Dimethylamine

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:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Experimental determination according to national guideline, no information about GLP

Qualifier:

according to guideline

Guideline:

other: EPA, National Eutrophication Research Program, Corvallis, Oreg. (1971)

Principles of method if other than guideline:

Algal assay with Selenastrum capricornutum, in order to determine the 96h EC50 (effective concentration inhibiting the growth for 50 % of the population at 96h).

GLP compliance:

not specified

Analytical monitoring:

not specified

Vehicle:

no

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

Hardness:

320 mg CaCO3/L

Test temperature:

15 °C

pH:

7.4

Dissolved oxygen:

more than 95 % saturation

Reference substance (positive control):

not specified

Duration:

96 h

Dose descriptor:

EC0

Effect conc.:

2 mg/L

Nominal / measured:

not specified

Conc. based on:

act. ingr.

Basis for effect:

growth rate

Duration:

96 h

Dose descriptor:

EC50

Effect conc.:

9 mg/L

Nominal / measured:

not specified

Conc. based on:

act. ingr.

Basis for effect:

growth rate

Duration:

96 h

Dose descriptor:

EC100

Effect conc.:

40 mg/L

Nominal / measured:

not specified

Conc. based on:

act. ingr.

Basis for effect:

growth rate

Validity criteria fulfilled:

yes

Conclusions:

EC0 (96h) = 2 mg/L
EC50 (96h) = 9 mg/L
EC100 (96h) = 40 mg/L

Executive summary:

Calamari D. et.al. (1980) performed an experiment according to EPA, National Eutrophication Research Program, Corvallis, Oreg. (1971) to test the acute toxicity of dimethylamine (and other amines) to Selenastrum capricornutum (new name: Pseudokirchnerella subcapitata). Reported results are EC0 (96h) = 2 mg/L, EC50 (96h) = 9 mg/L, and EC100 (96h) = 40 mg/L, respectively.

Reference 2

Endpoint:

toxicity to aquatic algae and cyanobacteria

Remarks:

Marine phytoplankton test (ISO guideline 10253) with Skeletonema costatum

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study without detailed documentation

Reason / purpose for cross-reference:

reference to same study

Qualifier:

according to guideline

Guideline:

ISO 10253 (Water quality - Marine Algal Growth Inhibition Test with Skeletonema costatum and Phaeodactylum tricornutum)

Version / remarks:

Version of 1999

Deviations:

no

Principles of method if other than guideline:

The guideline used is a standardized test for assessing the ecotoxicity in the marine environment, based on the Convention for the Protection of the Marine Environment of the North-East Atlantic (OSPAR Convention). The Norwegian Activities Regulation (PSA, 2010) states minimum recommended EC50/LC50 values of ≥10 mg/L in acute ecotoxicity.

GLP compliance:

not specified

Analytical monitoring:

no

Details on sampling:

- Concentrations: The choice of test concentrations was based on a preliminary test with ten-fold dilutions of the test substance (10–10,000 mg/L).
- Sampling method: As described in guideline ISO 10253.
- Sample storage conditions before analysis: No details available.

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances) :
- Method: Concentration series of each chemical was prepared in triplicate in a seawater-based algal culture medium, and the algal in exponential growth phase was inoculated in each test solution at algal concentrations of approximately 3×10E3 cells/mL.
- Eluate: Not required.
- Differential loading: Not required.
- Controls: As controls, algae were also inoculated to algal culture medium without test substance.
- Chemical name of vehicle (organic solvent, emulsifier or dispersant): No vehicle used.
- Concentration of vehicle in test medium (stock solution and final test solution(s) or suspension(s) including control(s)): Not applicable.
- Evidence of undissolved material (e.g. precipitate, surface film, etc.): No.

For the ecotoxicity test, small differences in the initial densities of algae might have a large impact, as the algal growth is exponential.

Test organisms (species):

Skeletonema costatum

Details on test organisms:

TEST ORGANISM
- Common name: Skeletonema costatum
- Strain: Not specified
- Source (laboratory, culture collection): Source of phytoplankton not specified.
- Age of inoculum (at test initiation): Algae in exponential growth phase were inoculated in each test solution. Algal concentrations: approximately 3×10E3 cells/mL.
- Method of cultivation: Cultivation in seawater-based culture medium.

ACCLIMATION
- Acclimation period: No details reported.
- Culturing media and conditions (same as test or not): No details reported.
- Any deformed or abnormal cells observed: No deformed or abnormal cells observed.

Test type:

static

Water media type:

saltwater

Remarks:

The seawater used in the biodegradability tests may differ somewhat for each experiment, as it is not synthetic and the transport time and storage in the reservoir could vary.

