Reaction products of phosphoryl trichloride and 2-methyloxirane

Toxicity to soil macroorganisms except arthropods

Link to relevant study record(s)

Reference

Endpoint:

toxicity to soil macroorganisms except arthropods: long-term

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2003

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Remarks:

GLP

Qualifier:

according to guideline

Guideline:

OECD Guideline 222 (Earthworm Reproduction Test (Eisenia fetida/Eisenia andrei))

Version / remarks:

Draft guideline (January 2000)

Deviations:

yes

Remarks:

1. Preliminary test: 2 replicate units were used instead of one 2. Final test: number of juveniles was assessed within 2 days instead of one. 3. Final test: temperature accidentally decreased down to 15.5 °C for a few hours

Principles of method if other than guideline:

The study w as conducted according to the approved study protocol, with the following changes:
1. Preliminary test : two replicate units were used for each TCPP concentration instead of one
2. Final test: the number of juveniles was assessed within two days instead of one. Half the replicates was asscssed at the end of the test period,
and half on the day after, so that the compared analysis was not biased.
3. Final test: the temperature accidentally decreased down to 15.5 °C for a few hours within the first week of the development of the juveniles.

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Details on sampling:

Three treatment solutions of the final test were assessed by GC-FID analysis.

Vehicle:

yes

Details on preparation and application of test substrate:

Test units consisted in 500 g oven dried artificial soil substrate incorporated in 1.5 to 2 L glass containers.
The composition of the soil substrate (dry w/w) was as follows:
- Sphagnum peat (grounded and sieved) 10 %
- Kaolinite clay 20 %
- Fine sand 70 %
1.8 g Calcium carbonate was added in each container that was previously calculated to allow a pH value of 6.0 (+- 0.5), on the control soil basis
It was no more adjusted in the presence of the test substance or when Carbendazim was added.
Few days before the initiation of the test, the sphagnum peat was grounded and sieved. Mean moisture was assessed from weight losses of 3 samplesafter drying. The results were espressed as grams of water per 100 g of each initial material.
Total water holding capacity of each material was measured according to the procedures outlined in ISO 1 1274 (1992) : Soil quality - Determination of the water retention characteristic - Laboratory methods.
Acetone is used as verhicle for TCPP for application to sand. After the acetone is evaporate the spiked sand is mixed thoroughly with soil.

Test organisms (species):

Eisenia fetida

Animal group:

annelids

Details on test organisms:

Origin : adult specimens born at the Phytosafe site, of the same generation, older than 2 months, and younger than one year.
Weight: between 300 and 600 mg:
The specimens involved in the tests were previously weighed in the breeding chamber. They were then distributed 10 by 10 in glass vials, ready for
their incorporation in the test units.

Study type:

laboratory study

Substrate type:

artificial soil

Limit test:

no

Total exposure duration:

56 d

Test temperature:

Preliminary test: mean = 22°C
Final test: 18.5 - 22 °C

pH:

6.6 - 6.8

Moisture:

46.7 - 49.0 %

Details on test conditions:

Organic matter content in the test soil was 10%.
Illumination: 16h light/ 8h dark
Light intensity: Preliminary test: 485-595 lux; Final test: 412-561 lux

Nominal and measured concentrations:

Nominal conc.: 31.36, 40.18, 52.91, 68.59, 89.17, 115.63, 150.90 and 195.98

Reference substance (positive control):

yes

Remarks:

Carbendazim

Duration:

28 d

Dose descriptor:

NOEC

Effect conc.:

>= 196 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality

Duration:

28 d

Dose descriptor:

NOEC

Effect conc.:

115.6 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: biomass

Duration:

28 d

Dose descriptor:

LOEC

Effect conc.:

150.6 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: biomass

Duration:

56 d

Dose descriptor:

EC50

Effect conc.:

70.7 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

reproduction

Remarks on result:

other: 95%CL: 58.7-85.0 mg/kg

Key result

Duration:

56 d

Dose descriptor:

NOEC

Effect conc.:

52.9 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

reproduction

Duration:

56 d

Dose descriptor:

LOEC

Effect conc.:

68.9 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

reproduction

Details on results:

Validity analysis of the test results
The test was considered as valid on the basis of:
Control mortality <10%
Loss of biomass in the control <20%
Initial pH of the control soil = 6.0 +/- 0.5
Moisture of the soil substrate = 40 to 60% total water holding capacity
Production of juveniles in the control > 30 per unit
Coefficient of variation of production in the control <30%
EC50 of carbendazim occurred within the limit range of 1-5 mg/kg

Reported statistics and error estimates:

Mean number of juveniles within each TCPP treatment group was calculated as percent to the control. Log percent number of juveniles was plotted against Log concentration of TCPP.
The regression curve was calculated for TCPP concentrations ranging between 52.91 and 150.90 mg/kg. The lowest treatment concentration was excluded (no effect occurred), as well as the highest one (the production ofjuveniles was zero).
The results of the 40.18 mg/kg treated group was excluded also: mean production of juveniles was abnormally low, due to replicate 1 where the juveniles were only 6. The phenomenon was not confirmed by higher treatment concentrations. The test unit was controlled twice,and the origin of the anomaly remained unknown.
The regression curve was calculated to be :
Logio(Percent juveniles to the control) = -1.599 (± 0.100) Log)0 (TCPP mg/kg) + 4.655 (± 0.196)
And r2 = 0.988.

