Everzol Red CDN Crude

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:

From January 11, 2010 to March 25, 2010

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Alga, Growth Inhibition Test)

GLP compliance:

yes

Test organisms (species):

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

Details on test organisms:

- Source: In-house laboratory culture

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

72 h

Post exposure observation period:

0, 24, 48 and 72 hours

Nominal and measured concentrations:

0.1, 1.0, 10 and 100 mg/l

Details on test conditions:

- Test vessel: 250ml tissue culture flask
- Test volume: 30 mL
- No. of vessels per concentration (replicates): 6 replicates for the highest test concentration and 3 replicates for other test concentration
- No. of vessels per control (replicates): 6
- Light intensity: 114-127 μE.m-2.s-1

Reference substance (positive control):

yes

Remarks:

potassium dichromate

Duration:

72 h

Dose descriptor:

EC50

Remarks:

for growth rate reduction

Effect conc.:

> 92 mg/L

Nominal / measured:

meas. (TWA)

Conc. based on:

test mat.

Duration:

72 h

Dose descriptor:

EC50

Remarks:

for yield inhibition

Effect conc.:

>= 8.4 - <= 92 mg/L

Nominal / measured:

meas. (TWA)

Conc. based on:

test mat.

Results with reference substance (positive control):

The EC50 for growth rate reduction (ERC50: 0-72h) was 1.2 mg/l and the EC50 for yield inhibition (EYC50: 0-72h) was 0.65 mg/l.

Table 1.Mean cell densities (× 10⁴ cells/ml)

Average conc. Test substance (mg/l)	Exposure time (hours)
	0	24	48	72
Control	1.0	10.0	95.9	488.8
0.083	1.0	8.2	78.6	435.2
0.84	1.0	8.4	82.1	448.3
8.4	1.0	8.7	72.5	339.3
92	1.0	8.9	58.0	137.7

Table 2. Percentage reduction of growth rate (total test period) and percentage inhibition of yield

Average conc. Test substance (mg/l)	Mean growth rate		Yield (0-72 h)
	μ (0-72 h)	Reduction (%)	×10^4cells/ml	Inhibition (%)
Control	0.08599		487.80
0.083	0.08438	1.9	434.20	11.0
0.84	0.08479	1.4	447.32	8.3
8.4	0.08093	5.9	338.34	30.6
92	0.06837	20.5	136.70	72.0

Table 3. Effect parameters

Parameter	Concentration Everzol Red CDN Crude(mg/l)
72h-ERC50	> 92
72h-EY50	8.4-92

Validity criteria fulfilled:

yes

Conclusions:

According to OECD 201 test method, the 72h-ERC50 and the EYC50 of Everzol Red CDN Crude was >92 mg/L and 8.4-92 mg/L respectively.

Executive summary:

This test using the procedures outlined in the NOTOX Study Plan for 492365 and OECD 201 (OECD, 2006). The results of this OECD 201 test for Everzol Red CDN Crude show that test validity criteria was met. In the alga growth inhibition test, the nominal test article concentrations applied were 0.1, 1.0, 10 and 100 mg/L. The average exposure concentration were calculated: 0.083, 0.84, 8.4 and 92 mg/L. Under the test conditions, the EC₅₀ for growth rate reduction and for yield inhibition of Everzol Red CDN Crude was >92 mg/L and 8.4-92 mg/L respectively.

 

Description of key information

Respectively, the 72h-E_RC₅₀ and the 72-E_YC₅₀ of Everzol Red CDN Crude was >92 mg/L and 8.4-92 mg/L for Pseudokirchneriella subcapitata (OECD TG201).

Additional information

The cell densitiesin the control have increased by an average factor of at least 16 within 2 days. The mean coefficient of variation for section-by-section specific growth rates in the control group were not exceed 35%. The coefficient of variation of average specific growth rates during the whole test period in replicate control groups were not exceed 7%. This test validity criteria was met. Under the test conditions, the EC₅₀ for growth rate reduction and for yield inhibition of Everzol Red CDN Crude was >92 mg/L and 8.4-92 mg/L respectively.