Biphenyl-4,4'-diol

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

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Remarks:

A GLP study conducted in accordance with an international test guideline and confirmatory analysis of test solution concentrations.

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Alga, Growth Inhibition Test)

Deviations:

no

GLP compliance:

yes

Analytical monitoring:

yes

Details on sampling:

Samples of test medium taken at 0 and 72 hours,

Vehicle:

yes

Details on test solutions:

Test solutions were prepared at 23 +/_ 2 degree C by dissolution of weighed test item into solvent dimethylformamide (DMF) stock and dilution in diluent medium (OECD culture medium)

Test organisms (species):

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

Details on test organisms:

Internal stock cultures held since 20 June 1996 originating from American Type Culture Collection (ATCC 22662)

Preculture period; May 7, 2004 to May 11, 2004

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

72 h

Post exposure observation period:

NA

Hardness:

NA

Test temperature:

21.9 to 23.1

pH:

0 hours: 7.6 to 7.9
72 hours: 7.8 to 9.2

Dissolved oxygen:

NA

Salinity:

NA

Nominal and measured concentrations:

Nominal concentrations: Control, Solvent control, 0.0500, 0.110, 0.230, 0.480, 1.00, 2.20, 4.70, 10.0 mg/L

Initial measured concentrations at 0 hours: 0.0552, 0.122, 0.254, 0.530, 1.11, 2.46, 5.25 and 11.1 mg/L, equivalent to 110, 111, 110, 110, 111,
112, 112 and 111% of nominal.

72 hour measured concentrations:0.0303, 0.0804, 0.176, 0.375, 0.748, 1.57, 3.75 and 9.7 mg/L equivalent to 61, 73, 77, 78, 75, 71,80 and 97% of
nominal
Geometric mean measured concentrations: 0.041, 0.099, 0.211, 0.446, 0.911, 1.97, 4.44 and 10.4 equivalent to 82, 90, 92, 93, 91, 89, 94 and 104%
of nominal.

Details on test conditions:

3 replicate test vessels per test concentration including controls (diluent and solvent control) with an initial starting cell density of 1 x 10^4 cells/mL. The test was conducted in 300 mL Erlenmeyer flasks containing 100 mL test medium maintained at 23 +/_ 2 degrees C with a constant illumination and light intensity of 4000 Lux Test vessels were shaken at 100 rpm for 72 hours

Reference substance (positive control):

yes

Remarks:

Potassium dichromate

Key result

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

2.15 mg/L

Nominal / measured:

meas. (initial)

Conc. based on:

test mat.

Basis for effect:

biomass

Remarks:

0-72 hours

Remarks on result:

other: 1.86 to 2.48 mg/L

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

7.07 mg/L

Nominal / measured:

meas. (initial)

Conc. based on:

test mat.

Basis for effect:

growth rate

Key result

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

7.73 mg/L

Nominal / measured:

meas. (initial)

Conc. based on:

test mat.

Basis for effect:

growth rate

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

1.11 mg/L

Nominal / measured:

meas. (initial)

Conc. based on:

test mat.

Basis for effect:

growth rate

Key result

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

2.46 mg/L

Nominal / measured:

meas. (initial)

Conc. based on:

test mat.

Basis for effect:

growth rate

Key result

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

0.53 mg/L

Nominal / measured:

meas. (initial)

Conc. based on:

test mat.

Basis for effect:

biomass

Details on results:

No cell abnormalities reported.
The cell concentration in a control and solvent control increased 299 times, and therefore showed normal growth under the test conditions.

