3-aminopropane-1,2-diol

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:

2014

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Freshwater Alga and Cyanobacteria, Growth Inhibition Test)

Version / remarks:

2006

Qualifier:

according to guideline

Guideline:

EU Method C.3 (Algal Inhibition test)

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

- Physical state: liquid
- Water solubility: >100 g/L

Details on sampling:

The test substance (nominally 100 mg) was dissolved (by shaking) in dilution medium in a volumetric flask (1 L) to provide a stock solution without pH adjustment at a nominal concentration of 100 mg/L. This stock was serially diluted with dilution medium using aliquots (312 or 313 mL) in volumetric flasks (1 L) to provide test media with no pH adjustment at nominal concentrations of 31.3, 9.77, 3.05 or 0.954 mg/L.

A second set of media were prepared at nominal concentrations of 31.3 and 100 mg/L as indicated above but with adjustment of the pH of the stock solution at nominal 100 mg/L to pH 7.5 using 1M hydrochloric acid (HCl) and 0.1 M sodium hydroxide (NaOH) as appropriate. An aliquot (313 mL) of this adjusted stock solution was diluted (to 1 L) to provide test medium with a nominal concentration of 31.3 mg/L.

An aliquot (4.2 mL) of the secondary algal inoculum was added to a portion (400 mL) of the test medium at each concentration, to give an initial cell density of ca. 1 x 104 cells/mL. The control cultures were prepared as for the test medium except that no test substance was added and a larger volume (700 mL) of medium was made. An aliquot (100 mL) of the appropriate inoculated control or test medium was added to each of the test vessels.

Vehicle:

no

Test organisms (species):

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

Details on test organisms:

TEST ORGANISM
- Strain: CCAP 278/4
- Source (laboratory, culture collection): SAMS Research Services Ltd., Dunstaffnage Marine Laboratory, Dunbeg, Oban, Argyll, Scotland
- Method of cultivation:
The liquid slope cultures were stored in an illuminated refrigerator. Sterile algal nutrient medium was inoculated with cells aseptically removed from the slope culture; these primary liquid cultures (100 mL) were incubated for approximately three days in an orbital incubator under continuous illumination at nominal temperatures in the range 21 to 25C. Subsequently, appropriate volumes of these primary cultures were aseptically transferred to fresh sterile algal nutrient medium to prepare secondary liquid cultures; these cultures were incubated, as stated above, for a further three days to provide an inoculum in the log phase of growth, characterised by a cell density of 9.6 x 105 cells/mL.

Water media type:

freshwater

Total exposure duration:

72 h

Hardness:

No data

Test temperature:

22.7 - 23.1 deg C

pH:

7.62 - 9.58

Dissolved oxygen:

No data

Salinity:

No data

Conductivity:

No data

Nominal and measured concentrations:

Based on the results of the range finding test, the definitive test selected concentrations of 0.954, 3.05, 9.77, 31.3 and 100 mg/L as APD, with non-adjusted media for pH, plus an additional two groups at 31.3 and 100 mg/L as APD, with adjustment for pH.

Reference substance (positive control):

yes

Remarks:

potassium dichromate

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Basis for effect:

growth rate

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Basis for effect:

growth rate

Remarks on result:

other: pH adjusted

Validity criteria fulfilled:

yes

Conclusions:

Based on the OECD 201, the 72-hours EbC50, ErC50 and EyC50 values were greater than 100 mg/L (nominal). The ‘no-observed effect concentration’ (NOEC) was 31.3 mg/L without pH adjustment and 100 mg/L with pH adjustment. The results suggest that the pH of the medium was primarily responsible for the inhibition (between 3 and 18%) observed at 100 mg/L.

Description of key information

Based on OECD 201, the E_bC₅₀, E_rC₅₀ and E_yC₅₀ values are greater than 100 mg/L. The "No-Observed Effect Concentration" (NOEC) is >100 mg/L with pH adjustment.

Key value for chemical safety assessment

EC50 for freshwater algae:

100 mg/L

EC10 or NOEC for freshwater algae:

100 mg/L