Preliminary test: -No mortality occurred in any of the test unit for the control and for the test substance treated groups and the carbendazim groups, with only one exception. In a replicate of the test substance treated group 1 specimen died, but this phenomenon was not confirmed by higher test substance concentrations. -The production of cocoons did not appear to be affectd in any of the test substance groups as referred to the total number at the end of the 4 week-exposure period. -At the end of the exposure period, moisture of the control was 49.9% of the total water holding capacity of the artifical soil. - The pH was in the range of 6.9 to 7.0. -Final weight of the worms was reduced in the group treated with the highest concentration (50.84 mg/kg). The result was consistent with observations that showed that the ingestion of the food in these test units was delayed as compared to the solvent control group.

Table - Main test Biomass Deviation Throughout the 4-week Exposure Period

Treatment	Number of Replicates	Mean Bodyweight Deviation (%)
			Water Control	8	+2.3
Solvent Control	4	+4.1
31.36 mg/kg	4	+2.8
40.18 mg/kg	4	+9.0
52.91 mg/kg	4	+4.5
68.59 mg/kg	4	+2.2
89.17 mg/kg	4	-7.7
115.63 mg/kg	4	-9.3
150.90 mg/kg	4	-9.1
195.98 mg/kg	4	-7.4

Table - Number of Juveniles at the End of the Test period

Treatment	Replicates								Mean (SD)
	1	2	3	4	5	6	7	8
Water Control	34	31	39	47	31	37	47	52	39.8 (8.0)
Solvent Control	32	32	45	36	-	-	-	-	36.3 (6.1)
31.36 mg/kg	31	42	26	45	-	-	-	-	36.0 (6.1)
40.18 mg/kg	6	29	19	30	-	-	-	-	21.0 (11.2)
52.91 mg/kg	22	36	22	52	-	-	-	-	33.0 (14.3)
68.59 mg/kg	11	23	10	30	-	-	-	-	18.5 (9.7)
89.17 mg/kg	7	20	10	21	-	-	-	-	14.5 (7.1)
115.63 mg/kg	0	4	22	11	-	-	-	-	9.3 (9.6)
150.90 mg/kg	0	0	13	10	-	-	-	-	5.8 (6.8)
195.98 mg/kg	0	0	0	0	-	-	-	-	0.0 (0.0)

 

Validity criteria fulfilled:

yes

Remarks:

Control mortality: Loss of biomass in control; Initial pH of control; Moisture of soil substrate; Production of juveniles in control; Coefficient of variation of production in control; EC50 of carbendazim occurred within the limit range of 1-5 mg/kg

Conclusions:

A 56-day NOEC (28-day adult plus 28-day juvenile exposure period) of 53 mg/kg dwt for earthworm reproduction has been determined for TCPP.

Executive summary:

Long-term effects of TCPP on the reproductive performance of earthworms (Eisenia fetida) was determined in a study performed in compliance with the OECD draft guideline 222: Earthworm Reproduction Test. Deviations from guideline were; - Preliminary test: two replicate units were used for each TCPP concentration insted of one - Final test: the number of juveniles was assessed within two daysnstead of one. Half the replicates was assessed at the end of the test period, and half on the day after, so that th compared analysis was not biased. Final test: Accidently, the temperature edcrease down to 15.5 °C for a few hours within the firt week of the development of juveniles. Under laboratory conditions, a NOEC of 53 mg/kg dwt has been determined after 56 days of exposure, (28-day adult plus 28-day juvenile exposure period) (Servajean, 2002). The test fulfilled the criteria for acceptability for determining a PNEC. An analytical monitoring of TCPP is performed (GC-FID) leading to recoveries reaching from 98.1% to 101.0%. Due to thsi high recoveries given effect values are based on nominal concentrations.

Description of key information

OECD 222 (Servajean, 2003): NOEC = 53 mg/kg dw
A normalised NOEC of 18.02 mg/kg dw  for TCPP was determined in a long-term study with respect to the reproductive performance of earthworms.

Key value for chemical safety assessment

Long-term EC10, LC10 or NOEC for soil macroorganisms:

18.02 mg/kg soil dw

Additional information

Long-term effects of TCPP on the reproductive performance of earthworms (Eisenia fetida) was determined in a study performed in compliance with the OECD draft guideline 222: Earthworm Reproduction Test. Under laboratory conditions, a NOEC reproduction of 53 mg/kg dwt has been determined after 56 days of exposure, (28-day adult plus 28-day juvenile exposure period) (Servajean, 2002).

As the organic matter content was approximately 10% (sphagnum moss peat 10% w/w dry weight of test soil), the result needs to be corrected to obtain a result relevant for natural soils, containing a default of 3.4% organic matter, as recommended in the guidance document on information requirements and chemical safety assessment, Chapter R.10. A correction factor of 0.34 is therefore applied, giving a normalised result of 56-day NOECnormalised 18.02 mg/kg dry weight.