(2-hydroxypropyl)trimethylammonium 2-ethylhexanoate

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:

weight of evidence

Study period:

2001

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Data from reliable source (NITE (National Institute of Technology and Evaluation) Japan). No test report is available however dat from this source are known to be well documented and the test are performed according to GLP and OECD guidelines.

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Alga, Growth Inhibition Test)

Deviations:

not specified

GLP compliance:

not specified

Analytical monitoring:

yes

Vehicle:

not specified

Test organisms (species):

Raphidocelis subcapitata (previous names: Pseudokirchneriella subcapitata, Selenastrum capricornutum)

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

96 h

Reference substance (positive control):

not specified

Key result

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

500 mg/L

Nominal / measured:

meas. (not specified)

Conc. based on:

test mat.

Basis for effect:

growth rate

Validity criteria fulfilled:

not specified

Conclusions:

An OECD 201 static test using Pseudokirchneriella subcapitata derived a 72 hour EC50 of 500 mg/L

Reference 2

Endpoint:

toxicity to aquatic algae and cyanobacteria

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

2017-2018

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Alga, Growth Inhibition Test)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

Identification: Hydroxypropyl, 2-, trimethylammonium formate
Physical state/Appearance: Colorless to very light blue liquid
Batch: Chernil.20160628.B
CAS#: 62314-25-4
Purity: 92.25% active in water
Expiry Date: 28 June 2017
Storage Conditions: Room temperature in the dark from 24 October 2016 to
08 November 2016, thereafter, room temperature in the
dark over silica gel

Analytical monitoring:

yes

Details on sampling:

Samples of the algal populations were removed daily and cell concentrations determined for each control and treatment group, using a Coulter® Multisizer Particle Counter.

Vehicle:

no

Details on test solutions:

A 1.0 mg/L test solution was prepared from which two samples were taken, one sample was taken for 0-Hour analysis (stored frozen), the other sample was incubated under test conditions for 72 hours prior to analysis. A further aliquot of the initial 1.0 mg/L test
solution was inoculated with algal suspension (nominal cell density 5.00 x 103 cells/mL) from which two samples were taken, one sample was taken for 0-Hour analysis (stored frozen), the other sample was incubated under test conditions for 72 hours prior to analysis. After 72 hours all samples were removed from the incubator and freezer and sent for analysis.

Test organisms (species):

Raphidocelis subcapitata (previous names: Pseudokirchneriella subcapitata, Selenastrum capricornutum)

Details on test organisms:

The test was carried out using Pseudokirchneriella subcapitata strain CCAP 278/4. Liquid cultures of Pseudokirchneriella subcapitata were obtained from the Culture Collection of Algae and Protozoa (CCAP), SAMS Research Services Ltd, Scottish Marine Institute, Oban, Argyll, Scotland. Master cultures were maintained in the laboratory by the periodic replenishment of culture medium (Section 3.3). The master cultures were maintained in the laboratory under constant aeration and illumination at 21 ± 2 °C.

Test type:

flow-through

Water media type:

freshwater

Limit test:

no

Total exposure duration:

72 h

pH:

7.2 at 0h
7.6 at 72h

Nominal and measured concentrations:

Analysis of the test preparations at 0 and 72 hours showed measured test concentrations to be near nominal with the exception of the 1.0 mg/L test preparations which showed a measured test concentration of 1.8 mg/L at both 0 and 72 hours.

Reference substance (positive control):

yes

Key result

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Results with reference substance (positive control):

The results from the positive control with potassium dichromate were within the normal ranges for this reference item.

Validity criteria fulfilled:

yes

Conclusions:

The effect of the test item on the growth of Pseudokirchneriella subcapitata has been investigated over a 72-Hour period and gave aGrowth Rate EC50 of >100mg/L, a NOEC of 3.2 mg/L and a LOEC of 10 mg/L
It was not possible to calculate an ErC50 value as no concentration tested resulted in 50% inhibition of growth rate.

Description of key information

The effect of the read-across substance TMR2 (Hydroxypropyl, 2-, trimethylammonium formate) on the growth of Pseudokirchneriella subcapitata has been investigated over a 72-Hour period in an OECD 201 static test and gave aGrowth Rate EC50 of >100mg/L, a NOEC of 3.2 mg/L and a LOEC of 10 mg/L

It was not possible to calculate an ErC50 value as no concentration tested resulted in 50% inhibition of growth rate.

An OECD 201 static test in Pseudokirchneriella subcapitata using the dissociation product 2-ethylhexanoic acid derived a 72 hour EC50 of 500 mg/L

On this basis the lowest EC50 value of of 100 mg/L. is assigned to TMR (2-hydroxypropyl)trimethylammonium 2-ethylhexanoate)

Key value for chemical safety assessment

EC50 for freshwater algae:

100 mg/L