oils, palm, propoxylated

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:

16/04/1993 to 17/06/1993

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Remarks:

Measurement of exposure concentrations was not included. Some study details are absent from the study report.

Qualifier:

according to guideline

Guideline:

other:

Version / remarks:

88/302/EEC, inhibition of cell proliferation in the green alga Scenesdesmus subsicatus 1984.
Also stated according to OECD 1984.

Principles of method if other than guideline:

The study was carried out according to the Guideline 88/302/EEC, which was based on the exposure of green alga Scenesdesmus subsicatus to various concentrations of the test substance over a 72 hour time period. Inhibition of cell proliferation was measured in order to assess inhibition of growth.

GLP compliance:

yes

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source and lot/batch No.of test material: 40050951 (batch number)
- Purity: dry residue 99.97%, C: 73.14% 7 mol% glycerol; 45 mole%fatty acid derivative; 48 mol% of propylene oxide.
- Expiration date of the lot/batch: Not provided
- Purity test date: Not provided
- Appearance: yellowish, liquid

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: not stated
- Stability under test conditions: not stated
- Solubility and stability of the test substance in the solvent/vehicle: not stated
- Reactivity of the test substance with the solvent/vehicle of the cell culture medium: not stated

Analytical monitoring:

no

Details on sampling:

Limited detailed provided on sampling.
pH measured at beginning and end of the study.

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: test substance added to deionised water and stirred for 18 hours. The solution was filtered and the DOC content determined at 120.2 mg/L, correspoding to a product concentration of 164.3mg/L. This served as the stock solution.
- Chemical name of vehicle (organic solvent, emulsifier or dispersant): None
- Evidence of undissolved material (e.g. precipitate, surface film, etc.): Not stated

Test organisms (species):

Scenedesmus sp.

Details on test organisms:

TEST ORGANISM
- Species name: Scenedesmus subspicatus
- Strain: (CHODAT (86.81 SAG))
- Source (laboratory, culture collection): Sourced from a culture from the Institute of Water, Soil and Water Air Hygiene, Berlin.
- Age of inoculum (at test initiation): not stated
- Method of cultivation: From a stock culture, 3 days before the start of the experiment, a subculture was prepared at a cell density of about 20,000 cells / ml.
- Apparatus for culture: The breeding of the algae takes place in sterile ventilated Erlenmeyer flasks on light desks.

ACCLIMATION: No details provided.

Test type:

not specified

Water media type:

not specified

Limit test:

no

Total exposure duration:

72 h

Remarks on exposure duration:

cell concentrations measured at 0, 24, 48 and 72 hours.

Hardness:

Not stated

Test temperature:

24 ± 12 ˚C in a constant temperature room

pH:

8.2 - 8.4 (beginning of the test), 8.0 - 9.4 (end of the test)

Dissolved oxygen:

Not stated

Salinity:

Not stated

Conductivity:

Not stated

Nominal and measured concentrations:

Nominal concentrations: 5.9, 9.9, 16.4, 27.9, 49.3, 82.2, 147.9 mg/L.
The concentrations refer to the anyhydrous product.

Details on test conditions:

TEST SYSTEM
- Test vessel: not stated
- Material, size, headspace, fill volume: not stated
- Aeration: not stated
- Type of flow-through (e.g. peristaltic or proportional diluter): not stated
- Renewal rate of test solution (frequency/flow rate): not stated
- Initial cells density: not stated
- Control end cells density: not stated
- No. of organisms per vessel: not stated
- No. of vessels per concentration (replicates): unclear from report, between 5 and 8
- No. of vessels per control (replicates): unclear from report, between 5 and 8

GROWTH MEDIUM: no details provided

TEST MEDIUM / WATER PARAMETERS: no details provided

OTHER TEST CONDITIONS
- Sterile test conditions: not stated
- Adjustment of pH: not stated
- Photoperiod: not stated
- Light intensity and quality: about 8000 lux, white
- Salinity (for marine algae): not stated

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :
- Determination of cell concentrations: photometrically. Measured by adsorption at 685nm.

Reference substance (positive control):

not specified

Key result

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

> 49.3 mg/L

Nominal / measured:

nominal

Basis for effect:

cell number

Details on results:

It is stated in the report that due to high egg turbidity, the results from the higher concentrations were not taken into account in the evaluation.
The results on the cell numbers, percentage inhibition and growth curves are included in Tables 1 and 2 below. Limited effects were evident for all concentrations in terms of cell numbers, apart from at the highest concentration of 147.9 mg/L.

Results with reference substance (positive control):

Not data

Table 1. Mean values of cell numbers.

Concentration	Mean cell numbers
	Time (hours)
	0	24	48	72
Control	2	2	26	102
5.9	2	5	22	96
9.9	2	6	24	104
16.4	2	6	27	114
27.9	2	4	27	118
49.3	2	4	33	119
82.2	2	12	29	94
147.9	2	16	38	53

Comment: Due to the high turbidity in the higher concentrations the product is above the NOEC value in the algae growth inhibition test.

Table 2. Areas under the growth curves for Scenedesmus subsgicatus, inhibition rates and pH values. Concentrations refer to the anhydrous product.

	Control	5.9	9.9	16.4	27.9	49.3	82.2	147.9
Area under the growth curve	74	70	77	85	85	91.5	93	75.5
Area under growth curve (% of control)		5.4	-4.1	-14.9	-14.9	-23.6	-25.7	-2
Inhibition rate	1.311	1.29	1.317	1.3848	1.359	1.362	1.283	1.092
Inhibition rate (% of control)		1.6	-0.5	-2.8	-3.7	-3.9	2.1	16.7
pH value in test conditions 0 hours	8.3	8.4	8.3	8.4	8.3	8.2	8.2	8.2
pH value in test conditions 72 hours	9.4	9.3	9.3	9.2	9.2	9.0	8.6	8.0

Validity criteria fulfilled:

not specified

Conclusions:

The toxicity of propoxylated palm oil to Scenedesmus subspicatus species was assessed. A 72 hour NOEC was determined at > 49.3 mg/L, however the test substance is not toxic to aquatic organisms at the limit of solubility.

Executive summary:

A reliable, Klimisch 2 study was carried out to assess the toxicity of propoxylated palm oil on the algal species, Scenedesmus subspicatus. The study was carried out according to the Guideline 88/302/EEC, inhibition of cell proliferation in the green alga Scenesdesmus subsicatus 1984. Toxicity was measured at the nominal concentrations: 5.9, 9.9, 16.4, 27.9, 49.3, 82.2, 147.9 mg/L. Analytical determination of actual measured concentrations is not included in the study. The cell numbers were measured at 0, 24, 48 and 72 hour time periods, and used to determine the growth curve and subsequent inhibition of growth.

The results on the cell numbers, percentage inhibition and growth curves are included in Tables 1 and 2. Limited effects were evident in these parameters, apart from at the highest concentration of 147.9 mg/L.  However, it is stated in the report that due to high egg turbidity, the higher concentrations were not taken into account in the results evaluation. The 72 hour NOEC was determined at > 49.3 mg/L, although the test substance is not toxic to aquatic organisms at the limit of solubility.

Description of key information

A reliable, Klimisch 2 study was carried out to assess the toxicity of propoxylated palm oil on the algal species, Scenedesmus subspicatus. The 72 hour NOEC was determined at > 49.3 mg/L. Based on this result, a 72 hour EC50 of >49.3mg/L has calculated, although the test substance is not toxic to aquatic organisms at the limit of solubility.

Key value for chemical safety assessment

EC50 for freshwater algae:

49.3 mg/L