Tetrasodium N,N-bis(carboxylatomethyl)-L-glutamate

Toxicity to terrestrial plants

Administrative data

Endpoint:

toxicity to terrestrial plants: short-term (with study design considered suitable for long-term assessment)

Type of information:

experimental study

Adequacy of study:

key study

Study period:

from 2015-07 -13 to 2015-08-05

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Guideline study performed under GLP conditions with chemical analysis

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2015

Report date:

2015

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 208 (Terrestrial Plants Test: Seedling Emergence and Seedling Growth Test)

Deviations:

no

Principles of method if other than guideline:

No

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

051981-21-6

Cas Number:

051981-21-6

IUPAC Name:

051981-21-6

Constituent 2

Reference substance name:

N,N-bis(carboxymethyl)-L-glutamic acid tetrasodium salt

IUPAC Name:

N,N-bis(carboxymethyl)-L-glutamic acid tetrasodium salt

Test material form:

other: solution in water

Details on test material:

Chemical name: GLDA-Na4 aq. sol
Chemical name: L-glutamic acid N,N-diacetic acid tetrasodium salt
CAS No.: 051981-21-6
Batch Number: FC-C 11836
Active ingredient content: 47.5%
Appearance: Light yellow, clear liquid (max. 250 APHA)
Water solubility: Entirely soluble

Sampling and analysis

Analytical monitoring:

yes

Details on sampling:

At test start the stock solution and the control were analytically verified via LC-MS/MS with external standard calibration. At test end mixed soil samples (overall amount 10 - 20 g per treatment) were taken from the replicates of all concentration levels and the control and analytically determined via LC-MS/MS with external standard calibration.

Test substrate

Vehicle:

no

Details on preparation and application of test substrate:

A 2:1 mixture of natural soil LUFA 2.2 (batch number: Sp2.22415) and quartz sand (12a) was used.
Grain size: ≤2 mm
Carbon content: 1.1 %
pH-value: 6.11 ± 0.11
Origin
LANDWIRTSCHAFTLICHE UNTERSUCHUNGS- UND FORSCHUNGSANSTALT SPEYER (LUFA), Obere Langgasse 40, 67346 Speyer, Germany
DÖRENTRUP QUARZ GMBH Co. KG, An der Sandgrube 1, 31089 Duingen, Germany

Test organisms

1

Species:

Avena sativa

Plant group:

Monocotyledonae (monocots)

Details on test organisms:

(oats), Flämingsgold. Origin: KWS LOCHOW GMBH, Ferdinand-von-Lochow-Straße 5, 29303 Bergen, Germany

2

Species:

Brassica napus

Plant group:

Dicotyledonae (dicots)

Details on test organisms:

(rape), Kadore. Origin: KWS MAIS GMBH, Grimsehlstraße 31, 37574 Einbeck, Germany

3

Species:

Glycine max (G. soja)

Plant group:

Dicotyledonae (dicots)

Details on test organisms:

(soybean), Merlin. Origin: SAATBAU LINZ, A-4021 Linz, Schimmerstraße 19, P.O.B. 317, Austria

Study design

Test type:

seedling emergence toxicity test

Study type:

laboratory study

Substrate type:

other: A 2:1 mixture of natural soil LUFA 2.2 (batch number: Sp2.22415) and quartz sand (12a)

Limit test:

no

Total exposure duration:

21 d

Post exposure observation period:

During the 21 day observation period the plants were observed every 7 days for number of emerged seedlings, number of dead plants and visual phytotoxic effects. The rating of the treated plants was done in relation to the untreated control plants. Observations included all variations, either inhibitory or stimulatory, between the treated replicates and the untreated controls. Such variations may be phytotoxic symptoms (e.g. chlorosis, necrosis, wilting), formative effects of growth and development rates.
At the end of the study the shoot heights (in cm) and the shoot fresh weights of the shoots (in g) were measured additionally, directly after cutting the plants at the soil surface.
The shoot height was measured per plant. Average mean values per replicate were calculated. The shoot fresh weight was determined for all plants from the same pot and considered as one replicate.

Test conditions

Test temperature:

The room temperature was recorded continuously throughout the test with a thermohygrograph.

pH:

pH-value soil:6.11 ± 0.11

Moisture:

The relative humidity was recorded continuously throughout the test with a thermohygrograph.

