N'-[3-(dimethylamino)propyl]-N,N-dimethylpropane-1,3-diamine

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:

2012-02-27 - 2012-03-02

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

other: German Industrial Standard DIN 38412 part 15

Deviations:

no

GLP compliance:

yes

Specific details on test material used for the study:

- Name of test material (as cited in study report): Bis-DMAPA
- Physical state: liquid
- Supplier: SGS Belgium N.V.
- Batch number: PFW110019
- Purity: 97.8%
- Purity test date: May 30th 2011
- Total amine content: 16.02 meq/g
- Storage condition of test material: lab storage

Analytical monitoring:

yes

Details on sampling:

- Samples for test substance analysis were taken at 0 and 72 h (at 0 h from excess test solutions and at 72 h from a single replicate of each exposure solution (containing algae))
- Sampling method: no data
- Sample storage conditions before analysis: no data

Vehicle:

no

Details on test solutions:

- 120 mg/L stock solution (0.12 g in 1000 mL culture medium) stirred for 15 min
- Lower test concentrations prepared by serial dilution using the primary stock solution and stirring for 10 min

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): in-house cultures kept under axenic conditions
- Age of inoculum (at test initiation): 3 days (in exponential growth phase)

ACCLIMATION
- Acclimation period: none
- Culturing media and conditions (same as test or not): same as test
- Any deformed or abnormal cells observed: not noted

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

72 h

Post exposure observation period:

none

Hardness:

15 mg CaCO3/L (calculated based on medium composition)

Test temperature:

22 +/- 2 degrees C

pH:

Start of test: 6.1-8.4
End of test: 7.5-7.8

Dissolved oxygen:

N/A

Salinity:

N/A

Nominal and measured concentrations:

Nominal concentrations: 0, 0.11, 0.36, 1.2, 3.7, 12, 38, 120 mg/L
Overall mean measured concentrations were 98-103% of nominal values.

Details on test conditions:

TEST SYSTEM
- Test vessel: glass conical flask
- Test vessels covered or not: closed with foam bungs
- Material, size, headspace, fill volume: glass, 250 mL, 100 mL fill volume
- Aeration: only by nominal orbital shaking at 160 rpm
- Initial cells density: 0.5 x10^4
- Control end cells density: 103 times initial density
- No. of vessels per concentration (replicates): 3
- No. of vessels per control (replicates): 6
- One blank vessel (without algal inoculum) was incubated for each test concentration and the culture medium control (for background corrections)
- Random position in incubator, changed daily

GROWTH MEDIUM
- Standard medium used: yes (AAP medium)

TEST MEDIUM / WATER PARAMETERS
- Culture medium different from test medium: no

OTHER TEST CONDITIONS
- Sterile test conditions: yes
- Adjustment of pH: with 1M HCl to appropriate range
- Photoperiod: 24 h light
- Light intensity and quality: cool-white, 6173 lux, +/-4%

EFFECT PARAMETERS MEASURED (with observation intervals if applicable): algal cell density (calculated parameters: biomass and growth rate) was determined after 24, 48 and 72 h
- Determination of cell concentrations: Coulter electronic particle counter

TEST CONCENTRATIONS
- Spacing factor for test concentrations: 3.1-3.3

Key result

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

1.2 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Key result

Duration:

72 h

Dose descriptor:

EC10

Effect conc.:

1.7 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other: 95% CI = 1.2-2.2

Key result

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

7.9 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other: 95% CI = 7.1-8.8

Details on results:

- Exponential growth in the control (for algal test): yes
- Observation of abnormalities (for algal test): none observed
- Effect concentrations exceeding solubility of substance in test medium: none
Biomass based effect concentrations:
- EbC10 = 0.57 mg/L (95% CI = 0.36-1.7 mg/L)
- EbC20 = 1.0 mg/L (95% CI = 0.6-1.8 mg/L)
- EbC50 = 2.5 mg/L (95% CI = 2.0-2.9 mg/L)
- NOEC = 0.36 mg/L
- LOEC = 1.2 mg/L
Remaining growth rate based effect concentrations:
- EbC20 = 2.8 mg/L (95% CI = 2.5-3.2 mg/L)
- LOEC = 3.7 mg/L

Reported statistics and error estimates:

NOEC and LOEC values were determined by one-way analysis of variance and Dunnett's procedure to identify significant differences (p<0.05) between individual treatments and the culture medium control.
EC50, EC20 and EC10 values and their associated confidence intervals were calculated using the Linear Interpolation method.

Validity criteria fulfilled:

yes

Conclusions:

In this study, performed according to the standard DIN 38412-15 (similar to the OECD guideline 201), the growth rate based 72-h EC50 of the test substance for the freshwater alga Pseudokirchneriella subcapitata was found to be 7.9 mg/L. The growth rate based 72-h NOEC was determined to be 1.2 mg/L. Analytical verification of test substance concentrations indicated that measured concentrations were always close to nominal concentrations. The results of this well performed study can be considered reliable.

Description of key information

One study (Hayfield and Rice, 2012) investigating the toxicity of the substance to algae according to the German Industrial Standard Test Guideline DIN 38412, was considered as the key study for endpoint coverage. The 72h-ErC50 and 72h-NOEC were determined to be 7.9 and 1.2 mg test material/L respectively (based on nominal concentration). The study is given a Klimisch score of 1 and was conducted under GLP.

Key value for chemical safety assessment

EC50 for freshwater algae:

7.9 mg/L

EC10 or NOEC for freshwater algae:

1.2 mg/L