Registration Dossier

Ecotoxicological information

Endpoint summary

Administrative data

Description of key information

Additional information

For the assessment of the terrestrial toxicity of MDIPA Esterquat C16-18 and C18 unsatd. an acute toxicity study in earthworms with the source substance MDEA-Esterquat C16-18 and C18 unsatd. and a toxicity study in plants with the source substance MDEA-Esterquat C16-18 and C18 unsatd. are available. A justification for read-across is given below.

 

Toxicity to soil macroorganisms

In a 14-day acute toxicity study, earthworms (Eisenia fetida) were exposed to MDEA-Esterquat C16-18 and C18 unsatd.  at 0, 2.20, 4.74, 10.2, 22.0, 47.4 mg a.i./kg dry soil (artifical soil). The experiment was carried out according to OECD TG 207. The 14 day LC50 value was determined to be >47.4 mg a.i./kg soil dry weight (nominal). The 14 d EC50 was >47.4 mg a.i./kg dry soil. The 14 d NOEC and LOEC, based on appearance and behaviour was >47.4 mg a.i./kg dry soil. No compound related toxicity effects were noted.

 

Toxicity to terrestrial plants

The effect of MDEA-Esterquat C16-18 and C18 unsatd. on seedling emergence and growth of the monocotyl oat (Avena sativa) and dicotyl lettuce (Lactuca sativa) crops was studied at nominal concentrations of 0 and 47.4 mg a.i./kg dry soil (1000 mg dispersion/kg dry soil). The study was conducted according to OECD TG 208. The growth medium used in the test was a mixture of natural soil and sand (1:1; pH 7.5; organic matter 1.1%). On day 17, the surviving plants per pot were recorded and cut at soil level for measuring the plant height and dry weight in the seedling emergence and vegetative vigour test, respectively. Seed germination was not affected by the MDEA-Esterquat C16-18 and C18 unsatd.  The 17 d NOEC based on seed germination was >47.4 mg a.i./kg dry soil. In the vegetative vigour test, the plant dry weight and plant height were not affected by MDEA-Esterquat C16-18 and C18 unsatd. treatment. The 17 d NOEC values based on plant growth (length and dry weight) was >47.4 mg a.i./kg dry soil.

 

Toxicity to soil microorganisms

According to REACH regulation (Annex IX, 9.4.2, column 2), toxicity testing with soil microorganisms does not need to be conducted. Testing can be substituted by the equilibrium partitioning method, based on aquatic tests. Testing shall be proposed if the results of the safety assessment indicate the need. Accumulation of the target substance in soil compartments (and thus, potential exposure of soil micro-organisms) is unlikely as the substance is readily biodegradable.

 

Toxicity to birds

No experimental data are available. According to REACH regulation (Annex XI, section 1), a long-term or reproductive toxicity study with birds does not need to be conducted as the biomagnification potential of the substance is expected to be low and secondary poisoning is unlikely.

 

Justification for read-across

Hypothesis for the analogue approach

This read-across is based on the hypothesis that source and target substances have similar ecotoxicological properties because they share structural similarities with common functional groups: quaternary amines, esters, and fatty acid chains with comparable length and degree of saturation. Furthermore, they are expected to hydrolyse to a comparable product (amine backbone) and common products (long chain fatty acids). This prediction is supported by ecotoxicological data on the substances themselves.

 

1. Substance Identity

The target substance MDIPA-Esterquat C16-18 and C18 unsatd. is a UVCB substance composed of diesters of mainly saturated C16 and C18 fatty acids with MDIPA (Methyldiisopropanol amine) as amine backbone.

The source substance MDEA-Esterquat C16-18 and C18 unsatd. is a UVCB substance composed of diesters of mainly saturated C16 and C18 fatty acids with MDEA (Methyldiethanol amine) as amine backbone (Table 1, Figure 1).

In the target and source substances, the amine function is further methylated resulting in a quaternary amine.