Limit test:

no

Total exposure duration:

72 h

Post exposure observation period:

No post-exposure observations performed.

Hardness:

Natural seawater was used.

Test temperature:

20°C± 2°C

pH:

pH value not reported. Natural seawater was used.

Dissolved oxygen:

Dissolved oxygen content not reported. Natural seawater was used.

Salinity:

Salinity value not reported. Natural seawater was used.

Conductivity:

Natural seawater was used.

Nominal and measured concentrations:

The choice of test concentrations was based on a preliminary test with ten-fold dilutions of the test substance (10–10,000 mg/L).

Details on test conditions:

TEST SYSTEM
- Test vessel: Test tubes, according to guideline ISO 10253.
- Type (delete if not applicable): open
- Material, size, headspace, fill volume: No details reported.
- Aeration: No, but agitation was performed during incubation.
- Type of flow-through (e.g. peristaltic or proportional diluter): No flow-through conditions implemented in this study.
- Renewal rate of test solution (frequency/flow rate): Not applicable.
- Initial cells density: Initial algal concentration was approximately 3×10E3 cells/mL.
- Control end cells density: Not reported.
- No. of organisms per vessel: Initial algal concentration was approximately 3×10E3 cells/mL.
- No. of vessels per concentration (replicates): Concentration series for each chemical was prepared in triplicate.
- No. of vessels per control (replicates): Not specified, test design according to guideline ISO 10253.
- No. of vessels per vehicle control (replicates): No vehicle used.

GROWTH MEDIUM
- Standard medium used: yes
- Detailed composition if non-standard medium was used: Not applicable.

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Culture medium was based on natural seawater.
- Total organic carbon: Information not available.
- Particulate matter: Information not available.
- Metals: Information not available.
- Pesticides: Information not available.
- Chlorine: Information not available.
- Alkalinity: Information not available.
- Ca/Mg ratio: Information not available.
- Conductivity: Information not available.
- Culture medium different from test medium: No.
- Intervals of water quality measurement: Daily.

OTHER TEST CONDITIONS
- Sterile test conditions: no
- Adjustment of pH: No.
- Photoperiod: Not reported. Constant light intensity was applied.
- Light intensity and quality: Constant light intensity of 60-120 µE/s/m².
- Salinity (for marine algae): No details reported. Natural seawater served as base of culture medium.

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :
- Determination of cell concentrations: [counting chamber; electronic particle counter; fluorimeter; spectrophotometer; colorimeter]: Information not available.
- Chlorophyll measurement: In vivo chlorophyll fluorescence was measured daily in a filter fluorometer (model TD-700, Turner Designs, Sunnyvale, CA, USA)

TEST CONCENTRATIONS
- Spacing factor for test concentrations: Information not available.
- Justification for using less concentrations than requested by guideline:
- Range finding study: The choice of test concentrations was based on a preliminary test with ten-fold dilutions of the test substance (10–10,000 mg/L).
- Test concentrations: Specific concentration levels for DMA not reported.
- Results used to determine the conditions for the definitive study: Yes, observed toxicity range was taken into account for selection of final test substance concentrations.

Reference substance (positive control):

no

Remarks:

42 amines and one organosulfuric compound were tested

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

28 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other: 95% confidence interval: EC50 = 26-31 mg/L

Details on results:

- Exponential growth in the control (for algal test): Yes
- Observation of abnormalities (for algal test): Not observed.
- Unusual cell shape: Not observed.
- Colour differences: Not observed.
- Flocculation: Not observed.
- Adherence to test vessels: Not observed.
- Aggregation of algal cells: Not observed.
- Any stimulation of growth found in any treatment: No stimulation of growth found.
- Any observations (e.g. precipitation) that might cause a difference between measured and nominal values: No precipitation observed. For the ecotoxicity test, small differences in the initial densities of algae might have a large impact, as the algal growth is exponential.
- Effect concentrations exceeding solubility of substance in test medium: No.

Results with reference substance (positive control):

No reference substance (positive control) investigated in this study.

Reported statistics and error estimates:

Growth rates of algae were calculated by linear regression analyses of the logarithmic of algal growth curves as well as the area under the growth curves (biomass) for each concentration of chemical and for controls. The effective concentrations (mg/L) of test substance inhibiting algal growth by 50% (EC50), relative to the control cultures, were calculated with a 95% confidence interval using the ecotoxicity calculation program TOXEDO (Water Quality Institute, Hørsholm, Denmark).

