Oleic acid, compound with (Z)-N-octadec-9-enylpropane-1,3-diamine

Toxicity to microorganisms

Link to relevant study record(s)

Reference

Endpoint:

activated sludge respiration inhibition testing

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

23-05-1995

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Non-GLP, No certificate of Analyses included. 30 minutes exposure for a sorbing substance.

Qualifier:

according to guideline

Guideline:

OECD Guideline 209 (Activated Sludge, Respiration Inhibition Test

GLP compliance:

no

Analytical monitoring:

no

Vehicle:

no

Details on test solutions:

A stock suspension was used of 1 g/L.
The test was performed using the following test concentrations: Control (duplicate), 6.3, 12.5, 25, 50 and 100 mg/L

Test organisms (species):

activated sludge of a predominantly domestic sewage

Details on inoculum:

Secondary activated sludge was obtained from the WWTP Nieuwgraaf in Duiven. The WWTP Nieuwgraaf is an actvated sludge plant treating predominantly domestic waste water. The activated sludge concentration in the incubation vessels was 1.0 g DW/L.

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

30 min

Hardness:

Sythetic sewage feed was used: This was made by dissolving 16 peptone, 11 g meat extract, 3 g Urea, 0.7 g NaCl, 0.4 g CaCl2.2H2O, 0.2 g MgSO4.7H2O and 2.8 g K2HPO4 in one liter of deionized water.

Test temperature:

21 °C

pH:

pH ranged from 6.7 to 7.3

Nominal and measured concentrations:

Control (duplicate), 6.3, 12.5, 25, 50 and 100 mg/L nominal

Details on test conditions:

The activated sludge respiration inhibition test was performed according to OECD test guideline 209. In this test the respiration rate of activated sludge fed with a standard amount of synthetic sewage was measured. The respiration rate of the same activated sludge in the presence of various concentrations of the test substance under otherwise identical conditions was also measured.

Duration:

30 min

Dose descriptor:

other: EC20

Effect conc.:

10.7 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

inhibition of total respiration

Remarks:

respiration rate

Duration:

30 min

Dose descriptor:

EC50

Effect conc.:

25.1 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

inhibition of total respiration

Remarks:

respiration rate

Remarks on result:

other: 95% conf. lim. 24.6 - 25.7

Duration:

30 min

Dose descriptor:

other: EC80

Effect conc.:

58.7 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

inhibition of total respiration

Remarks:

respiration rate

Details on results:

The control respiration rates are within 0% of each other

Reported statistics and error estimates:

The respiration rate was expressed as a percentage of the mean of two controls of the respiration rate: (1 - 2Rs/(Rc1 + Rc2))*100 = percentage inhibition where: Rs = oxygen consumption rate at tested concentration of the test substance; Rc = oxygen consumption rate of controls.
The EC values were computed from the best fitted lines (least square method) through the points given by the probit of the percentage inhibition and the logarithm of the concentration of the test substance. Confidence limits were computed based on Fieller's Theorem.

Respiration rates of the activated sludge, inhibition percentages, probit values and pH at various concentrations of test substance.

Concentration mg/L	Activity mg O2/min.L	Inhibition %	Probit	pH
Control	0.24	-		6.7
Control	0.24	-		6.7
100.0	0.00	100	8.10	7.2
50.0	0.06	75	5.67	6.8
25.0	0.12	50	5.00	6.8
12.5	0.18	25	4.33	6.8
6.3	0.22	8	4.59	6.8

Validity criteria fulfilled:

yes

Conclusions:

Activated sludge EC50 (30 min) of Duomeen O = 25.1 mg/L

Executive summary:

In order to predict effects of chemicals in the environment and in biological waste water treatment plants, an activated sludge respiration inhibition test was performed. The toxicity to activated sludge was determined in accordance with OECD test guideline 209

The toxicity of Duomeen O to activated sludge was determined by measuring the respiration ratee after a contact time of 30 minutes at various concentrations of the test substance. The inhibitory effect of Duomeen O at a perticular concentration was expressed as a percentage of the two controls. From the results ECvalues were calcualted. The EC50 of Duomeen O for activated sludge is 25.1 mg/L with 95% CL of 24.6 and 25.7 mg/L. The EC20 and EC80 are 10.7 and 58.7 mg/L resp.

Description of key information

In contrary to studies with soil and sediment where sorption is mainly driven by ionic interaction, is sorption to sludge mainly driven by sorption to organic matter. In soil and sediment both mono- and di-oleates are expected to dissociate completely because through sorption of the cationic groups the dissociation equilibrium will lean strongly to the side of full dissociation but for sorption to organic matter which is mainly based on hydrophobic interaction this dissociation equilibrium lies more to the side of oleyldiamine di-oleates salt. Toxicity to micro-organisms of oleyldiamines and oleyldiamines di-oleates salts are therefore expect to be different. The toxicity of oleyldiamine mono-oleates to sludge bacteria is expected to be somewhere in between. A geometric mean of the two results can unfortunately not be used as the study with oleyldiamine which resulted in an EC50 of 25.1 mg/L is based on 30 minutes exposure and the study with oleyldiamine di-oleates which resulted in an NOEC of 1000 mg/L is based on a 3 hours exposure. As a worst-case the result of the oleyldiamine will be used for read across.

For N-(Oleyl alkyl)- 1,3 -propanediamine di-oleates a 3h NOEC of 1000 mg/L was observed and for N-(Oleyl alkyl)- 1,3 -propanediamine di-oleates are not comparable because the test solutions were prepared differently (bulk approach applied to the di-oleates), toxicity test results from studies with sorbents like soil, sediment and sludge in the terrestrial, benthic and sludge tests should be comparable and should allow read across.

Key value for chemical safety assessment

EC50 for microorganisms:

25.1 mg/L

Additional information

Oleyl diamines di-oleates toxicity to microorganisms

A respiration inhibition test with activated sludge according to OECD Guideline No. 209 was carried out with N-[(9Z)-octadec-9-en-1-yl]propane-1,3-diaminium di[(9Z)-octadec-9-enoate] (oleyldiamine di-oleates).

The test system was activated sludge of the municipal treatment plant of 31137 Hildesheim, Germany. The test was carried out under static conditions with the substance concentrations of 560 - 750 - 1000 mg/L in a geometrical series with a dilution factor of 1.33. Based on the concentration of actiev ingredien, the 3h-NOEC and 3h-EC50 were found to be 1000 and >1000 mg/L respectively (based on active ingredient).

Oleyl diamines toxicity to microorganisms

The lowest EC50 for microorganisms as observed in an OECD 209 test is 25.1 mg/L for  N-9-octa-decenyl-, (Z)- propane-1,3-diamine (7173-62-8)