 

Table 1: Substance identities

 

Source substance

Target substance

MDEA-Esterquat C16-18 and C18 unsatd.

MDIPA-Esterquat C16-18 and C18 unsatd.

CAS number

1079184-43-2

NA

EC number

620-174-7

941-174-6

Chain length distribution

<C16: <7%

C16, 16‘, 17: 26-35%

C18: 42-52%

C18‘: 15-20%

C18‘‘, 18‘‘‘: </= 1.5%

>C18: </= 2%

< C16: <= 6%

C16 - < C18: 20-65%

C18: 4-60%

C18 unsatd.: 10-43%

> C18: <= 5%

Amine

MDEA

MDIPA

Anion

Chloride

Methyl sulphate

 

Figure 1: Structures of source substance (MDEA-Esterquat C16-18 and C18 unsatd.) and target substance (MDIPA-Esterquat C16-18 and C18 unsatd.), see attachment

 

2. Analogue approach justification

The read-across hypothesis is based on structural similarity of the target and the source substance. Based on available experimental data, including key physico-chemical properties and data from short-term ecotoxicity studies (fish, daphnia, algae), the read-across strategy is supported by a similar ecotoxicological profile of both substances.

The respective reliable data (RL 1 or 2) are summarised in the table below; robust study summaries are included in the Technical Dossier in the respective sections.

Ecotoxicological data are summarised in the data matrix.

 

2.1 Structural similarity

a. Structural similarity and functional groups

The target substance, MDIPA-Esterquat C16-18 and C18 unsatd., consists of an amine backbone (MDIPA = Methyldiisopropanolamine) esterified with long chain fatty acids C16, C18 and C18 unsaturated. The main reaction product is the dialkylester compound, besides that, small amounts of the monoalkylester may also be formed. The amine function is quaternised with two methyl groups. The counter ion is Methosulfate.

 

The source substance, MDEA-Esterquat C16-18 and C18 unsatd., consists of an amine backbone (MDEA = Methyldiethanolamine) esterified with long chain fatty acids C16, C18 and C18 unsaturated. The main reaction product is the dialkylester compound, besides that, small amounts of the monoalkylester may also be formed. The amine function is quaternised with two methyl groups. The counter ion is Chloride.

 

The source and the target substances share structural similarities with common functional groups (quaternary amines), esters, and fatty acid chains with comparable length and degree of saturation. The amine backbones based on MDEA and MDIPA, respectively, differ only by one methyl group in each chain. All functional groups are identical.

 

b. Common breakdown products

The ester bonds can be potentially hydrolysed, which would result in free fatty acids and Dimethyl-DEA (DEA = Diethanolamine) and Dimethyl-DIPA (DIPA = Diisopropanolamine), respectively. The fatty acids are expected to enter normal metabolic pathways and are therefore indistinguishable from fatty acids from other sources including diet.

 

c. Differences

Chloride is an essential ion present in all organisms; excess chloride is excreted (see common textbooks on biology / biochemistry). Methyl sulphate is metabolised to Sulphate and Carbon dioxide, and these are excreted via the urine and released by the lungs, respectively. The anions Chloride and Methyl sulphate are not expected to have any influence on toxicity or reactivity.

The methyl side chain of Dimethyl-DIPA, which is not present in Dimethyl-DEA, is not expected to enhance reactivity, which is supported by a similar ecotoxicological profile of the source and the target substance.

 

3. Physicochemical properties, environmental fate

Table 2: Physicochemical properties and environmental fate

Endpoints

Source substance

Target substance

MDEA-Esterquat C16-18 and C18 unsatd.

 

MDIPA-Esterquat C16-18 and C18 unsatd.

