3-(D-gluconoylamino)propyl(2-hydroxyethyl)dimethylammonium chloride

Toxicity to aquatic algae and cyanobacteria

Administrative data

Endpoint:

toxicity to aquatic algae and cyanobacteria

Type of information:

experimental study

Adequacy of study:

key study

Study period:

03 Mar 2017-18 May 2017

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2017

Report date:

2017

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

2006; Annex 5 corrected 28 July 2011

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

3-(D-gluconoylamino)propyl(2-hydroxyethyl)dimethylammonium chloride

EC Number:

257-440-3

EC Name:

3-(D-gluconoylamino)propyl(2-hydroxyethyl)dimethylammonium chloride

Cas Number:

51812-80-7

Molecular formula:

C13H29N2O7.Cl

IUPAC Name:

1-Propanaminium, 3-(D-gluconoylamino)-N-(2-hydroxyethyl)-N,N-dimethyl-, chloride

Test material form:

liquid: viscous

Details on test material:

CR Test item 207516/A
Identification Quaternium-22
Appearance Brown paste (determined by Charles River Den Bosch)
Batch 0001954895
Purity/Composition > 90%
Test item storage In refrigerator (2-8°C)
Stable under storage conditions until 16 June 2017 (retest date)

Specific details on test material used for the study:

Test item 207516/A
Identification Quaternium-22
Appearance Brown paste (determined by Charles River Den Bosch)
Batch 0001954895
Purity/Composition > 90%
Test item storage In refrigerator (2-8°C)
Stable under storage conditions until 16 June 2017 (retest date)

Sampling and analysis

Analytical monitoring:

yes

Details on sampling:

Frequency at t=0 h and t=72 h
Volume 2.0 mL from the approximate centre of the test vessels
Storage Not applicable, samples were transferred to the analytical laboratory at the Test Facility and analysed on the day of sampling.
At the end of the exposure period, the replicates with algae were pooled at each concentration before sampling.

Test solutions

Vehicle:

no

Details on test solutions:

Preparation of test solutions started with the highest concentration of 100 mg/L applying a 19- minute period of magnetic stirring to accelerate the dissolution of the test item in medium. Lower test concentrations were prepared by subsequent dilutions of the highest concentration in test medium. All test solutions were clear and colorless at the end of the preparation procedure.
After preparation, volumes of 50 mL were added to each replicate of the respective test concentration. Subsequently, 1 mL of an algal suspension was added to each replicate providing a cell density of 104 cells/mL.

Test organisms

Test organisms (species):

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

Details on test organisms:

Source: In-house laboratory culture.
Reason for selection: This system is a unicellular algal species sensitive to toxic items in the aquatic ecosystem and has been selected as an internationally accepted species.
Stock culture: Algae stock cultures were started by inoculating growth medium with algal cells from a pure culture on agar. The suspensions were continuously aerated and exposed to light in a climate room at a temperature of 21-24°C.
Light intensity: 60 to 120 µE/m2/s when measured in the photosynthetically effective wavelength range of 400 to 700 nm.
Stock culture medium: M1; according to the NPR 6505

Study design

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

72 h

Test conditions

Hardness:

0.24 mmol/L (24 mg CaCO3/L)

Test temperature:

between 22 and 23°C

pH:

7.7-8.0

Nominal and measured concentrations:

10, 18, 32, 56 and 100 mg/L

Reference substance (positive control):

yes

Remarks:

potassium dichromate

Results and discussion

Effect concentrations

Effect concentrations 1

Key result

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

76 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Remarks:

analytically confirmed nominal concentrations

Basis for effect:

growth rate

Remarks on result:

other: 95% CI: 72 - 80 mg/L

Effect concentrations 2

Key result

Duration:

72 h

Dose descriptor:

EC10

Effect conc.:

30 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Remarks:

analytically confirmed nominal concentrations

Basis for effect:

growth rate

Remarks on result:

other: 95% CI: 27 0 24 mg/L

Effect concentrations 3

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

18 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Remarks:

analytically confirmed nominal concentrations

Basis for effect:

other: Growth rate and yield

Details on results:

Growth rates were in the range of the controls at analytically confirmed nominal concentrations from 10 to 18 mg/L during the 72-hour test period, whereas the growth rate of algae exposed to nominal 32 and higher were increasingly reduced. Statistically significant inhibition of growth rate was found at the three highest test concentrations.
Inhibition of yield increased with increasing concentration of Quaternium-22 from 18 mg/L upwards resulting in 95% inhibition at the highest test concentration. Statistically significant inhibition of yield was found at test concentrations of nominal 32 mg/L and higher.
Microscopic observations at the end of the test revealed a normal and healthy appearance of the algal cells exposed to all test concentrations when compared to the control.

Results with reference substance (positive control):

The EC50 for growth rate inhibition (72h-ERC50) was 1.2 mg/L with a 95% confidence interval ranging from 1.1 to 1.2 mg/L. The historical ranges for growth rate inhibition lie between 0.82 and 2.3 mg/L. Hence, the 72h-ERC50 for the algal culture tested corresponds with this range.
The EC50 for yield inhibition (72h-EYC50) was 0.43 mg/L with a 95% confidence interval ranging from 0.42 to 0.44 mg/L. The historical ranges for yield inhibition lie between 0.43 and 1.1 mg/L. Hence, the 72h-EYC50 for the algal culture tested corresponds with this range.

Any other information on results incl. tables

Growth Rate And Percentage Inhibition During the Final Test:

Quaternium-22 Nominal conc. (mg/L)	Mean	Std. Dev.	n	%Inhibition
Control	1.357	0.0524	6
10	1.312	0.0455	3	3.3
18	1.313	0.0558	3	3.3
32	1.220	0.0590	3	10.1*
56	0.899	0.0606	3	33.8*
100	0.474	0.0407	3	65.1*

* effect was statistically significant

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

Under the conditions of the present study with Pseudokirchneriella subcapitata, Quaternium-22 reduced growth rate and inhibited the yield of this fresh water algae species significantly at analytically confirmed nominal concentrations of 32 mg/L and higher.
The EC50 for growth rate inhibition (72h-ERC50) was 76 mg/L with a 95% confidence interval ranging from 72 to 80 mg/L.
The EC50 for yield inhibition (72h-EYC50) was 38 mg/L with a 95% confidence interval ranging from 34 to 42 mg/L.
The 72h-NOEC for growth rate inhibition and the 72h-NOEC for yield inhibition were 18 mg/L.