Distillates (coal tar), high-temperature, heavy oils

Water solubility

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 105 (Water Solubility)

Deviations:

no

Principles of method if other than guideline:

As a summation parameter, TOC was measured rather than single PAHs.

GLP compliance:

yes (incl. QA statement)

Type of method:

flask method

Specific details on test material used for the study:

- Physical state: solid (here: applied as fine-granular powder < 180 µm)
- Density: 1.30 – 1.35 g/cm³ (20°C) (DIN 51 757)
- Stability under test conditions: WSF (water-soluble fraction): limited
- Storage condition of test material: room temperature, exclusion of light

Key result

Water solubility:

0.242 mg/L

Conc. based on:

other: dissolved organic carbon (DOC)

Loading of aqueous phase:

1 000 mg/L

Incubation duration:

>= 24 - <= 72 h

Temp.:

20 °C

pH:

6.8

Remarks on result:

other: average over 3 time intervals (24, 48, and 72 h) measured in replicate samples

Water solubility:

0.215 mg/L

Conc. based on:

other: dissolved organic carbon (DOC)

Loading of aqueous phase:

100 mg/L

Incubation duration:

72 h

Temp.:

20 °C

pH:

6.7

Remarks on result:

other: average at 72 h (replicate samples)

Solubility Results for Pitch, coal tar, high temp(coal-tar pitch)

(Mean values of two replicates per time interval) (data taken from Table 4 of the report, modified)

Sample		Carbon content [mg/L]
Dilution water^1)		0.732	Mean	Mean over time (24, 48, 72 h)^4)	Mean over time (48, 72 h)^4)	Deviation (48, 72 h) [%]
1000 mg/L	No. 1 (24 h)	0.320	0.289^2)	0.242
	No. 2 (24 h)	0.258
	No. 1 (48 h)	0.988	0.204^3)		0.218	14.5
	No. 2 (48 h)	0.883
	No. 1 (72 h)	0.930	0.233^3)
	No. 2 (72 h)	1.000
100 mg/L	No. 1 (72 h)	0.186	0.215^2)
	No. 2 (72 h)	0.243

1) Dilution water for samples 48, 72 h at 1000 mg/L loading (measured 2010-11-15)

2) Mean values of replicates, dilution water carbon content not subtracted as dilution water carbon content

was 0 mg/L (measured 2010-11-12)

3) Mean values of replicates, dilution water carbon content subtracted (measured 2010-11-15)

4) The time average over 24,48, and 72 h was calculated, thus deviating from the study report in which only the average over 48 and 72 h has been quoted.

Reference 2

Endpoint:

water solubility

Type of information:

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

Adequacy of study:

key study

Justification for type of information:

REPORTING FORMAT FOR THE ANALOGUE APPROACH

1. HYPOTHESIS FOR THE ANALOGUE APPROACH
The target compound, Distillates (coal tar), high-temperature, heavy oils (EC no. 310-231-1; CAS no. 140203-21-0) as well as the read-across (source) compound, pitch (coal tar) [CAS No. 65996-93-2] are coal tar-borne UVCB substances consisting of a complex mixture of polycyclic aromatic hydrocarbons (PAH), predominantly of condensed four to five-ring aromatic ring systems which form a matrix that is practically insoluble in water. The GC-analytical profiles are very similar, and hence will be the physico-chemical and toxicological properties of these structure-related fractions. It is expected that the mammalian systemic and local or environmental toxicity of the target compound will not be higher than that of the read-across compound, pitch (coal tar).

2. SOURCE AND TARGET CHEMICAL(S) (INCLUDING INFORMATION ON PURITY AND IMPURITIES)
The read-across (source) compound, pitch (coal tar), as heavy coal-tar distillate, shows a very similar PAH-profile: This is due to the fact that the considered coal-tar pitch is the high-molecular, "heavy" RESIDUE of a sequential fractionation procedure of coal tar with the temperature increasing, among others under vacuum distillation. On the other hand, the target compound is the high-termperature re-distillate of a high-molecular, heat-treated coal-tar fraction. This is expressed also in the respective fractions of total analysable GC-volatiles which amount to approx. 10% in coal-tar pich, while the GC volatiles of the target compound sum up to a comparable percentage of 13%.

3. ANALOGUE APPROACH JUSTIFICATION
By far the major part of the highly condensed matrix of Distillates (coal tar), high-temperature, heavy oils (EC no. 310-231-1; CAS no. 140203-21-0) is supposed to be biologically unavailable, as is pitch (coal tar ), the read-across source. This means, poor water solubility as well as mammalian and aquatic toxicological profiles are supposed to closely overlap.

Reason / purpose for cross-reference:

read-across source

Principles of method if other than guideline:

Read-across to preceding entry:
Source test material: Pitch (coal tar), high temperature [CAS no. 65996-93-2]
Reference: RÜTGERS 1999a,b

Key result

Water solubility:

0.037 mg/L

Conc. based on:

test mat. (dissolved fraction)

Remarks:

sum of 16 EPA PAH

Loading of aqueous phase:

10 other: g percolated in a column by 1.1 L of water

Incubation duration:

39 wk

Temp.:

22 °C

pH:

7

Remarks on result:

other: total cumulative eluted amount of EPA PAH with weekly renewal of 1 L elution medium

Description of key information

At loadings of 1000 and 100 mg pitch/L, the mean DOC of the water-soluble fraction (WAF) were 0.242 and 0.215 mg/L at 20 °C, respectively. A total of 37 µg (sum of 16 EPA PAH, cumulated after 39 wks) was found in the water extract after 39-fold repetitive weekly elutions of 10 g coal-tar pitch through a percolation column at 22 °C. The water solubilty of the target compound, Distillates (coal tar), high-temperature, heavy oils (EC no. 310-231-1; CAS no. 140203-21-0), is expected to be similar, i.e. in the range of >0.1 mg/L and << 1 mg/L, measured as DOC (see NOACK 2011).

Key value for chemical safety assessment

Water solubility:

0.215 mg/L

at the temperature of:

20 °C