 

Molecular weight

697 g/mol


ca. 761 g/mol


Physical state at 20°C / 1013 hPa

solid (waxy)


solid (waxy)


Melting point

OECD Guideline 102; RL1; GLP

54°C

OECD Guideline 102; RL1; GLP

36°C

Boiling point

OECD Guideline 103; RL1; GLP

No boiling point up to 250°C

OECD Guideline 103; RL1; GLP

Decomposition at > 250°C

 

Surface tension

OECD Guideline 115; RL2, GLP

68.3 mN/m - not in line with the expected surface active behaviour of the substance

OECD Guideline 115; RL2, GLP

 

72 mN/m

at 20°C - not in line with the expected surface active behaviour of the substance

Water solubility

ASTM International E 1148 – 02, GLP, RL1

17.6 mg/L at 19.7°C

 

ASTM International E 1148 – 02; RL1, GLP

 

1.01 mg/L at 20°C

ASTM International E 1148 – 02, RL1; ISO17025

 

7.4 mg/L at 20±0.3°C

ASTM International E 1148 – 02, RL1; ISO17025

 

1.9 mg/L at 20±0.3°C

Log Kow

Determination technically not feasible due to the surface-active properties;read-across from DODMAC

3.8

Calculation based on Koc

 

 

 

4.43

Vapour pressure

Measurement is technically not feasible due to the substance properties; estimation

7.33E-18 Pa at 25°C

OECD Guideline 104, GLP; RL1

 

 

< 8.4E-07 Pa at 20°C

Biodegradation

OECD Guideline 301 B (Ready Biodegradability: CO2 Evolution Test), RL 2, GLP

 

readily biodegradable

OECD Guideline 301 B (Ready Biodegradability: CO2 Evolution Test) / OECD Guideline 301 F (Manometric Respirometry Test), RL 1, GLP

 

readily biodegradable

Biodegradation in water and sediment: simulation tests

OECD Guideline 303A, RL2; GLP

 

water: >99% removal on average during the 3 weeks removal period

No data, read-across

Draft OECD Guideline 314 (Simulation tests to assess the biodegradability of chemicals discharged in wastewate), RL2; no GLP

 

half life for mineralization: 18 – 24 hr

Hydrolysis as function of pH

No data (readily biodegradable)

OECD guideline 111; RL1, GLP

 

pH4:

t½= > 30 days at 20°C

t½= 53 days at 25°C

t½= 4.5 days at 50°C

t½= 1.8 days at 60°C

pH7:

t½= > 30 days at 20°C

t½= 25 days at 25°C

t½= 3.4 days at 50°C

t½= 1.7 days at 60°C

pH9:

t½= 84 days at 20°C

t½= 49 days at 25°C

t½= 4.2 days at 50°C

t½= 1.9 days at 60°C

Adsorption / Desorption

OECD Guideline 106 (Adsorption - Desorption Using a Batch Equilibrium Method); RL 1, GLP

 

for sludges: log Koc = 2.92

for soils: log Koc = 5.69

total: log Koc = 4.30

OECD Guideline 106 (Adsorption - Desorption Using a Batch Equilibrium Method); RL 1, GLP

 

for sludges: log Koc = 1.90,

for soils: log Koc = 4.89,

total: log Koc = 3.69

 

The molecular weights of the target and source substances are in a comparable range. Both substances are waxy solids with slightly different melting points (54°C vs. 36°C) which most probably results from minor structural differences (the methyl side chain of the Dimethyl-DIPA headgroup in the target substance, which is not present in the Dimethyl-DEA head-group in the source substance).

Experimental data on log Kow are not available for the source substance MDEA-Esterquat C16-18 and C18 unsatd. A read-across approach from the structurally similar substance DODMAC (Dimethyldioctadecyl ammonium chloride) was applied, resulting in a log Kow of 3.8. For the target substance MDIPA-Esterquat C16-18 and C18 unsatd. the log Kow of 4.43 was calculated based on the available Koc (organic carbon normalised adsorption coefficient).

Both substances have a very low vapour pressure. The differences in order of magnitude most probably result from the differences of the applied methods (measurement vs. estimation by calculation).