Details on test conditions:

The test was conducted in a climatic hall.
The test conditions approximated those conditions necessary for normal growth or typical environmental conditions for the species and varieties tested. The following conditions (approximate ranges) are generally recommended:

Nominal and measured concentrations:

Oats:
nominal: 1000 - 320 - 100 - 32 - 10 - 3.2 mg/kg soil dry weight (DW)
geometric mean: 754 - 130 - 43 - 11 - 3.33 - 1.72 mg/kg soil dry weight
Rape, soybean:
nominal: 1000 mg/kg soil dry weight (DW)
geometric mean: 754 mg/kg soil dry weight

Reference substance (positive control):

no

Results and discussion

Effect concentrations

Effect concentrations 1

Species:

Avena sativa

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

754 mg/kg soil dw

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Remarks:

47.5% active ingredient

Basis for effect:

other: Shoot hight

Effect concentrations 2

Species:

Brassica napus

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

754 mg/kg soil dw

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Remarks:

47.5% active ingredient

Basis for effect:

other: Shoot hight

Effect concentrations 3

Species:

Glycine max (G. soja)

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

754 mg/kg soil dw

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Remarks:

47.5% active ingredient

Basis for effect:

other: shoot hight

Effect concentrations 4

Species:

Avena sativa

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

754 mg/kg soil dw

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Remarks:

47.5% active ingredient

Basis for effect:

seedling emergence

Effect concentrations 5

Species:

Brassica napus

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

754 mg/kg soil dw

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Remarks:

47.5% active ingredient

Basis for effect:

seedling emergence

Effect concentrations 6

Species:

Glycine max (G. soja)

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

754 mg/kg soil dw

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Remarks:

47.5% active ingredient

Basis for effect:

seedling emergence

Effect concentrations 7

Species:

Avena sativa

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

358.2 mg/kg soil dw

Nominal / measured:

meas. (geom. mean)

Conc. based on:

act. ingr.

Remarks:

Based on 100% active ingredient

Basis for effect:

seedling emergence

Effect concentrations 8

Species:

Brassica napus

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

358.2 mg/kg soil dw

Nominal / measured:

meas. (geom. mean)

Conc. based on:

act. ingr.

Remarks:

Based on 100% active ingredient

Basis for effect:

seedling emergence

Effect concentrations 9

Key result

Species:

Glycine max (G. soja)

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

358.2 mg/kg soil dw

Nominal / measured:

meas. (geom. mean)

Conc. based on:

act. ingr.

Remarks:

Based on 100% active ingredient

Basis for effect:

seedling emergence

Details on results:

At test end no test item related phytotoxic effects were determined for the tested plant species oats, rape and soybean up to the highest tested geometric mean measured test concentration of 754 mg/kg DW. The results of the control for all plant species met the required validity criteria. Therefore, the test is considered to be valid.

Results with reference substance (positive control):

No reference item is recommended for this test according to the guideline (OECD 208).

Reported statistics and error estimates:

One Way Analysis of Variance (ANOVA) was carried out for the determination of statistically significant differences compared to control replicates. When running a One Way Analysis of Variance, a Normality test and an Equal Variance test were done first. P-values for both, Normality and Equal Variance test, are 0.05. The alpha-value for ANOVA (acceptable probability of incorrectly concluding that there is a difference) is alpha = 0.05.
No EC-values were calculated because no effects ≥ 25 % occurred at test end.

Any other information on results incl. tables

 Measured Exposure Concentrations during the Definitive Test

 

The measured concentration of the stock solution at test start was110 %of the nominal values. Therefore nominal concentrations were taken into account for geometric mean calculation. As in the course of the study improvements on the analytical soil sample measurements were done, an extraction efficiency test with spiked soil was performed, revealing an extraction efficiency of 68 to 108 %.

On day 21, the extracted test item concentrations in the soil were between < SysQL and 57 % of the nominal values. This finding suits well the already reported biodegradability of the test substance class (Ginkel, 2007).

Values above LOD were taken into account for geometric mean calculations.

