6,6',6''-(1,3,5-triazine-2,4,6-triyltriimino)trihexanoic acid, compound with 2,2',2''-nitrilotriethanol (1:3)

Toxicity to aquatic algae and cyanobacteria

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

toxicity to aquatic algae and cyanobacteria

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2012

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Guideline study with detailed documentation

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Alga, Growth Inhibition Test)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Remarks:

EL

Analytical monitoring:

yes

Details on sampling:

- Sampling method: algae separated by centrifugation before analysis

Vehicle:

no

Test organisms (species):

Desmodesmus subspicatus (previous name: Scenedesmus subspicatus)

Details on test organisms:

TEST ORGANISM
- Strain: G. Brinkmann 1953/SAG86,81
- Source: Institute of Botany, Slovak Academy of Sciences, Bratislava, Slovak Republic
- Method of cultivation: inoculum culture prepared 3 days before test start. Conditions same as under test.

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

72 h

Test temperature:

22 - 24 °C

pH:

7.98 - 8.16

Nominal and measured concentrations:

Initial concentrations: 64, 128, 256, 512, 1024, 2048, 3000 mg/L (nominal)
Measured concentrations at start and end of the test: between -0.27% and +9.91% deviation of nominal

Details on test conditions:

TEST SYSTEM
- Test vessel: 50 mL volume in 150 mL flasks
- Type: closed with air-permeable stoppers
- Materia: glass or other chemically inert material
- Initial cells density: 4160 cells/mL
- No. of vessels per concentration (replicates): 3
- No. of vessels per control (replicates): 6

GROWTH MEDIUM
- Standard medium used: yes, according to OECD

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Sörensen buffer
- Intervals of water quality measurement: pH measured at beginning and end of test

OTHER TEST CONDITIONS
- Sterile test conditions: yes
- Adjustment of pH: stock solution adjusted with 1 N NaOH to pH 8.04
- Photoperiod: continuous illumination
- Light intensity and quality: 8470 - 8590 lux, cool white light, effective wavelength 400 - 700 nm

Reference substance (positive control):

yes

Remarks:

potassium dichromate

Duration:

72 h

Dose descriptor:

EC10

Effect conc.:

145 mg/L

Nominal / measured:

meas. (initial)

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other: 95% CI: 115-181 mg/L

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

3 285 mg/L

Nominal / measured:

meas. (initial)

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other: 95% CI: 2619-4119 mg/L

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

452 mg/L

Nominal / measured:

meas. (initial)

Conc. based on:

test mat.

Basis for effect:

biomass

Remarks on result:

other: 95% CI: 247-825 mg/L

Results with reference substance (positive control):

- 72 h-ECr10: 0.32 mg/L (mean of 3 determinations)
- 72 h-ECr50: 0.81 mg/L (mean of 3 determinations)

Reported statistics and error estimates:

y

Growth data:

Nominal concentration [mg/L]	Inhibition of growth rate [%]	Inhibition of biomass [%]
64	1.00	4.4
128	6.71	21.2
256	18.11	42.3
512	25.66	60.8
1024	34.24	72.3
2048	43.65	76.9
3000	50.03	83.9

 

Validity criteria fulfilled:

yes

Executive summary:

A growth inhibition test of TC to the algae Desmodesmus subspicatus was performed according to OECD 201. After 72 h of exposure, the EC_r10 was determined to be 145 mg/L and the EC_r50 to be 3285 mg/L.

Reference 2

Endpoint:

toxicity to aquatic algae and cyanobacteria

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Test procedure in accordance with national standard methods (DIN 38412, part 9); peer-reviewed data from reliable database; legally binding classification (KBwS, WGK 1)

Qualifier:

according to guideline

Guideline:

other: German Industrial Standard DIN 38412 part 9

GLP compliance:

not specified

Analytical monitoring:

no

Vehicle:

not specified

Test organisms (species):

Desmodesmus subspicatus (previous name: Scenedesmus subspicatus)

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

96 h

pH:

tested in neutralised and non-neutralised test medium in parallel

Details on test conditions:

