Reaction mass of 1,3-dioxane-5,5-dimethanol and 1,3-Propanediol, 2-(hydroxymethyl)-2-[(methoxymethoxy)methyl]-

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:

supporting study

Study period:

August 2008

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Alga, Growth Inhibition Test)

Deviations:

no

GLP compliance:

yes

Analytical monitoring:

no

Vehicle:

no

Details on test solutions:

Method: 10008 mg test item was dissolved in 1000 mL of growth medium with magnetic stirring to provide a stock solution (10000 mg/L). The pH
of the stock solution was adjusted from 4.78 to 8.55 then the stock solution was diluted in growth medium to provide the test solutions.

Test organisms (species):

Raphidocelis subcapitata (previous names: Pseudokirchneriella subcapitata, Selenastrum capricornutum)

Details on test organisms:

TEST ORGANISM
- Common name: Green alga
- Strain: NIVA CHL 1
- Source (laboratory, culture collection): Taken from Toxicon's ongoing culture, which originates from NIVA, Oslo, Norway.

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

72 h

Post exposure observation period:

Not applicable

Hardness:

Not applicable

Test temperature:

21 - 24 ± 2°C

pH:

8.1 ± 0.2 (medium before addition of test material) - no other information provided

Dissolved oxygen:

Not applicable

Salinity:

Not applicable

Nominal and measured concentrations:

Nominal concentrations: 0, 15.6, 31.2, 62.5, 125, 250, 500, and 1000 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel:
- Type (delete if not applicable): closed
- Material, size, headspace, fill volume: 250 mL glass E-type bottles with 100 mL solution.
- Initial cells density: 10000 cells/mL
- Control end cells density: 1040000 (± 13.4% CV)
- No. of vessels per concentration (replicates): Three
- No. of vessels per control (replicates): Six


GROWTH MEDIUM
- Standard medium used: yes, as specified in OECD test guideline 201


OTHER TEST CONDITIONS
- Sterile test conditions: yes
- Adjustment of pH: Stock solution pH adjusted prior to preparation of test solutions.
- Photoperiod: Continuous illumination.
- Light intensity and quality: 100 µE m-2 s-1


EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :
- Determination of cell concentrations: the number of cells/mL was counted by microscope. Sampling performed at 0, 24, 48, and 72 hours.
- Chlorophyll measurement:
- Other:


TEST CONCENTRATIONS
- Spacing factor for test concentrations: 2-fold

Reference substance (positive control):

no

Key result

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

250 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

250 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

biomass

Remarks:

yield.

Key result

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

639 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

347 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

biomass

Remarks:

yield

Details on results:

- Exponential growth in the control (for algal test): yes
- Any stimulation of growth found in any treatment: No (slight increase in growth rates seen at 31.2, 62.5, and 125 mg/L levels relative to the control, but the difference was not determined to be statistically relevant).

Results with reference substance (positive control):

The report states the following:

A qualification test on the alga culture was made on 5 June 2008 to assure the quality of the test animals. ErC50 was 1.5 mg/L, which confirmed that the culture was usitable as a test organism according to OECD TG no. 201.

Reported statistics and error estimates:

The EC-values were calculated by means of graphic interpolation. The NOEC-value is the highest tested concentration not statistically different from the controls (Mann-Whitney U-test p>0.05).

Calculated specific growth and biomass results (72 hours)

Nominal concentration (mg/L)	72 hours Specific growth rate (μ) Mean ± CV (%)
Control	1.55 ± 2.9
31.2	1.57 ± 0.9
62.5	1.56 ± 3.1
125	1.63 ± 0.9
250	1.43 ± 7.5
500	1.00 ± 5.6
1000	0.20 ± 93
	72 h Yield (cells/ml) Mean ± CV (%)
Control	1040000 ± 13.4
31.2	1096667 ± 4.1
62.5	1073333 ± 14.5
125	1320000 ± 4.6
250	740000 ± 31.8
500	190000 ± 18.2
1000	10000 ± 100

Validity criteria fulfilled:

yes

Conclusions:

A 72 hour algal growth inhibition study, test species Raphidocelis subcapitata (formerly known as Pseudokirchneriella subcapitata and Selenastrum capricornutum), was performed to determine the toxic effects of the test substance Polyol PX. The test was conducted according to OECD test guideline 201, and performed to GLP. Based on nominal exposure concentrations the 72 hour ErC50 (growth rate) was calculated to be 639 mg/L and the corresponding no-observed effect concentration (NOEC) was 250 mg/L.

