Amines, di-C12-18-alkylmethyl

Toxicity to aquatic algae and cyanobacteria

Link to relevant study record(s)

Reference

Endpoint:

toxicity to aquatic algae and cyanobacteria

Type of information:

experimental study

Adequacy of study:

key study

Study period:

from 2008-02-11 to 2008-06

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)

Analytical monitoring:

yes

Details on sampling:

no data

Vehicle:

no

Details on test solutions:

Since the substance is not soluble in water, Water Accomodated Fractions (WAF) approach has been followed.
WAFs are prepared by adding carefully measured amounts of the substance directly to water and by mixing for 72 h to achieve an equilibrated concentration of the components in the aqueous phase. After mixing, solutions were filtered to obtain limpid solutions. No water-miscible solvents were used. Care is taken to avoid the formation of emulsions.
Excepted for the lower loading rates, WAFs are prepared individually and not by serial dilution of a single stock WAF. Measured amounts of multi-component substances are added.

Test organisms (species):

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

Details on test organisms:

TEST ORGANISM
- Strain: CCAP 278/4
- Source: Culture Centre of Algae and Protozoa (Ambleside, UK)

ACCLIMATION
Culturing media and conditions:
Two flasks, each containing approximately 100 mL of axenic stock culture of algae are incubated at 23 ± 1 °C under lighting (photoperiod: 16 hours of illumination, 8 hours of darkness), slowly continuously shaken. These stock cultures are renewed every week, using two new cultures.
The quality of the stock culture was verified for the absence of micro-organisms and deformed cells under microscopic observation before use.
Three days before the beginning of the study two pre-cultures were prepared by inoculating each stock suspension of algae (5 mL) into sterile dilution water (500 mL). The pre-cultures were incubated under the same conditions as those used for the stock cultures. Only one of the two pre-cultures was used to inoculate the test flasks; the second one was to be used only if the first one was damaged.
At the beginning of the test, the cell concentration of the pre-culture was determined. The result was used to calculate the volume to be introduced into each test flask in order to get an initial cell concentration of 104 cells/mL.
The cell density of the pre-culture was about 6.587 x 106 cells/mL.

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

72 h

Hardness:

no data

Test temperature:

23 ± 1 °C

pH:

7.82 - 9.97

Dissolved oxygen:

8.2 - 10.5 mg O2/L

Salinity:

no data

Nominal and measured concentrations:

Nominal concentrations: 0.01 - 0.05 - 0.1 - 0.5 and 1 mg/L
All measured concentrations were found to be below the detection limit of the analytical method (0.73 µg/L).

Details on test conditions:

TEST SYSTEM
- Test vessel: 120 mL glass bottles stoppered with cellulose bungs
- Filling volume: 50 mL
- Incubation performed in a phytoculture cabinet
- Triplicates in each treatment and 6 replicates for the control group

OTHER TEST CONDITIONS
- Illumination: constantly illuminated by 8 fluorescent tubes between 6,000 and 10,000 lux
- Continuously shaken with a rotation at 20 rpm

Reference substance (positive control):

yes

Remarks:

Potassium dichromate

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

0.26 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

biomass

Remarks on result:

other: 95% CL = 0.08-4.7 mg/L

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

0.7 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Details on results:

Solutions were found to be clear, colourless over the period of the test. No precipitation was observed at the end of the test.
Microscopic observation confirmed that the algae appeared normal at the end of the test.

Results with reference substance (positive control):

Sodium dichromate: ErC50: 0.60 to 1.03 mg/L EbC50: 0.20 to 0.75 mg/L

Validity criteria fulfilled:

yes

Remarks:

see conclusions

Conclusions:

Validity criteria were fulfilled:
- The biomass in the control cultures has increased exponentially by a factor higher than 16 within the 72-hour test period. This corresponds to a specific growth rate of 0.92 day-1.
- The mean coefficient of variation for section-by-section specific growth rates (days 0-1, 1-2 and 2-3, for 72-hour tests) in the control cultures did not exceed 35%. This criterion applies to the mean value of coefficients of variation calculated for replicate control cultures.
- The coefficient of variation of average specific growth rates during the whole test period in replicate control cultures did not exceed 7%.

Executive summary:

Acute toxicity of dicocomethylamine to Pseudokirchnerella subcapitata has been examinated through OECD Guideline 201 and GLP requirements.

Pseudokirchnerella subcapitata were exposed for 72 hours to an aqueous solution of dicocomethylamine

at nominal concentrations of 0.01 - 0.05 - 0.1 - 0.5 and 1 mg/L.

ErC 50 - 72h, based on growth rate, was determined to be of 0.7 mg/L, and EbC 50 - 72h, based on biomass, was determibed to be of 0.26 mg/L.

Description of key information

Based on a study according to OECD 201 guidelines EC50 for algae is 0.7 mg/L. 

A further algae study with Amines, C12-18-alkylmethyl is recently performed and the proposed draft report is planned to receive at the end of February 2023. The final report is expected to be available at the end of March 2023. 
This information will be submitted a little bit later based on ECHA communication/decision number CCH-D-2114585933-34-01/F.

Key value for chemical safety assessment

EC50 for freshwater algae:

0.7 mg/L