- algae test apparatus with quasi-continuous determination of optical density      
- counting of cell numbers     
- photometric determination of turbidity at pre-determined times     
- test solutions tested non-neutralized and neutralized

Reference substance (positive control):

no

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

512 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Remarks:

neutralised

Basis for effect:

growth rate

Duration:

72 h

Dose descriptor:

EC10

Effect conc.:

26 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Remarks:

neutralised

Basis for effect:

growth rate

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

216 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Remarks:

non-neutralised

Basis for effect:

growth rate

Duration:

72 h

Dose descriptor:

EC10

Effect conc.:

7.9 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Remarks:

non-neutralised

Basis for effect:

growth rate

Validity criteria fulfilled:

yes

Description of key information

The compound consists of a triazine part and an amine part. Under environmental conditions it is present in its dissociated form. Therefore, separate assessments were conducted for the triazine and the amine part, respectively.  

CAS 80584-91-4: There is a high probability that the compound is not acutely harmful to algae.  

CAS 102-71-6: There is a high probability that the compound is not acutely harmful to algae.

Additional information

The compound consists of a triazine part and an amine part. Under environmental conditions it is present in its dissociated form. Therefore, separate assessments were conducted for the triazine and the amine part, respectively.

CAS 80584-91-4

Effects to alga was assessed in a 72-h growth inhibition test with Desmodesmus subspicatus in accordance to OECD guideline 201. The test was conducted with concentrations of 64, 128, 256, 512, 1024, 2048, 3000 mg/L.

ErC10 = 145 mg/L, ErC50 = 3285 mg/L, Ey50 = 452 mg/L

CAS 102-71-6

The assessment of the algal toxicity is based on effect data taken from the “Commission for the Evaluation of Substances Hazardous to Waters” (KBwS) data sheet no. 201, which is part of the German Federal Water Act (Article 19g). Based on the collected data a substance is classified according to its water-hazardous properties (WGK 1 to 3). Triethanolamine was classified as WGK 1, which indicates a low hazard to waters. As the list with the classified substances was published in the Bundesanzeiger (Ref. 4), the classification is legally binding for the industry.

 

The data sheet lists three sources for effect data on algae (see table below) of which only one was performed according to a national standard method (Amann & Steinhäuser, Ref. 1) while the other two are of questionable reliability due to exposure period or documentation (Bringmann & Kühn, Ref. 2; Verschueren, Ref. 8).

 

Species	Not neutralised		Neutralised		Remark	Ref.
	EC10 (mg/L)	EC50 (mg/L)	EC10 (mg/L)	EC50 (mg/L)
Desmodesmus subspicatus	7.9	216	26	512	DIN 38412, part 9; exposure: 72 h; based on growth rate	1
Scenedesmus quadricauda	EC3: 1.8	-	EC3: 715	-	Confusion between results for neutralised and not neutralised test results; here displayed correctly; exposure: 8 d (non-standard duration); no guideline followed	2
Scenedesmus	EC0: 100	-	-	-	No information regarding exposure duration and conditions; test species not clearly identified; based on growth rate	8
Additional information
Phaeodactylum tricornutum	> 10; NOEC: < 28	204	-	-	Seawater species, ISO 10253; exposure: 72 h with light/dark cycle 16/8 h	7
Skeletonema costatum	-	>107 -<260	-	-	Seawater species, ISO 10253; exposure: 72-h, constant light	9, 10
Desmodesmus subspicatus	-	-	110	750	DIN 38412, part 9; exposure: 48 h	6
Colpoda	EC0: 160	-	-	-	No information regarding exposure duration and conditions; test species not clearly identified; based on growth rate	8

 

The data from Amann & Steinhäuser (Ref. 1) were generated within the research project “Assessment of Water-Hazardous Substances” which served the scientific support and administration of a “Commission” in their work of the German Federal Ministry for the Environment, Nature Conservation and Nuclear Safety.

