N-(2-nitrophenyl)phosphoric triamide

Toxicity to soil macroorganisms except arthropods

Link to relevant study record(s)

Reference

Endpoint:

toxicity to soil macroorganisms except arthropods: short-term

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2005-02-23 - 2005-04-19

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 207 (Earthworm, Acute Toxicity Tests)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

no

Vehicle:

no

Details on preparation and application of test substrate:

An exactly weighed amount of of the test item was mixed with finely ground quartz sand, immediately prior to application. This stock mixture was diluted with quartz sand in a way that 10 g of the mixture contained the amount test item required for one test vessel to adjust the selcted concentration. Treated substrate was thoroughly mixed using a laboratory mixer.
Preparation of the test Substrate
The preparation of the test Substrate based on a wet weight of artificial soil/vessel of 750.6 g. Based on a water content of 35 %, the soil dry weight per vessel was 556 g artificial soil.
1. 546 g soil dry weight (556 g artificial soil - 1 0 g quartz sand) was prepared for each replicate of each test item concentration. 2. 194.6 g water was added to each 546 g soil dry weight, resulting in 740.6 g wet weight (at 35 % dry weight nominal water content). The soil was made with dried ingredients and was therefore at nominal 0 % moisture before mixing the components. 3. 10 g test item quartz sand mixture containing the required amount of the test item were added to each prepared amount of artificial soil, resulting in test Substrate concentrations of 100 and 1000 mg P 101/04/kg d.w., with final nominal moisture content 35 % dry weight. 4. The final water content was then checked to be 35 %.

Test organisms (species):

Eisenia fetida

Animal group:

annelids

Details on test organisms:

Test organism: earthworm Eisenia fetida BOUCHE
Origin of the test organism:
originally purchased from “W. Neudorff GmbH KG“, An der Mühle 3, D-31860 Emmerthal
Breeding wider laboratory conditions
Breeding medium: mixture of horse manure, straw, peat (1:1:1); all ingredients were free from pesticide treatments
Breeding conditions: breeding cages (50 cm x 40 cm x 30 cm) constant diffuse light temperature: approximately 20 °C moist soil pH: approximately 7
Age of animals used in the test: adult worms (approximately 4 months old with clitcllum)
Time for acclimatisation to test conditions: approximately 24 hours
Weight of animals used in the test: 310 - 449 mg/worm

Study type:

laboratory study

Substrate type:

artificial soil

Limit test:

no

Total exposure duration:

14 d

Test temperature:

18-21 °C

pH:

6

Moisture:

34.0- 34.3 %

Details on test conditions:

Test vessel: clear glass Container with clear glass lid (volume: 1 litrc)
Number of animals/ vessel (- replicate): 10
Number of replicate s/ treatment group: 4
Number of animals/ treatment group: 40 The test vessels were placed at random in the test room.
Artificial soil
Composition of the artificial soil:
10 % Sphagnum peat 20 % kaolinite clay 0.5 % calcium carbonate 69.5 % industrial quartz sand (more than 50 % of the particles between 0.05 mm and 0.2 mm) deionised water
Laboratory mixer: K 45 SS (KitchenAid Inc.; St. Joseph Michigan, USA) mixing time: 2 x 1 minute for each replicate rotations per minute: 240
Amount/test vessel: approximately 750 g wet weight corresponding to 556 g dry weight of artificial soil with approximately 35 % water content

Nominal and measured concentrations:

100, 1000 mg test item/kg soil dry weight

Reference substance (positive control):

yes

Remarks:

2-chloroacetamide

Key result

Duration:

14 d

Dose descriptor:

NOEC

Effect conc.:

100 ng/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality

Key result

Duration:

14 d

Dose descriptor:

LC50

Effect conc.:

> 1 000 ng/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality

Results with reference substance (positive control):

To verify the sensitivity of the test System, the reference item 2-chloroacetamide was routinely tested at concentrations of 14.1, 18.3, 23.8, 31.0 and 40.4 mg a.i./kg d.w. In the most recent test with the reference item, dated 29.07.2004, the 14-day LC50 was calculated as 29.98 mg a.i./kg d.w. with 95 % confidence limits ranging from 28.85 to 31.16 mg a.i./kg d.w.