 

 Table39:       Measured Concentrations and Percentages of the Nominal Concentrations of the Test Item

Sampling date		2015-07-13		2015-08-03
Start of analysis		2015-07-13		2015-08-04
Nominal concentration		Dissolvine GL-47-S (CAS No.051981-21-6)
[mg/kg DW]	[g/L] (stock solution)	Meas. conc. [g/L]	%	Meas. conc. [mg/kg DW]	%	Geometric mean measured test item concentration [mg/kg DW]^2)
1000	25	27.5	110	569*	57	754
320	-	n.d.		53.0	17	130
100	-	n.d.		18.5	19	43.0
32.0	-	n.d.		3.78	12	11.0
10.0	-	n.d.		1.11^1)	11	3.33
3.20	-	n.d.		0.929^1)	11	1.72
Control	-	< SysQL		< SysQL		-

Measured concentration     = Measured concentration of the test item, dilution factor taken into account

*                                 = Reanalysed on 2015-08-05, mean value of two replicates and two injections each

%                                = Percentage of nominal concentration of the test item

SysQL                          =System Quantification Limit (0.5 mg/L test item)

1)                               = Values < SysQL but > LOD were calculated and taken into account for geometric mean calculation

2)                               = For geometric mean calculation, nominal values at the start of the exposure (verified via stock solution analysis) were taken                                   into account

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

The test is considered valid as all validity criteria have been fulfilled; Based on the test setup (GLP, Guideline study) and the extensive effort which has been paid to quantify the exposure not only at the start but also at the end of the study the results are considered to be reliable.

Executive summary:

The phytotoxicity of the test item GLDA-Na4 (CAS No. 051981 -21 -6) (batch number:FC-C11836) to three terrestrial plant species was determined in a seedling emergence and seedling growth test over a period of 21 days, from 2015-07-13 to 2015-08-05, with the definitive exposure phase from 2015-07-13 to 2015-08-03, according to OECD 208 (July 2006) at Dr.U.Noack-Laboratorien, 31157 Sarstedt, Germany.

 

Test systems comprised one monocotyledons (oats, Poaceae), and two dicotyledons (rape, Brassicaceae; soybean, Leguminosae).

 

The test was conducted with the following test concentrations:

Oats:                   nominal:               1000 - 320 - 100 - 32 -10 - 3.2 mg/kg soildry weight (DW)

                           geometric mean:   754 - 130 - 43 - 11 - 3.33 - 1.72 mg/kg soil dry weight

Rape, soybean:    nominal:               1000 mg/kg soil dry weight (DW)

                           geometric mean:   754 mg/kg soil dry weight

 

The results are given based on the geometric mean.

 

The test item was incorporated into the soil in which the seeds were sown afterwards. The test containers were bottom watered with nutrient solution as needed.

 

The toxic effects of the test item were determined on day 7, 14 and 21 by visual observations (number of emerged seedlings and phytotoxic effects) and on day 21 by shoot height and shoot fresh weight determination.

 

At test end no test item relatedphytotoxic effectswere determined for the tested plant species oats, rape and soybean up to the highest tested geometric mean measured test concentration of 754 mg/kg DW (section11.1.3).

 

The results in terms of shoot height(in cm) andbiomass(in g) at test end are presented in sections 11.3 and 11.4, respectively.

 

The statistically calculated NOEC values, as well as the calculated EC₂₅- and EC₅₀-values, are summarized in Table 1 to Table 3.

 

The results of the control for all plant species met the required validity criteria. Therefore, the test is considered to be valid.

 

The following results are given as geometric mean measured test concentrations.

 

Table 1:          Shoot Height:NOEC, EC₂₅- and EC₅₀-Values with Confidence Range (p)

Species		NOEC [mg/kg DW]		EC25 [mg/kg DW]		p = 95% [mg/kg DW]		EC50 [mg/kg DW]		p = 95% [mg/kg DW]
Oats		754		> 754		–		> 754		–
Rape		754		> 754		–		> 754		–
Soybean		754		> 754		–		> 754		–

 

 Table 2:          Shoot Fresh Weight: NOEC, EC₂₅- and EC₅₀-Values with Confidence Range (p)

Species		NOEC [mg/kg DW]		EC25 [mg/kg DW]		p = 95% [mg/kg DW]		EC50 [mg/kg DW]		p = 95% [mg/kg DW]
Oats		754		> 754		–		> 754		–
Rape		754		> 754		–		> 754		–
Soybean		754		> 754		–		> 754		–

 

 Table 3:          Number of Emerged Seedlings: NOEC, EC₂₅- and EC₅₀-Values with Confidence Range (p)

Species	NOEC [mg/kg DW]	EC25 [mg/kg DW]	p = 95% [mg/kg DW]	EC50 [mg/kg DW]	p = 95% [mg/kg DW]
Oats	754	> 754	–	> 754	–
Rape	754	> 754	–	> 754	–
Soybean	754	> 754	–	> 754	–

-)                                                                      Not determinable