 

The algal toxicity tests were performed according to DIN 38412, part 9 (draft). Tests were performed in neutral medium unless noted otherwise. In case of triethanolamine, the test was performed with neutralised and not neutralised test medium in parallel. The test species wasScenedesmus subspicatus(new name:Desmodesmus subspicatus). The EC10 was determined being the relevant factor for the WGK classification. The effect data were evaluated based on growth rate in accordance with the information requirements of REACH.

 

The effect values show a higher toxicity using non-neutralised test medium; therefore, part of the observed toxicity is caused by the pH change due to the substance. For the risk assessment the effect data for the neutralised test medium should be used.

 

Detailed data on the study itself, e.g. biomass growth rate as well as growth curves are not available. Nevertheless the test results were performed according to national standards and peer-reviewed by the KBwS during the performance of the research project. Therefore, the data can be regarded as reliable with restrictions (RL 2) and should be used as key study for the risk assessment.

 

The result by Amann & Steinhäuser (1) is supported by the published effect values for a seawater algaePhaeodactylum tricornutumby Libralato et al. (2010) and the information on the seawater algae Skeletonema costatum published by Eide-Haugmo et al. (2009/2012). Other data which are available for triethanolamine do not contradict the selected key values, but should not be used for risk assessment purposes due to insufficient exposure duration and documentation.

 

The study performed by Amann & Steinhäuser was identified as key study. A 72-h ErC50 of 216 mg/l for non-neutralized samples and a 72-h ErC50 of 512 mg/l for a neutralized sample were determined onDesmodesmus subspicatusaccording to German Industrial Standard DIN 38412, part 9 (draft). The corresponding ErC10 values are 7.9 (non-neutr.) and 26 mg/L (neutr.). This result is supported by published data on a seawater algae (Phaeodactylum tricornutum; Libralato et al., 2010), which gave similar effect values in non-neutralised test solutions: EC50 = 204 mg/L; EC10 > 10 mg/L; NOEC < 28 mg/L. In addition, the seawater algae Skeletonema costatum (Eide-Haugmo et al., 2009/2012) also supports this level of sensitivity, although the EC50 could only be determined as a range of > 107 and < 260 mg/L.

 

Based on the presented data, it can be concluded that triethanolamine is acutely not harmful to algae.

 

References

1)     Amann W. & Steinhäuser KG (1986, 1988). 1. und 2. zusammenfassender Zwischenbericht zum F+E Vorhaben „Bewertung wassergefährdender Stoffe“ Teil I (FV-Nr. 82-102 05 308); Bayerisches Landesamt für Wasserwirtschaft, München [Interim Report, Evaluation of substances hazardous to water].

2)     Bringmann G. & Kühn R. (1977). Z Wasser Abwasser Forsch 10, 87-98.

3)     DIN 38412, part 9 (draft). German standard methods for the examination of water, waste water and sludge; bio-assays (group L); determination of the inhibitory effect of water constituents on the growth ofScenedesmusgreen algae (L 9).

4)     Federal Ministry of Justice (2005). Bundesanzeiger No. 142 a.

5)     ISO, Standard 10253 (2006). Water Quality—Marine Algal Growth Inhibition Test withSkeletonema costatumandPhaeodactylum tricornutum.

6)     Kühn R and Pattard M (1990). Results of the harmful effects of water pollutants to green algae (Scenedesmus subspicatus) in the cell multiplication inhibition test. Water Research 24(1), 31-38.

7)     Libralato G., Volphi Ghirardini A., Avezzù F. (2010). Seawater ecotoxicity of monoethanolamine, diethanolamine and triethanolamine. J Hazardous Materials 176, 535-539.

8)     Verschueren K. (1983). Handbook of environmental data on organic chemicals, 2nd edition. Van Nostrand Reinhold Company, New York.

9) Eide-Haugmo I, Brakstad OG, Hoff KA, Sorheim KR, Falck da Silva E, Svendsen HF (2009). Environmental impact of amines. Energy Procedia 1: 1297-1304.

10) Eide-Haugmo I, Brakstad OG, Hoff KA, Falck da Silva E, Svendsen HF (2012).Marine biodegradability and ecotoxicity of solvents for CO2-capture of natural gas.International Journal of Greenhouse Gas Control 9: 184-192.