N-[3-(dimethylamino)propyl]stearamide

Toxicity to terrestrial arthropods

Link to relevant study record(s)

Reference

Endpoint:

toxicity to terrestrial arthropods: long-term

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Justification for type of information:

REPORTING FORMAT FOR THE ANALOGUE APPROACH

1. HYPOTHESIS FOR THE ANALOGUE APPROACH
This read-across is based on the hypothesis that source and target substances have similar toxicological properties because
• they are manufactured from similar or identical precursors under similar conditions
• they share structural similarities with common functional groups: quaternary amines, amides, and saturated fatty acid chains with comparable length
• the metabolism pathway leads to comparable products (amine backbone and long chain fatty acids) and non-common products predicted to have no toxicological effects (long chain fatty acids).

Therefore, read-across from the existing ecotoxicity (sediment and soil) and environmental fate studies on the source substance is considered as an appropriate adaptation to the standard information requirements of the REACH Regulation for the target substance, in accordance with the provisions of Annex XI, 1.5 of the REACH Regulation.

For further details, please refer to attached read-across justification.

2. SOURCE AND TARGET CHEMICAL(S) (INCLUDING INFORMATION ON PURITY AND IMPURITIES)
Please refer to attached read-across justification.

3. ANALOGUE APPROACH JUSTIFICATION
Please refer to attached read-across justification.

4. DATA MATRIX
Please refer to attached read-across justification.

Reason / purpose for cross-reference:

read-across source

Test organisms (species):

Folsomia candida

Animal group:

Collembola (soil-dwelling springtail)

Study type:

laboratory study

pH (if soil or dung study):

Test item [mg/kg DW]
pH
Day 0 Day 28
Control 6.38 6.14
Solvent Control 6.43 6.32
62.5 6.44 6.32
125 6.44 6.29
250 6.44 6.32
500 6.44 6.28
1000 6.43 6.25

Humidity:

Test item [mg/kg DW]
Soil moisture [%]1)
Day 0 Day 14* Day 28
Control 40.49 39.28 37.98
Solvent Control 40.18 39.19 42.08
62.5 39.32 37.11 34.57
125 39.05 36.33 32.86
250 38.93 37.67 38.99
500 38.57 36.72 40.53
1000 39.03 36.62 33.19
1 ) = Related to dry weight (DW) of the soil; maximum water holding capacity (WHC) = 71.5 g / 100 g DW
* ) = Due to difference > 2 %, additional moistening of the replicates with each 1 mL demin. water on day 16

Duration:

28 d

Dose descriptor:

NOEC

Effect conc.:

500 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality

Remarks:

and reproduction

Remarks on result:

other: n.a.

Duration:

28 d

Dose descriptor:

LOEC

Effect conc.:

1 000 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: reproduction, mortality

Remarks on result:

other: n.a.

Duration:

28 d

Dose descriptor:

LD50

Effect conc.:

> 1 000 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality

Remarks on result:

other: n.a.

Conclusions:

The No Observed Effect Concentration (NOEC) for mortality and reproduction was determined to be 500 mg/kg DW, the LOEC was determined to be 1000 mg/kg DW for adult mortality as well as for reproduction. The mean lethal and sub-lethal dose (LD50) was determined to be > 1000 mg/kg soil DW.

Description of key information

The No Observed Effect Concentration (NOEC) for mortality and reproduction was determined to be 500 mg/kg DW, the LOEC was determined to be 1000 mg/kg DW for adult mortality as well as for reproduction. The mean lethal and sub-lethal dose (LD50) was determined to be > 1000 mg/kg soil DW.

Key value for chemical safety assessment

Long-term EC10, LC10 or NOEC for soil dwelling arthropods:

1 000 mg/kg soil dw

Additional information

The effects of C20/22 ATQ trocken (Batch: DEG4047322) on the reproduction of Folsomia candida in artificial soil were examined in a laboratory study. The study was carried out based on ISO 11267 (1999) and OECD Draft (2008) at the Dr.U.Noack-Laboratorien, Käthe-Paulus-Str. 1, D-31157 Sarstedt, from 2008-04-18 to 2009-07-22.

The aim of the test was to determine the effects of the test item on the reproduction of Folsomia candida in artificial soil by cutaneous and alimentary uptake.The test item C20/22 ATQ trocken was incorporated once into artificial soil with the test item concentrations 62.5 – 125 - 250 – 500 – 1000 mg/kg DW. The control was artificial soil without the test or reference item. Additionally a solvent control was tested. Folsomia candida (12days old) were placed into artificial soil. For the control and solvent control 8 replicates and for the test item 5 replicates were tested. In each replicate 10 juveniles were inserted. During exposure springtails were fed with granulated dry yeast. After 28 days, mortality and reproduction were assessed.

Toxicity to Folsomia candida, Laboratory Test

Test item	C20/22 ATQ trocken
Test object	Folsomia candida
Exposure	Artificial soil
	Adult mortality	Reproduction
LOEC [mg/kg DW]	1000	1000
NOEC [mg/kg DW]	500	500
LD50/ EC50[mg/kg DW]	> 1000	> 1000

DW = Dry weight                                           CI = Confidence Interval

The validity of the study was evaluated according to ISO 11267 (1999) and OECD Draft (2008). Control mortality should be 20 %. In this study the mean control mortality (pooled controls) was 13.8 %. The reproduction rate should be >100 instars per control replicate. In this study the reproduction rate was between 245 and 670 instars per control replicate (pooled control).The coefficient of variation of the reproduction rate in the control should be 30.0 %. In this study the coefficient of variation in the pooled controls was 25 %. Thus, this study was considered to be valid.