2,2-bis(hydroxymethyl)propionic acid

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:

1993-08-30 - 1993-09-02

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Alga, Growth Inhibition Test)

Deviations:

no

GLP compliance:

yes

Specific details on test material used for the study:

- Name of the test material used in the study report: 2.2-bis(hydroxymethyl)propionic acid
- Batch no.: 63004-14

Analytical monitoring:

not specified

Details on sampling:

Not applicable

Vehicle:

no

Test organisms (species):

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

Details on test organisms:

Source (laboratory, culture collection): Inoculum taken from Toxicon's own culture, which originated from the Swedish Environmental Protection Agency, Stockholm, Sweden

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

72 h

Post exposure observation period:

Not reported.

Hardness:

Not applicable

Test temperature:

23.5 (start of exposure) to 25.0 ºC (after 72 hours exposure).

pH:

pH in the nominal 1000 mg/L treatment was 3.5, the pH was therefore adjusted to 8.3 ± 0.2, adjusted with 1M NaOH. The initial pH in the control was 8.1, in the 100 mg/L treatment 8.4 and the 1000 mg/L 8.3, at the end of the 72 hour exposure period the pH values were 8.8 (control), 9.1 (100 mg/L) and 7.9 mg/L (1000 mg/L.)

Dissolved oxygen:

Not applicable

Salinity:

Not applicable

Nominal and measured concentrations:

0, 100, and 1000 mg/L.

Details on test conditions:

TEST SYSTEM
- Test vessels: 250 mL glass E-bottles with 100 mL solution
- No. of vessels per concentration (replicates): 3
- No. of vessels per control (replicates): 5

GROWTH MEDIUM
- Standard medium used: not specified
- Detailed composition if non-standard medium was used: refer to further details on methods.


OTHER TEST CONDITIONS
- Adjustment of pH: because of low pH, test solutions were adjusted with 1M NaOH solution to 8.3 ± 0.2.
- Photoperiod: continuous illumination
- Light intensity and quality:100 µE/m2/s


EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : sampling at 0, 24, 48, and 72 hours
- Determination of cell concentrations: Fluorescence
- Chlorophyll measurement: Yes

Reference substance (positive control):

no

Key result

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

750 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Details on results:

EC50 was graphically determined to be 750 mg/L.

Results with reference substance (positive control):

Not applicable

Reported statistics and error estimates:

Graphical estimation of the EC50
Growth rate calculated as per the OECD guidelines

Algal growth rates and percentage growth rate inhibition relative to the control.

	Control	100 mg/L	1000 mg/L
Growth rate, µ	1.83	1.84	0.58
Percent inhibition	0	-0.7	68.4

Validity criteria fulfilled:

yes

Conclusions:

The 72 hour EC50 value of Bis-MPA on the growth rate of Raphidocelis subcapitata was calculated as 750 mg/L (based on nominal exposure concentrations).

Executive summary:

In a 72 hour acute toxicity study, the cultures of green alga Raphidocelis subcapitata were exposed to Bis-MPA at nominal concentrations of 0, 100 and 1000 mg/L under static conditions in accordance with the OECD 201 guideline. The EC₅₀ value based on growth rate was 750 mg/L.

 

This toxicity study is classified as acceptable and satisfies the guideline requirements for an acute algae toxicity study.

 

Results Synopsis

 

Test Organism: Raphidocelis subcapitata

Test Type: Static

 

72-hr EC₅₀:  750 mg/L

Endpoint(s) Effected:  Growth rate

 

 

Description of key information

A short-term toxicity test with algae (Raphidocelis subcapitata) resulted in an EC50 (growth rate) of 750 mg/L.

Key value for chemical safety assessment

EC50 for freshwater algae:

750 mg/L

Additional information

Adverse effects have been observed above the highest recommended concentration (100 mg/L). Accordingly, the substance is not hazardous in terms of the CLP Regulation.