Executive summary:

In a 72 hour acute toxicity study, the cultures of the green alga Raphidocelis subcapitata (NIVA CHL 1) were exposed to Polyol PX at nominal concentrations of 0 (control), 31,2, 62,5, 125, 250, 500, 1000 mg/L under static conditions in accordance with the guideline OECD 201 - Algae, Growth inhibition test. The NOEC and EC50 values based on growth rate were 250 and 639 mg/L, respectively. The % growth inhibition in the treated algal culture as compared to the control ranged from 0 to 90.

 

There were no compound related phytotoxic effects.

 

This toxicity study is classified as supplementary and satisfies the guideline requirements for Algae, Growth Inhibition - toxicity study.

 

Results Synopsis

Test Organism: Raphidocelis subcapitata

Test Type: Static

 

72 hr EC50: 250 mg/L

72 hr NOEC: 639 mg/L

Endpoints Effected: Growth Rate/Yield

Reference 2

Endpoint:

toxicity to aquatic algae and cyanobacteria

Type of information:

experimental study

Adequacy of study:

key study

Study period:

From 15 NOV 2021 to 18 NOV 2021

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Freshwater Alga and Cyanobacteria, Growth Inhibition Test)

Version / remarks:

adopted 23. Mar. 2006, Annex 5 corrected: 28 July 2011

Qualifier:

according to guideline

Guideline:

EU Method C.3 (Algal Inhibition test)

Version / remarks:

Commission Regulation (EU) No. 2016/266 amending Regulation (EC) No. 440/2008, Annex IV, Method C.3: “FRESHWATER ALGAE AND CYANOBACTERIA, GROWTH INHIBITION TEST,” adopted 07. December 2015

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Details on sampling:

- Concentrations: 50-1000 mg/L
- Sampling method: For the calibration, a dilution series in water was prepared, using a derivatized stock solution. The quantification was performed as an area sum of two signals: CPF and Pentaerythritol. The identification of two signals was performed using the reference items by measurement of solutions via GC/FID and GC/MSD.
- Sample storage conditions before analysis: The test item was stored in a closed vessel at room temperature (20 ± 5 °C), in a dry area protected from direct sunlight and the elements

Test organisms (species):

Desmodesmus subspicatus (previous name: Scenedesmus subspicatus)

Details on test organisms:

TEST ORGANISM
- Common name: Green Algae - Chlorophytes
- Strain: 86.81
- Source: MBM Sciencebridge GmbH (Albrecht-von-Haller-Institut für Pflanzenwissenschaften Experimentelle Phykologie und Sammlung von Algenkulturen (SAG)).
- Method of cultivation: The algae are kept as stock culture on solid agar at 2 - 8 °C. From the stock culture, a permanent culture was prepared. From an aliquot of the permanent culture, the pre-culture was prepared.

ACCLIMATION
For the pre-culture an aliquot of the permanent culture was brought into nutrient medium and incubated under continuous lighting for 4 days under test conditions (Lighting: within the specified range of 4440 – 8880 lux; 21.4 – 22.1 °C). The resulting culture grew exponentially. Before usage, the pre-culture was checked for the absence of cell aggregates and the cell number of the culture was determined.

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

72 h

Post exposure observation period:

At the end of the test, the treatments were examined microscopically in order to assess the appearance of the algae and detect abnormalities (e. g. caused by the exposure to the test item).

Test temperature:

21.3 – 22.2 °C

pH:

7.5- 7.7

Nominal and measured concentrations:

10 / 18 / 32 / 56 / 100 mg/L (nominal concentration)

Details on test conditions:

TEST SYSTEM
- Test vessel: glass flasks total volume 65 mL
- Initial cells density: The real cell concentration at the beginning of the test was measured with an electronic particle counter in the blank control solution. This measured value was used as start cell concentration for all replicates.
- No. of vessels per concentration: 3
- No. of vessels per control: 6

GROWTH MEDIUM
- Standard medium used: yes

OTHER TEST CONDITIONS
- Light intensity and quality: within the specified range (4440 – 8880 Lux)

EFFECT PARAMETERS MEASURED:
- Determination of cell concentrations: electronic particle counter.