Treatment group	mg P 101/04/kg d.w.
	Control	100                    |			1000
Replicate	Initial fresh weight / worm [mg]।		mean	jer replicate)
1 2 3 4	360.9 368.3 382.0 384.5	363.2 367.4 377.6 392.5		369.4 371.0 372.6 389.8
mean	373.9	375.2		375.7
SD	11.2	13.0		9.5
cv %	3.0	3.5		2.5
	Fresh weight / worm [mg] after 14 days (mean per replicate)
1 2 3 4	328.6 344.4 338.1 352.7	325.9 338.2 332.0 336.1		292.4 310.3 307.6 307.3
mean	341.0	333.1		304.4
SD	10.2	5.4		8.1
cv %	3.0	1.6		2.7
	Biomass change (change in fresh weight after 14 da weight) weight / worm [mg] (mean per re]			ys relative to initial fresh □licate)
1 2 3 4	32.3 23.9 43.9 31.8	37.3 29.2 45.6 56.4		77.0 60.7 65.0 82.5
mean	33.0	42.1		71.3*
SD	8.2	11.6		10.2
	Biomass change (change	in fresh weight after 14 days relativ weight) [%] mean per replicate			e to initial fresh
1 2 3 4	8.9 6.5 11.5
384.5	363.2 367.4 377.6 392.5		369.4 371.0 372.6 389.8
mean	373.9	375.2		375.7
SD	11.2	13.0		9.5
cv %	3.0	3.5		2.5
	Fresh weight / worm [mg] after 14 days (mean per replicate)
1 2 3 4	328.6 344.4 338.1 352.7	325.9 338.2 332.0 336.1		292.4 310.3 307.6 307.3
mean	341.0	333.1		304.4
SD	10.2	5.4		8.1
cv %	3.0	1.6		2.7
	Biomass change (change in fresh weight after 14 da weight) weight / worm [mg] (mean per re]			ys relative to initial fresh □licate)
1 2 3 4	32.3 23.9 43.9 31.8	37.3 29.2 45.6 56.4		77.0 60.7 65.0 82.5
mean	33.0	42.1		71.3*
SD	8.2	11.6		10.2
	Biomass change (change	in fresh weight after 14 days relativ weight) [%] mean per replicate			e to initial fresh
1 2 3 4	8.9 6.5 11.5

Treatment group	mg P 101/04/kg d.w.
	Control	100	1000
Replicate	Number of surviving adult worms per replicate (14 davs after test initiation)
1	10	10	10
2	10	10	10
3	10	10	10
4	10	10	10
mean	10.0	10.0	10.0
SD	0.0	0.0	0.0
cv %	0.0	0.0	0.0
	Mortality (%)
mean	0.0	0.0	0.0

Validity criteria fulfilled:

yes

Remarks:

The validity criterion for the control group was accomplished: adult mortality: < 10 % (being 0 % after 14 days)

Conclusions:

In a 14-day toxicity study with P 101/04 on earthworm (Eisenia fetidd) the LC5Q was determined to be greater than 1000 mg P 101/04/kg soil dry weight, i.e. the highest concentration tested.
The NOEC was determined to be 100 mg P 101/04/kg soil dry weight.

Executive summary:

Effects of P 101/04 on survival and growth of the earthworm Eisenia fetida were determined at test concentrations of 100 and 1000 mg P 101/04/kg d.w. of artificial soil after an exposure period of 14 days. Three treatment groups including one quartz sand treated control group with four replicates each were tested.

At the beginning of the test, the fresh weight of the earthworms was in a ränge of 310 - 449 mg/earthworm. The physico-chemical parameters measured at the start and at the end of the test met the guideline requirements.

The maximum burrowing time was 5 minutes in the control group and in the P 101/04 treated groups.

The test item caused no mortality at the concentrations of 100 and 1000 mg P 101/04 /kg d.w. of artificial soil (table 3). No mortality (0 %) occurred in the control group.

No abnormal behaviour or toxic Symptoms of the worms were observed in any treatment or control group during the test.

Earthworm mean fresh weights were reduced by 8.8 % in the control and 11.2 % and 19.0 % for the 100 and 1000 mg P 101/04/kg d.w. treatment groups, respectively (table 2). The weight reduction was statistically significant (p < 0.05) relative to the control at the test item concentration of 1000 mg P 101/04/kg d.w.

The LC50 could not be calculated but it can be concluded that the LC50 is greater than 1000 mg P 101/04/kg soil dry weight.

Based on the Statistical evaluation of these results, the no-observed-effect-concentration (NOEC) was determined to be 100 mg P 101/04/kg soil dry weight.

Description of key information

In a 14-day toxicity study with P 101/04 on earthworm (Eisenia fetidd) the LC5Q was determined to be greater than 1000 mg P 101/04/kg soil dry weight, i.e. the highest concentration tested.

The NOEC was determined to be 100 mg P 101/04/kg soil dry weight.

Key value for chemical safety assessment

Short-term EC50 or LC50 for soil macroorganisms:

1 000 mg/kg soil dw