6,6'-(Ethane-1,2-diylbis(azanediyl))bis(dibenzo[c,e][1,2]oxaphosphinine-6-oxide)“

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:

2014-10-07 - 2014-10-10

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

Principles of method if other than guideline:

The study was performed by the Swiss Federal Laboratories for Materials Science and Technology (Empa), an it is an institution of the Swiss federation.The study was performed according to OECD 2012 but without GLP which does not affect the reliability of this study.

GLP compliance:

no

Remarks:

The study was performed by the Swiss Federal Laboratories for Materials Science and Technology (Empa), an it is an institution of the Swiss federation.

Specific details on test material used for the study:

purity >97 %

Analytical monitoring:

no

Vehicle:

no

Details on test solutions:

Since EMPA FR1 (EDA-DOPO) is poorly soluble, the water accommodated fraction (WAF) approach was used. The loadings were prepared by adding the respective amounts of test item to empty glass vessels, adding algal medium, moderately stirring it for 24 h, and finally sterile-filtering it (0.45 pm).
The resulting water soluble fractions (WSF) were used in the test.

Test organisms (species):

Desmodesmus subspicatus (previous name: Scenedesmus subspicatus)

Details on test organisms:

TEST ORGANISM
- Common name: Desmodesmus subspicatus
- Source (laboratory, culture collection): Institute of Freshwater Ecology, University of Gottingen, D-37073 Gottingen, Germany

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

72 h

Test temperature:

22 ± 2°C

pH:

8

Nominal and measured concentrations:

nominal: 10, 100, 1.000 mg/l

Reference substance (positive control):

no

Key result

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

> 1 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Key result

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

1 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Average specific growth rates between 0 and 72 h

Loading rate (mg/l)	Replicate	GRa^a)	GRa^a) mean values	Coefficient of variation (%)	Inhibition (%)	Inhibition mean value (%)
	A	1.27			-3.0
	B	1.13			8.6
Control	C	1.17	1.23	7.05	5.3	0.0
	D	1.22	b)	C)	1.3
	E	1.24			-0.6
	F	1.38			-11.6
	A	1.36			-9.9
10	B	1.34	1.36	1.5	-8.8	-10.3
	C	1.38			-12.1
	A	1.23			0.5
100	B	1.21	1.21	1 7	1.6	2.0
	C	1.19			3.7
1000	A B C	1.28 1.25               1.26	1.26	1.5	-4.2 -1.2 -2.4	-2.6

a)     Average specific growth rate during the whole test period of 0-3 days

b)        The   biomass in the control cultures increased exponentially by a factor of >16 within the 72h test period corresponding to an average specific growth rate of 1.23 (required: >0.92).

^c)The coefficient of variation of average specific growth rates during the whole test period in replicate control cultures was 7.05% (required: <= 7%). Although this CV is very slightly exceeding the required limit, the outcome of the test is in no case wrong (E_yC₅₀and E_rC₅₀both » 1000 mg/l).

^d)Positive values: algal growth inhibition; negative values: algal growth stimulation

Validity criteria fulfilled:

yes

Conclusions:

With respect to yield (biomass production) no significant effects as compared to the untreated controls were observed at any of the 10, 100 and 1000 mg/l loading rates.
Based on these data the nominal median effect concentration with respect to yield (EyC50/0-3 days) of EMPA FR1 (EDA-DOPO) to Desmodesmus subspicatus was estimated to be >1000 mg/l mg/l loading rate.
The low effect concentrations with respect to yield, i.e. EyC10 and EyC20, were estimated to be >1000 mg/l mg/l, respectively. The no-observed-effect concentration with respect to yield (NOEyC) was 1000 mg/l loading rate.

Executive summary:

The median growth inhibiting concentration (E_rC5o/E_yC₅o) and the no-observed-effect concentration (NOE_rC/NOE_yC) based on the average specific growth rate and the yield (algal biomass production) of EMPA FR1 (EDA-DOPO) to the green alga Desmodesmus subspicatus were investigated over a period of 72 h. Since EMPA FR1 (EDA-DOPO) is poorly soluble, the water accommodated fraction (WAF) approach was applied. No analytical verification of the test item was conducted. The evaluation of the test was based on the loading rates of the test item, assuming the test item to be stable in water over 72 h.The loading rates of EMPA FR1 (EDA-DOPO) were 10, 100 and 1000 mg/l. Three parallel test vessels were used for each loading rate of the test item.With respect to algal growth rate no significant effects as compared to the untreated controls were observed at any of the 10, 100 and 1000 mg/l loading rates. Based on these data the nominal median effect concentration with respect to growth rate (E_rC₅₀/0-3 days) of EMPA FR1 (EDA-DOPO) to Desmodesmus subspicatus was estimated to be >1000 mg/l loading rate. The low effect concentrations for the average specific growth rate, i.e. E_rC-io and E_rC₂₀, were estimated to be >1000 mg/l. The no-observed-effect concentration with respect to growth rate (NOE_rC) was 1000 mg/l loading rate. With respect to yield (biomass production) no significant effects as compared to the untreated controls were observed at any of the 10, 100 and 1000 mg/l loading rates. Based on these data the nominal median effect concentration with respect to yield (E_yC₅₀/0-3 days) of EMPA FR1 (EDA-DOPO) toDesmodesmus subspicatuswas estimated to be >1000 mg/l mg/l loading rate. The low effect concentrations with respect to yield, i.e. E_yC₁₀and E_yC₂₀, were estimated to be >1000 mg/l mg/l, respectively. The no-observed-effect concentration with respect to yield (NOE_yC) was 1000 mg/l loading rate. Commission Regulation (EU) No 286/2011 (i.e. CLP regulation) requires the use of the E_rC₅₀value for classification purposes. Based on an E_rC₅₀value >100 mg/l, EMPA FR1 (EDA-DOPO) is neither regarded as toxic nor harmful to the green algaDesmodesmus subspicatus.

Description of key information

With respect to yield (biomass production) no significant effects as compared to the untreated controls were observed at any of the 10, 100 and 1000 mg/l loading rates.

Based on these data the nominal median effect concentration with respect to yield (EyC50/0-3 days) of EMPA FR1 (EDA-DOPO) to Desmodesmus subspicatus was estimated to be >1000 mg/l mg/l loading rate.

The low effect concentrations with respect to yield, i.e. EyC10 and EyC20, were estimated to be >1000 mg/l mg/l, respectively. The no-observed-effect concentration with respect to yield (NOEyC) was 1000 mg/l loading rate.

Key value for chemical safety assessment

EC50 for freshwater algae:

1 000 mg/L

EC10 or NOEC for freshwater algae:

1 000 mg/L