The aquatic toxicity results for the 43 amine compounds show a wide variability, with Skeletonema EC-50 ranging from 1.84 to >10,000 mg/L (median 198 mg/L). Most of the compounds tested had an EC50 above 10 mg/L, and as such the toxicity is not a problem for use of the chemicals.

For DMA (CAS 124 -40 -3) a EC50 value of 28 mg/L was calculated.

Validity criteria fulfilled:

yes

Conclusions:

In a screening study with marine phytoplankton species Skeletonema costatum aquatic toxicity of dimethylamine (DMA, CAS 124-40-3) and further 42 amines was determined. The test was performed according to ISO guideline 10253 of 1999. For DMA a EC50 (72 h) value of 28 mg/L was calculated.

Executive summary:

Anthropogenic CO₂emissions are considered to be one of the main sources of today’s global warming (IPCC, 2007). Carbon capture and storage (CCS) is one of the technologies that can be used to mitigate climate change, and among the capture technologies, reactive absorption is considered the most feasible, in particular for post combustion capture. Most relevant amines for CO2-capture are alkanolamines.

Beside dimethylamine (CAS 124 -40 -3), 42 further chemicals were tested in this study, including 41 amines (alkanolamines, polyamines, cyclic amines, amino acids, volatile amines) and one organosulfuric compound. The test chemicals were obtained commercially with a purity of >95%.

The ecotoxicity was determined by a marine phytoplankton test, conducted according to ISO/DIS guideline 10253, using the algal speciesSkeletonema costatum (ISO, 1999). Concentration series of each chemical was prepared in triplicate in a seawater-based algal culture medium, and the algal in exponential growth phase was inoculated in each test solution at algal concentrations of approximately 3×10E3 cells/mL. The choice of test concentrations was based on a preliminary test with ten-fold dilutions of the test substance (10–10,000 mg/L). As controls, algae were also inoculated to algal culture medium without test substance. All test tubes were incubated with agitation under constant light intensity (60–120 µE/s/m2) and a temperature of 20 ± 2°C for 72 h. In vivo chlorophyll fluorescence was measured daily in a filter fluorometer (model TD-700, Turner Designs, Sunnyvale, CA, USA).

Growth rates were calculated by linear regression analyses of the logarithmic of algal growth curves as well as the area under the growth curves (biomass) for each concentration of chemical and for controls. From these parameters the effective concentrations (mg/L) of test substance inhibiting algal growth by 50% (EC50), relative to the control cultures, were calculated with a 95% confidence interval using the ecotoxicity calculation program TOXEDO (Water Quality Institute, Hørsholm, Denmark).

Results: The results show a wide variability, with Skeletonema EC50 ranging from 1.84 to >10,000 mg/L (median 198 mg/L). Most of the compounds tested had low acute toxicity, with only five compounds having EC-50-values below 10 mg/L. Most of the compounds tested had an EC-50 above 10 mg/L, and as such the toxicity is not a problem for use of the chemicals (trigger criterion of Norwegian Activities Regulation; PSA, 2010). For dimethylamine (DMA, CAS 124-40-3) an EC50 (72 h) value of 28 mg/L was calculated.

Reference 3

Endpoint:

toxicity to aquatic algae and cyanobacteria

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Short documentation. However, from reliable source. No analytical verification of test concentration. Unsuitable test system: non-standard exposure period (7d)

Qualifier:

according to guideline

Guideline:

other: LTwS No. 10 (Lagerung und Transport wassergefährdender Stoffe; Storage and transport of substances hazardous to water), UBA Germany

Principles of method if other than guideline:

7-d static exposure of green algae (Desmodesmus subspicatus) to test solutions

GLP compliance:

not specified

Specific details on test material used for the study:

Details on properties of test surrogate or analogue material: No surrogate or analogue material was used.

Analytical monitoring:

no

Details on sampling:

No details available.

Vehicle:

not specified

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
- Method: test solutions are neutralised if pH shift is significant

Test organisms (species):

Desmodesmus subspicatus (previous name: Scenedesmus subspicatus)

Details on test organisms:

TEST ORGANISM
- Common name: green algae
- Source: laboratory culture
- Age of inoculum (at test initiation): 7 d
- Method of cultivation: stock culture kept under sterile conditions

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

7 d

Post exposure observation period:

No post exposure observation period reported.

Hardness:

No details available.

Test temperature:

27 °C

pH:

No details available.

Dissolved oxygen:

No details available.

Salinity:

Not applicable.

Nominal and measured concentrations:

No details available.