Results with reference substance (positive control):

A test with a reference material was conducted at approximatley six monthly intervals using potassium dichromate and the susceptibility of the test organism was investigated. The 72-hour 50% growth inhibition concentration (EbC50) in November, 1996 and afterwards was as follows.
Average ± standard deviation = 0.432 ± 0.0740 mg/L, n= 14

Reported statistics and error estimates:

Bartlett test for homogeneity followed by ANOVA and multiple comparisons test (Williams) using Yukms software Statlight 1 (YukinsCorp, Tokyo)

Analytical results

Nominal concentration (mg/L)	Measured concentrations (mg/L)
	0 hours (mg/L)	% nominal	72 hours	% nominal	geometric mean measured (mg/L)	overall % nominal
0.05	0.0552	110.4	0.0303	60.6	0.041	81.8
0.11	0.122	111	0.0804	73.1	0.099	90.0
0.23	0.254	110	0.176	76.5	0.211	91.9
0.48	0.53	110	0.375	78.1	0.446	92.9
1	1.11	111	0.748	74.8	0.911	91.1
2.2	2.46	112	1.57	71.4	1.97	89.3
4.7	5.25	112	3.75	79.8	4.44	94.4
10	11.1	111	9.7	97.0	10.4	104

Validity criteria fulfilled:

yes

Conclusions:

Test acceptable
The lowest test 72 -hour EC50 was determined to 2.15 mg/L, based on biomass (EbC50).
The 72 -hour ErC50 (based on growth rate) was determined to be 7.73 mg/L.
The lowest test 72 -hour NOEC was determined to 0.53 mg/L, based on biomass.
The 72 -hour NOEC based on growth rate was determined to be 2.46 mg/L.

Executive summary:

A GLP compliant OECD 201 algal inhibition assay (Pseudokirchneriella subcapitata) with 4,4 -biphenol was conducted with confirmation of test solution concentrations at 0 and 72 hours. The test was conducted at nominal concentrations of Control, solvent control, 0.05, 0.11, 0.23, 0.48, 1.0, 2.2, 4.7 and 10 mg/L the concentration range was based on the results of a range finding test.

The results were based on initial measured concentrations at 0 hours: 0.0552, 0.122, 0.254, 0.530, 1.11, 2.46, 5.25 and 11.1 mg/L, equivalent to 110, 111, 110, 110, 111, 112, 112 and 111% of nominal.

The cell concentration in a control and solvent control increased 299 times, and therefore showed normal growth under the test conditions. Based on initial measured concentrations at 0 hours the lowest test endpoint was determined to be the 72 -hour ErC50 of 2.15 mg/L. The 72 -hour ErC50 (based on growth rate) was determined to be 7.73 mg/L.

The lowest test 72 -hour NOEC was determined to 0.53 mg/L, based on biomass. The 72 -hour NOEC based on growth rate was determined to be 2.46 mg/L.

Description of key information

The test was conducted in accordance with GLP and an international test guideline (OECD 201). The test species was Pseudokirchneriella subcapitata and the 72h-EC50 and NOEC values of 7.73 and 0.53 mg/L were based on growth rate as requited by the ECHA endpoint specific guidance.

Key value for chemical safety assessment

EC50 for freshwater algae:

7.73 mg/L

EC10 or NOEC for freshwater algae:

0.53 mg/L

Additional information

A GLP compliant OECD 201 algal inhibition assay (Pseudokirchneriella subcapitata) with 4,4 -biphenol was conducted with confirmation of test solution concentrations at 0 and 72 hours. The test was conducted at nominal concentrations of Control, solvent control, 0.05, 0.11, 0.23, 0.48, 1.0, 2.2, 4.7 and 10 mg/L the concentration range was based on the results of a range finding test.

The results were based on initial measured concentrations at 0 hours: 0.0552, 0.122, 0.254, 0.530, 1.11, 2.46, 5.25 and 11.1 mg/L, equivalent to 110, 111, 110, 110, 111, 112, 112 and 111% of nominal.

The cell concentration in a control and solvent control increased 299 times, and therefore showed normal growth under the test conditions.

Based on initial measured concentrations at 0 hours the test endpoints were determined to be the 72 -hour EbC50 and ErC50 of 2.15 and 7.73 mg/L respectively.

The 72h NOEC was determined to be 0.53 mg/L and 2.46 mg/l based on biomass and on growth respectively.