data waiving:

other:

Description of key information

LC50>1000 mg/kg soil d.wt., NOEC=250 mg/kg soil d.wt., 14 day, earthworms, OECD 207, Zenz 2005

Additional information

In an acute toxicity test in which earthworms (Eisenia fetida) were exposed to the test substance the NOEC was determined to be 250 mg/kg soil d.wt due to effects on the biomass of the organisms. No test item concentration showed >50% mortality so therefore the LC50 could not be calculated, but it can be concluded that the LC50 is > 1000 mg/kg soil d.wt., this being the highest concentration tested.