Pitch, coal tar, high-temp.

Toxicity to aquatic algae and cyanobacteria

Administrative data

Endpoint:

toxicity to aquatic algae and cyanobacteria

Type of information:

migrated information: read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Guideline study, meets national standard methods, limited documentation, acceptable for assessment

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2000

Report date:

2000

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

other: Norme Francais EN 28692

Test guideline 2

Qualifier:

equivalent or similar to guideline

Guideline:

EU Method C.3 (Algal Inhibition test)

GLP compliance:

not specified

Test material

Test material information

Constituent 1

Reference substance name:

Benzo[k]fluoranthene

EC Number:

205-916-6

EC Name:

Benzo[k]fluoranthene

Cas Number:

207-08-9

Molecular formula:

C20H12

IUPAC Name:

benzo[k]fluoranthene

Constituent 2

Reference substance name:

Benzo[def]chrysene

EC Number:

200-028-5

EC Name:

Benzo[def]chrysene

Cas Number:

50-32-8

Molecular formula:

C20H12

IUPAC Name:

benzo[pqr]tetraphene

Constituent 3

Reference substance name:

benzo[a]pyrene / benzo[def]chrysene

IUPAC Name:

benzo[a]pyrene / benzo[def]chrysene

Details on test material:

- Name of test material (as cited in study report): benzo(a)pyrene
- Molecular formula (if other than submission substance): C20H12
- Molecular weight (if other than submission substance): 252
- Substance type: organic
- Physical state: solid
- Source: no data
- Analytical purity: no data
- Typical concentration in coal-tar pitch: 1.0 - 1.3 % (data from NL 2008: Coal-Tar Pitch, Annex-XV dossier )

Specific details on test material used for the study:

Details on properties of test surrogate or analogue material (migrated information):
PHYSICO-CHEMICAL PROPERTIES (data from NL 2008: Coal-Tar Pitch, Annex-XV dossier, and WHO 1998: EHC 202, if not otherwise indicated)
- Vapour pressure: 7.3*10^-7 Pa (at 25 °C)
- Water solubility: in freshwater, approx. 1.5 - 3.8 µg/L (20 - 25 °C);
soluble portion of the WSF of coal-tar pitch (loading 100 mg/L): [see 4.8: NOACK 2009_WSF, 100 mg/L nominal]
- Henry's law constant: 0.034 Pa*m3/mol (at 25 °C)
- log Pow: = 6.13 - 6.5
- pKa: not applicable
- Stability in water: limited due to photolytic decomposition and evaporation
- Stability in light: instable in the presence of UV
- pH dependance on stability: not applicable

Sampling and analysis

Analytical monitoring:

yes

Details on sampling:

at 0. 24, 48, and 72 h

Test solutions

Vehicle:

yes

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: Stock solution close to water saturation used for dilution series (no detailed data, see Report p. 34)
- Eluate: no
- Differential loading: no
- Controls: with and without vehicle
- Chemical name of vehicle (organic solvent, emulsifier or dispersant): no data
- Concentration of vehicle in test medium (stock solution and final test solution(s) including control(s)): no data

Test organisms

Test organisms (species):

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

Details on test organisms:

TEST ORGANISM
- Source (laboratory, culture collection): in-house, origin Culture Centre of Algae and Protozoa, University of Cambridge
- Age of inoculum (at test initiation):
- Method of cultivation: weekly inoculation into fresh culture medium

Study design

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

72 h

Test conditions

Hardness:

approx. 215 mg/L (as CaCO3)

Test temperature:

23 +-2°C

pH:

no data

Nominal and measured concentrations:

nominal: not documented
analytical: Estimation of the EC values from measured concentrations at 0, 24, 48, and 72 h,
based on the degradation constant (see Report, p. 40 - 44).

Details on test conditions:

TEST SYSTEM
- Test vessel:
- Type (delete if not applicable): open
- Material, size, headspace, fill volume: Erlenmeyer 250 mL, test volume 100 mL
- Aeration: no
- Initial cells density: approx. 10^4 cells/mL
- Control end cells density:
- No. of vessels per concentration (replicates): 3
- No. of vessels per control (replicates): 6
- No. of vessels per vehicle control (replicates): 3
- agitation: orbital shaker, 150 rpm


TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: synthetic mediumprepared from stock solutions of mineral salts (Report., p. 29/30)

OTHER TEST CONDITIONS
- Sterile test conditions: yes
- Adjustment of pH: no
- Photoperiod: continuous
- Light intensity and quality: 6000 - 8000 lux


EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :
- Determination of cell concentrations: electronic particle counter (Coulter Counter) at 24, 48, and 72 h


TEST CONCENTRATIONS
- Spacing factor for test concentrations: no data
- Range finding study no data

Reference substance (positive control):

yes

Remarks:

potassium bichromate K2Cr2O7

Results and discussion

Effect concentrations

Effect concentrations 1

Duration:

72 h

Dose descriptor:

EC10

Effect conc.:

0.78 µg/L

Nominal / measured:

meas. (TWA)

Conc. based on:

dissolved

Remarks:

test material

Basis for effect:

other: biomass and growth rate

Effect concentrations 2

Duration:

72 h

Dose descriptor:

EC10

Effect conc.:

1.54 µg/L

Nominal / measured:

nominal

Conc. based on:

dissolved

Remarks:

test material

Basis for effect:

other: biomass and growth rate

Remarks on result:

other: 95% C.I.: 1.52 - 1.57 µg/L

Results with reference substance (positive control):

- Results with reference substance valid? yes
- mean ECb50: 0.22 - 0.45 mg/L
- mean ECr50: 0.67 - 1.05 mg/L

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

Adverse effects within the range of water solubility