The results from the studies on surface tension with the source substance MDEA-Esterquat C16-18 and C18 unsatd. as well as the target substance MDIPA-Esterquat C16-18 and C18 unsatd. werenot in line with the expected surface tension behaviour of the test substances. Cationic surfactants carrying two C16/C18 alkyl chains, such as MDEA-Esterquat C16-18 and C18 unsatd. or MDIPA-Esterquat C16-18 and C18 unsatd., are designed to possess surface active properties and typically exhibit surface tension values as low as 27 mN/m. However, at temperatures of 20°C, the inner-molecular mobility of the fatty acid C-chains is hindered. Corresponding to this hinderance, on the one hand, the time to reach solubilisation equilibrium is long and on the other hand, there is a tendency to form vesicles. This can be seen i.e. at the test on hydrolysis with low correlation rates for pseudo-first order curve determination for 20°C but high correlation rates at 50 and 60°C.The result obtained with the source substance MDIPA Esterquat C18 unsatd. of 37.5 mN/m at 20°C was in the expected range for substances with this structure.

There are, however, differences in water solubility. Water solubility was determined by measurement of turbidityinstead of analytical determination of concentration, since no suitable method was available to remove undissolved test substance. The standard tests for this endpoint are intended for single substances and are not appropriate for these complex substances. It is stated in the OECD guideline 105 (1995) that:“The water solubility of a substance can be considerably affected by the presence of impurities. This guideline addresses the determination of the solubility in water of essentially pure substances […]”. Although impurities are per definition not present in UVCB substances, the complex and variable composition of the target and source substances may nevertheless influence the outcome in a similar manner.

Due to differences in the methodological approach the results for the water solubility measurement are not directly comparable between MDEA- and MDIPA-Esterquats. For the source substance MDEA-Esterquat C16-18 and C18 unsatd. the solubility of the test substance in water is considered equal to the intercept with the x-axis. Whereas for MDIPA-Esterquat C16-18 and C18 unsatd. a baseline turbidity was calculated, and the intercept with this baseline wasconsidered to represent the water solubility.

Both substances were readily biodegradable. The log Koc was in a comparable range for both substances.

 

4. Metabolism

An enzymatic degradation study is not available, neither for the target substance nor for the source substances. However, data from metabolism studies (human health endpoints) with the source substance MDEA-Esterquat C16-18 and C18 unsatd. suggest ester hydrolysis. The toxicokinetics assessment is based on the available experimental data, on structural similarities and on physicochemical properties. Esterases are abundant in all organisms and ester hydrolysis is a metabolic pathway which is also present in aquatic organisms. Thus, it can be assumed, that the available toxicokinetic data from human health endpoints are also relevant for environmental endpoints.

The source and target chemicals indicate similarity in toxicokinetic behaviour based on the molecular weight of 697 g/mol (MDEA-Esterquat C16-18 and C18 unsatd.) and 761 g/mol (MDIPA-Esterquat C16-18 and C18 unsatd.) and very low vapour pressures of 1E-09 Pa at 20°C (MDEA-Esterquat C16-18 and C18 unsatd. ) and 8.4E-07 Pa at 20°C (MDIPA-Esterquat C16-18 and C18 unsatd.) as it is shown in Table 2.

A measured log Kow for the source substance MDEA-Esterquat C16-18 and C18 unsatd. is not available, instead a read-across from a structurally similar substance has been applied, resulting in a log Kow of 3.8 for both source substances. The log Kow of the target substance MDIPA-Esterquat C16-18 and C18 unsatd. is 4.43 (calculated from the Koc).

The water solubilities of MDEA-Esterquat C16-18 and C18 unsatd. (17.6 mg/L at 19.7°C) and MDIPA-Esterquat C16-18 and C18 unsatd. (mean:3.4 mg/L at 20°C) are in a similar order of magnitude. The differences are explained above.

