Tributylamine

Short-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

Test period from 24 Feb 1998 to 26 Feb 1998

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Guideline study

Qualifier:

according to guideline

Guideline:

EPA OTS 797.1300 (Aquatic Invertebrate Acute Toxicity Test, Freshwater Daphnids)

Version / remarks:

(Edition 7-1-92)

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Qualifier:

according to guideline

Guideline:

ISO 6341 (Water quality - Determination of the Inhibition of the Mobility of Daphnia magna Straus (Cladocera, Crustacea))

Qualifier:

according to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

GLP compliance:

yes

Analytical monitoring:

yes

Details on sampling:

- Concentrations: 0 (control), 10, 40, and 160 mg/L
- Sampling method: Samples from the control and from three of the test concentrations were taken at the beginning of the test and after 24 hours, as well as at the beginning and end of the second exposure period (at 24 hours and 48 hours). 200 ml or 250 ml of test solution was transferred directly to a 200 ml, respectively a 250 ml measuring flask and spiked with 250 µl of a 100 ppm solution of aniline-d5 in methanol as an internal standard.
- Sample storage conditions before analysis: After separation of the organic phase, the samples were stored at 4ºC until transportation to the analyzing laboratory, DTI Kemiteknik

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: Test substance weighed into test medium establishing a stock solution; mixture was ultrasonicated for 5 min. followed by magnetic stirring for 22 hours. After separation of test medium and possible remaining particles or droplets for 2 hours, aliquots were sampled from the mid-fraction of the stock solution for preparation of the individual test concentrations.
- Controls: negative control
- Chemical name of vehicle (organic solvent, emulsifier or dispersant): none
- Concentration of vehicle in test medium (stock solution and final test solution): stock solution: 2000 mg/L
- Evidence of undissolved material (e.g. precipitate, surface film, etc): no

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: water flea
- Strain: Daphnia magna isolated from Lake Langedam, Birkeroed, Denmark in 1971
- Source: laboratory culture since 1971 at VKI
- Age at study initiation (mean and range, SD): < 24 h
- Feeding during test: no

ACCLIMATION
- Acclimation period: none

Test type:

semi-static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Hardness:

250±25 mg/L as CaCO3

Test temperature:

20±1 °C

pH:

7.9-8.0

Dissolved oxygen:

96-98 % saturation

Nominal and measured concentrations:

nominal/measured: 5.00/n.d., 10.0/1.27, 20.0/n.d., 40.0/3.52, 80.0/n.d., 160/20.0, 320/n.d. mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel:
- Type (delete if not applicable): closed
- Material, size, headspace, fill volume: glass vessel, 250 mL, 125 mL test solution
- Aeration: no
- Renewal rate of test solution (frequency/flow rate): semi-static (renewal after 24 h)
- No. of organisms per vessel: 5
- No. of vessels per concentration (replicates): 4
- No. of vessels per control (replicates): 6
- Biomass loading rate: 40 animals/L


TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: deionised water
- Culture medium different from test medium: yes


OTHER TEST CONDITIONS
- Adjustment of pH: no
- Photoperiod: 16/8 h light/darkness


EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :
- mobility and behaviour: 24 and 48 h

TEST CONCENTRATIONS
- Spacing factor for test concentrations: 2
- Range finding study: performed, but no data reported

Reference substance (positive control):

yes

Remarks:

potassium dichromate (K2Cr2O7)

Duration:

24 h

Dose descriptor:

EC50

Effect conc.:

19 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

act. ingr.

Basis for effect:

mobility

Remarks on result:

other: 95% CL: 8.7->40 mg/L

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

8 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

act. ingr.

Basis for effect:

mobility

Remarks on result:

other: 95% CL: 6.1-10.8 mg/L

Details on results:

- Behavioural abnormalities: not reported
- Mortality of control: 0 %
- Other adverse effects control: no
- Abnormal responses: no
- Any observations (e.g. precipitation) that might cause a difference between measured and nominal values: no
- Effect concentrations exceeding solubility of substance in test medium: no

Results with reference substance (positive control):

- Results with reference substance valid? yes
- EC50/LC50: 1.26 mg/L

Observations

Test item concentration [mg/L]	Total number of animals per concentration	Number of immobile animals after
		24 h	48 h
control	30	0	0
5.00	20	0	0
10.0	20	1	1
20.0	20	0	1
40.0	20	1	4
80.0	20	12	15
160	20	10	14
320	20	12	16

Chemical analysis

Nominal	Start 1	End 1	Mean 1	Start 2	End 2	Mean 2	Mean	Regression
0		0.012	0.012	0.005	0.008	0.0065	0.00925	-0.4231371
10	1.43	1.49	1.46	1.15	0.99	1.07	1.265	0.83921045
40	3.98	3.62	3.8	3.48	2.99	3.235	3.5175	4.62625307
160	23	20.2	21.6	19.1	17.8	18.45	20.025	19.7744236

Linear regression

Intercept	-0.42314
Slope	0.126235
Correlation	0.996814

Validity criteria fulfilled:

yes

Conclusions:

The 48-LC50 was 8 mg/L (95% CL: 6.1-10.8 mg/L).

Executive summary:

The toxicity of tributylamine was tested according to the EPA OTS 797.1300 guideline, which corresponds to OECD TG 202. 20 animals per concentration (4 replicates, 5 animals per vessel; control: 30 animals, 6 replicates, 5 animals per vessel) were exposed to tributylamine under semistatic conditions (test medium renewal after 24 h). A positive control (potassium dichromate) was run, the results were valid.

The test concentrations were ( nominal/measured): 5.00/n.d., 10.0/1.27, 20.0/n.d., 40.0/3.52, 80.0/n.d., 160/20.0, and 320/n.d. mg/L. The test concentrations were analytically verified. The retrieval rates for tributylamine were low (approx. 13 %), therefore the effects were estimated from measured test concentrations.

The validity criteria were met.

The 48-h EC50 was estimated to be 8 mg/L (95% CL: 6.1-10.8 mg/L).

Description of key information

Waterflea (Daphnia magna): 48-h EC50 = 8 mg/L (OECD 202; Pedersen, 2003)

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

8 mg/L

Additional information

Results for this endpoint are available from three sources, but only one meets important criteria of today standard methods. Therefore the GLP guideline study from Pedersen (2003) was selected as key study, which exposed Daphnia magna to tributylamine for 48-h under semi-static conditions with analytical monitoring.

Endpoint	Organism group	Species	Value [mg/L]	Reliability	Remark	Source
Tributylamine (CAS 102-82-9)
48-h EC50	Aquatic invertebrates	Daphnia magna	8 mg/L (95% CL: 6.1-10.8 mg/L)	1 (key study)	analytically verified concentrations; semi-static	Pedersen (2003)

Based on this study, tributylamine is considered acutely toxic to aquatic invertebrates. TBA has been found to be stable in test solutions, based on TOC measurements in a screening test (without organisms) according to OECD 202 (>80% for 48 h; BASF, 2014).