Pyridinium, 1-(phenylmethyl)-, ethyl methyl derivs., chlorides

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:

72 hours, performed 2020

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Alga, Growth Inhibition Test)

Version / remarks:

Including analytical verification

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

Purity: 90.8 % Non-volatiles at 130 °C
Physical State/Appearance: Viscous brown liquid

Analytical monitoring:

yes

Details on sampling:

Analysis of the test preparations at 0 hours showed measured test concentrations to range from 0.0012 to 0.37 mg/L. Analysis of the test preparations at 72 hours showed measured test concentrations to range from 0.00074 to 0.29 mg/L.
Given this decline in measured test concentrations it was considered justifiable to base the results on the geometric mean measured test concentrations in order to give a "worst case".

Vehicle:

no

Details on test solutions:

0Nominal concentrations of 0.0010, 0.0032, 0.010, 0.032, 0.10 and 0.32 mg/L
(three replicate flasks per concentration)

Test organisms (species):

other: Raphidocelis subcapitata

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

72 h

Hardness:

Not specified, but stated to be to OECD standard test media

Test temperature:

Temperature was maintained at 24 ±1 ºC throughout the test

pH:

The pH value of the control cultures was observed to increase from pH 7.7 at 0 hours to pH 9.0 at 72 hours.

Nominal and measured concentrations:

Nominal concentrations of 0.0010, 0.0032, 0.010, 0.032, 0.10 and 0.32 mg/L
Mean measured test concentrations 0.00093, 0.0030, 0.010, 0.033, 0.11 and 0.33 mg/L.

Reference substance (positive control):

no

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

ca. 0.15 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

ca. 0.071 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

biomass

Validity criteria fulfilled:

yes

Conclusions:

The substance is considered toxic to the aquatic environment.

Description of key information

Three studies are reported.  The most sensitive result suggests inhibition of growth rate IC50 0.15 mg/l

Key value for chemical safety assessment

EC50 for freshwater algae:

0.47 mg/L

EC10 or NOEC for freshwater algae:

0.02 mg/L

Additional information

The acute toxicity of MK92K to freshwater green algae was determined in accordance with OECD Guideline 201 (Alga, Growth Inhibition Test) under static conditions.