 

5. Comparison of data from ecotoxicological endpoints

5.1 Ecotoxicity data of the target and source substances

As described above as well as in the data matrix below, short-term aquatic toxicity data obtained in fish, daphnia and algae of the target substance MDIPA-Esterquat C16-18 and C18 unsatd.are in a similar range as short-term toxicity data ofthe source substance MDEA-Esterquat C16-18 and C18 unsatd.

 

Quality of the experimental data of the analogues:

All available studies have been conducted according to or are comparable with OECD guidelines and thus have been assigned a reliability of 1 or 2 as documented in the data matrix.

 

Classification and labelling

Table 3: Classification and labelling for target and source substances

 

 

Source substance

Target substance

Classification

Endpoints

MDEA-Esterquat C16-18 and C18 unsatd.

MDIPA-Esterquat C16-18 and C18 unsatd.

Physical

hazards

No classification required

No classification required

Hazards to the aquatic environment

Aquatic Chronic 3
H412: Harmful to aquatic life with long lasting effects.

Aquatic Chronic 3
H412: Harmful to aquatic life with long lasting effects.

Hazardous to the ozone layer

No classification required

No classification required

Acute toxicity

oral

No classification required

No classification required

Acute toxicity

dermal

No classification required

No classification required

Acute toxicity

inhalation

No classification required

No classification required

Skin irritation

No classification required

Skin irritation 2

H 315 Cause skin irritation

Eye irritation

No classification required

Eye irritation 2

H 319 Cause serious eye irritation

Sensitisation

No classification required

No classification required

Reproductive

toxicity

No classification required

No classification required

Germ cell

mutagenicity

No classification required

No classification required

Carcinogenicity

No classification required

No classification required

 

Concerning hazards to the aquatic environment, the source substance MDEA-Esterquat C16-18 and C18 unsatd. is classified as Aquatic Chronic 3.Based on the read-across approach, this classification is also relevant for the target substance MDIPA-Esterquat C16-18 and C18 unsatd.

 

6. Conclusion

Adequate and reliable scientific information indicates that the source substance MDEA-Esterquat C16-18 and C18 unsatd. and the target substance MDIPA-Esterquat C16-18 and C18 unsatd. have similar ecotoxicity profiles. Short-term toxicity data obtained in fish, daphnia and toxicity data from algae are comparable. Both substances are readily biodegradable and show a similar adsorption/desorption behaviour.

The structural similarities between the source and the target substance and the expected similarities of their breakdown products as presented above further support the read-across hypothesis.

Therefore, based on the available data, it can be concluded that the results of the Earthworm acute toxicity test, as well as the Seedling Emergence and Seedling Growth Test with the source substance are likely to predict the properties of the target substance and are considered as being adequate to fulfil the information requirement of Annex IX, 9.4.1 and Annex X, 9.4.6.

 

Data Matrix

Data matrix 1: General ecotoxicological profiles for MDEA-Esterquat C16-18 and C18 unsatd. and MDIPA-Esterquat C16-18 and C18 unsatd.

 

Source substances

Target substance

Endpoints

MDEA-Esterquat C16-18 and C18 unsatd.

MDIPA-Esterquat C16-18 and C18 unsatd.

Short-term toxicity to fish

 

OECD TG 203 (Fish, Acute Toxicity Test), Danio rerio, RL 2 (no analytical monitoring), GLP

 

96 h LC50 = 5.2 mg/L (nominal); 95% CL 4.4-6.3 mg/L

 

OECD TG 236 (Fish Embryo Acute Toxicity (FET) Test), Danio rerio, RL 1, GLP

 

96 h LC50 = 11.7 mg/L (meas., geom. mean); 95% CL 9.91-13.8 mg/L

Long-term toxicity to fish

US EPA TSCA, 40 CFR, Part 797.1600 (Early Life-Stage Toxicity), Pimephales promelas, RL 2, GLP

 