Details on test conditions:

TEST SYSTEM
- Type: open
- Material, size, headspace, fill volume: glass, 300-mL Erlenmeyer flasks, fill volume: 50 mL
- Aeration: none
- Initial cells density: standardised tubidity (TE/F/578 nm = 20)
- No. of vessels per concentration (replicates): 3
- No. of vessels per control (replicates): 3
- Other: shaken once per day

GROWTH MEDIUM
- Standard medium used: no

OTHER TEST CONDITIONS
- Sterile test conditions: no
- Adjustment of pH: yes
- Photoperiod: continuous illumination

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :
- Determination of cell concentrations: turbidity

Reference substance (positive control):

not specified

Duration:

7 d

Dose descriptor:

other: EC3

Effect conc.:

2.6 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: turbidity

Remarks on result:

other: neutralised

Details on results:

No details available.

Results with reference substance (positive control):

Not applicable.

Reported statistics and error estimates:

No details available.

Validity criteria fulfilled:

not specified

Remarks:

Basic data available.

Conclusions:

No detailed study description available. EC3(7d): 2.6 mg/L for Scenedesmus subspicatus.

Executive summary:

The green algae Desmodesmus subspicatus was exposed for 7 days to the test substance in accordance to the national guideline LTwS No. 10 (Trenel and Kuhn, 1982). Continuous illumination was applied during the static freshwater test. The test vessels were shaken once per day. The turbidity was used as basis of effect, whereby giving an EC3 value of 2.6 mg/L at the end of the test.

Description of key information

Selenastrum capricornutum (new name: Pseudokirchnerella subcapitata): EC0 (96h): 2 mg/L (corresponding to NOEC), EC50 (96h): 9 mg/L, EC100 (96h): 40 mg/L (Calamari et al., 1980),
Desmodesmus subspicatus: EC3 (7d): 2.6 mg/L (Trenel and Kuhn, 1982),
Chlorella pyrenoidosa: EC50 (96h): 30 mg/L (Van Leeuwen et al., 1985; cited in HSDB, 2010),

Marine algae species Skeletonema costatum: EC50 (72h): 28 mg/L (Eide-Haugmo et al., 2012)

Key value for chemical safety assessment

EC50 for freshwater algae:

9 mg/L

EC50 for marine water algae:

28 mg/L

EC10 or NOEC for freshwater algae:

2 mg/L

Additional information

Calamari et al. (1980) performed an experiment according to EPA, National Eutrophication Research Program, Corvallis, Oreg. (1971) to test the acute toxicity of dimethylamine (and other amines) to Selenastrum capricornutum (new name: Pseudokirchnerella subcapitata). Reported results are EC0 (96h): 2 mg/L (i.e. NOEC), EC50 (96h): 9 mg/L, and EC100(96h): 40 mg/L, respectively. This EC50 value for the algae species is also cited in the peer-reviewed database HSDB (2010). The green algae Desmodesmus subspicatus was exposed for 7 days to the test substance in accordance to the national guideline LTwS No. 10 (Trenel and Kuhn, 1982). Continuous illumination was applied during the static freshwater test. The test vessels were shaken once per day. The turbidity was used as basis of effect, whereby giving an EC3 value of 2.6 mg/L at the end of the test.

The freshwater algae Chlorella pyrenoidosa was exposed to the test substance for 96 h in a static experiment (Van Leeuwen et al., 1985). No reference guideline is mentioned. 200 mL Erlenmeyerflasks were taken as test vessels and placed on a mechanical shaker with an initial cell density 10E8 cells/mL. The temperature was held constant at 20 +/- 1 °C and continuous illumination was applied. 3 replicates per concentration and control was applied, however, no test concentrations are available. The EC50 value was reported as 30 mg/L. This value is also cited in the peer-reviewed database HSDB (2010).

The freshwater algae Scenedesmus quadricauda was used in a static experiment to investigate the toxicity of the test substance (Chromek, Kupec and Mladek, 1983). The substance concentration in the algal biomass was determined in aqueous filtrate from disintegrated and washed cells using gas chromatography. The nominal test concentrations were 0, 150 and 300 mg/L. An addition of 150 mg/L test substance showed no effect on the biomass production rate. 300 mg/L induced a substantial growth-rate reduction in the approx. linear portion of the algal growth curve. Since the exposure period was about 150 hours, the test system has to be considered as unsuitable, since this period last longer than the phase of exponential algal growth.

In a static screening study of Eide-Haugmo et al. (2012) with marine phytoplankton species Skeletonema costatum aquatic toxicity of dimethylamine (DMA, CAS 124-40-3) and further 42 amines was determined. The test was performed according to ISO guideline 10253 of 1999, natural seawater served as test medium. Test substance concentrations used in this study were based on pre-tests with wide concentration-ranges. For DMA a EC50 (72 h) value of 28 mg/L was calculated.