Reference substance (positive control):

yes

Remarks:

Potassium dichromate K2Cr2O7 (CAS No. 7778-50-9) was used as positive control in a separate reference test. The study was performed under GLP conditions in February and March 2021.

Key result

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

yield

Duration:

72 h

Dose descriptor:

LOEC

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Duration:

72 h

Dose descriptor:

LOEC

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

yield

Duration:

72 h

Dose descriptor:

EC10

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Duration:

72 h

Dose descriptor:

EC10

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

yield

Key result

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

yield

Results with reference substance (positive control):

- Results with Potassium dichromate:
- 72-h EC50 based on growth: 0.73 mg/L (96% CI = 0.69 – 0.76 mg/L)
- 72-h EC50 based on yield: 0.28 mg/L (96% CI = 0.25 – 0.30 mg/L)

Nominal concentration(mg/l)	Parameter	Initial cell density	Cell density at	Cell density at	Cell density at	Growth rate [day-1]	Yield [Cell Concentration/mL]	% Inhibition of growth rate	% Inhibition of Yield
			24 h	48 h	72 h	(0-72 h)	(0-72 h)	(0-72 h)	(0-72 h)
Blank control	Mean	2520	10753	55890	345927	1.64	343407	0	0
	SD	0	799	2514	14584	0.01	14584	-	-
10	Mean	2520	10900	62840	375707	1.67	373187	-1.7	-8.7
	SD	0	790	3924	8696	0.01	8696	-	-
18	Mean	2520	13567	69293	371033	1.66	368513	-1.4	-7.3
	SD	0	3682	3075	22165	0.02	22165	-	-
32	Mean	2520	11567	67140	391907	1.68	389387	-2.5	-13.4
	SD	0	1183	8625	6902	0.01	6902	-	-
56	Mean	2520	10667	63587	392667	1.68	390147	-2.6	-13.6
	SD	0	633	3226	11668	0.01	11668	-	-
100	Mean	2520	11227	65607	400440	1.69	397920	-3	-15.9
	SD	0	324	5069	10131	0.01	10131

Validity criteria fulfilled:

yes

Conclusions:

One valid experiment was performed.
The study was performed using 5 concentrations ranging from 10 to 100 mg/L (nominal).
Inhibition of algae growth was not observed at any of the tested concentrations. Algal growth in the test solutions was even slightly higher than in the control. Therefore. no statistical evaluation was performed and the biological results were reported as a range.

Executive summary:

In a 72 hour acute toxicity study, the cultures of the Chlorophyta Desmodesmus subspicatus (SAG Strain Number= 86.81) were exposed to Polyol PX at nominal concentrations of 10, 18, 32, 56, 100 mg/L under static conditions in accordance with OECD 201 resp. EU C.3. The NOEC and EC50 values based on growth rate and yiels were 100 and >100 mg/L, respectively. The % growth inhibition in the treated algal culture as compared to the control ranged from -18.25 to 0.14.

 

There were no compound related phytotoxic effects.

 

This toxicity study is classified as acceptable and satisfies the guideline requirements for an acute toxicity study with algae and cyanobacteria.

Description of key information

The EC50 and NOEC for Desmodesmus subspicatus based on growth rate and yield were determined to be 100 and >100 mg/L respectively, based on nominal test concentrations. Nominal test concentrations were confirmed analytically.

Key value for chemical safety assessment

EC50 for freshwater algae:

100 mg/L

EC10 or NOEC for freshwater algae:

100 mg/L

Additional information

Two valid studies have been conducted:

 

- A 72 hour algal growth inhibition study, test species Raphidocelis subcapitata (formerly known as Pseudokirchneriella subcapitata and Selenastrum capricornutum), was performed to determine the toxic effects of the test substance Polyol PX. The test was conducted according to OECD test guideline 201, and performed to GLP. Based on nominal exposure concentrations the 72 hour ErC50 was calculated to be 639 mg/L and the corresponding no-observed effect concentration (NOEC) was 250 mg/L. The study is considered as supportive information.

 

- Another 72 h algal growth inhibition study was performed on a different algal species (Desmodesmus subspicatus) and considered as key study. The test was conducted according to OECD test guideline 201, and performed to GLP. Based on nominal exposure concentrations the 72 h ErC50 was calculated to be >100 mg/L and the corresponding no-observed effect concentration (NOEC) was 100 mg/L.