35 d NOEC = 0.686 mg/L (meas., not specified) based on length, weight, post-fry reduction mortality

No data, read-across

Short-term toxicity to aquatic invertebrates

 

OECD TG 202 (Daphnia sp. Acute Immobilisation Test); Daphnia magna, RL 2 (no analytical monitoring), GLP

 

24 h EC50 = 14.8 mg/L (nominal); 95% CL 8.4 - 26.2 mg/L

 

 

 

OECD TG 202 (Daphnia sp. Acute Immobilisation Test); Daphnia magna, RL 1, GLP

 

24 h EC50 = 13 mg/L (nominal); 95% CL 11 – 16 mg/L

 

48 h EC50 = 6.7 mg/L (nominal); 95% CL 5.8 - 8.0 mg/L

 

OECD TG 202 (Daphnia sp. Acute Immobilisation Test); Daphnia magna, RL 2, non-GLP

 

48 h EC50 =13.69 mg/L(nominal); 95% CL12.03 - 15.58mg/L

Long-term toxicity to aquatic invertebrates

EPA OTS 797.1330 (Daphnid Chronic Toxicity Test), Daphnia magna, RL 2, GLP

 

21 d NOEC = 1 mg/L (meas., not specified) based on mortality, reproduction, growth

No data, read-across

Toxicity to aquatic algae and cyanobacteria

EPA OTS 797.1050 (Algal Toxicity, Tiers I and II),Pseudokirchnerella subcapitata, RL 3 (no analytical monitoring), GLP – supporting data

 

96 h ErC50 = 2.9 mg/L (nominal); 95% CL (<2.0 and 4.2 mg/L)

 

96 h NOEC < 2 mg/L (nominal)

 

 

OECD Guideline 201 (Alga, Growth Inhibition Test),Pseudokirchnerella subcapitata, RL 1, GLP

 

 

72 h ErC50 = 8.1 mg/L (meas., TWA); 95% CL 6.4-10 mg/L

 

72 h ErC10 = 3.2 mg/L (meas., TWA); 95% CL 2.5-4.1 mg/L

 

72 h NOEC = 2.7 mg/L (meas., TWA), based on growth

 

72 h EbC50 = 4.4 mg/L (meas., TWA); 95% CL 1.6-12 mg/L

 

72 h EbC10 = 1.3 mg/L (meas., TWA); 95% CL 0.45-3.7 mg/L

 

72 h NOEC = 0.91 mg/L (meas., TWA), based on biomass

Toxicity to microorganisms

OECD TG 209 (Activated Sludge, Respiration Inhibition Test), RL 2, GLP

 

3 h NOEC > 47.4 mg/L (nominal)

 

OECD TG 301 B (Ready Biodegradability: CO2 Evolution Test), RL 1, GLP

 

14 d NOEC >/= 28 mg a.i./L

OECD TG 301 B (Ready Biodegradability: CO2 Evolution Test), RL 1, GLP

 

11 d NOEC >/= 24.3 mg a.i./L

OECD TG 301 F (Ready Biodegradability: Manometric Respirometry Test), RL 1, GLP

 

14 d NOEC >/= 460 mg a.i./L

Toxicity to soil macroorganisms except arthropods

OECD Guideline 207 (Earthworm, Acute Toxicity Tests), RL1, GLP

 

14 d LC50>47.4 mg a.i./kg dry soil

14 d EC50>47.4 mg a.i./kg dry soil

14d-NOEC and LOEC, based on appearance and behavior: > 47.4 mg act. ingr./kg dry soil (nominal each)

No data, read-across

Toxicity to terrestrial plants

OECD Guideline 208 (Terrestrial Plants Test: Seedling Emergence and Seedling Growth Test), RL1, GLP

 

17 d NOEC based on seed germination: >47.4 mg a.i./kg soil dw

17 d NOEC values based on plant growth (length and dry weight): >47.4 mg a.i./kg soil dw

No data, read-across