Pitch, coal tar, high-temp.

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:

- Name of test material (as cited in study report): pitch, coal tar, high temp (coal-tar pitch)
- Physical state: solid
- Stability under test conditions: WSF (water-soluble fraction): limited
- Storage condition of test material: room temperature, exclusion of light
- Treatment of test material prior to testing: the material was milled to a fine-granular powder (grain size < 180 µm)

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: mean of two replicates

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 and 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:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Reason / purpose for cross-reference:

reference to same study

Qualifier:

according to guideline

Guideline:

OECD Guideline 105 (Water Solubility)

Principles of method if other than guideline:

The analytical exercise was part of 21-d daphnia test (long-term toxicity to aquatic invertebrates, see sect. 6.1.4). Parameters determined in test medium (HPLC) were priority PAH (16 EPA + 2).

GLP compliance:

yes (incl. QA statement)

Type of method:

column elution method

Specific details on test material used for the study:

- Name of test material (as cited in study report): coal tar pitch; pitch (coal tar); pitch, coal tar, high-temp
- Physical state: solid
- Density: 1.30 – 1.35 g/m³ (20 °) (DIN 51 757)
- Stability under test conditions: WSF (water-soluble fraction): limited
- Storage condition of test material: room temperature, exclusion of light
- Treatment of test material prior to testing: the test item was crushed with a mortar. Particles of the test item >125 µm were removed by sieving with an analytical sieve with a mesh width of 125 µm.

Key result

Water solubility:

ca. 0.8 - ca. 1.9 other: µg/L (sum of 18 PAH)

Conc. based on:

test mat. (dissolved fraction)

Loading of aqueous phase:

100 mg/L

Incubation duration:

48 h

Temp.:

21 °C

pH:

ca. 7.3 - ca. 8

Remarks on result:

other: range of five replicate samples; WAF was obtained by elution of test material from a generator column for 48 hours

Key result

Water solubility:

ca. 1.3 other: µg/L (sum of 18 PAH)

Conc. based on:

test mat. (dissolved fraction)

Loading of aqueous phase:

100 mg/L

Incubation duration:

48 h

Temp.:

21 °C

pH:

ca. 7.3 - ca. 8

Remarks on result:

other: mean value of five replicate samples; WAF was obtained by elution of test material from a generator column for 48 hours

Details on results:

The maximum dissolved concentration of the test item that could be achieved under the test conditions was analysed:
The test substance concentration of the water-soluble fractions (WSFs) was determined using the fresh test medium at the beginning of each 48h test cycle (Daphnia test).
Results (sum of 18 PAH) ranged from 0.82 - 1.90 µg/L (n=5). The overall mean was 1.33 µg/L (n=5).
NOTE: For calculation of the mean value of each time interval, the measured concentrations of < LOQ(M) were set to ½ LOQ(M) = 15 ng/L. 6 - 12 out of the 18 components (PAH) were below this LOQ on occasion of analysis (Report Tab. 10).

Table 1: Initial concentrations of PAHs in the saturated solution of pitch, coal tar, high temp. (WSF, ng/L) (taken from Report Table 10, means recalculated for the respective time intervals)

Note: Values include background values (see blanks Table 2 below)

Sampling date	2008-10-29 day 0 fresh medium	2008-10-31 day 2 fresh medium	2008-11-04 day 6 fresh medium	2008-11-14 day 16 fresh medium	2008-11-16 day 18 fresh medium	Mean^1) [ng/L]
Naphthalene	< LOQ	< LOQ	< LOQ	< LOQ	< LOQ	< LOQ
Acenaphthylene	< LOQ	< LOQ	< LOQ	< LOQ	< LOQ	< LOQ
1-Methylnaphthalene	< LOQ	< LOQ	< LOQ	< LOQ	32.5	< LOQ
2-Methylnaphthalene	< LOQ	< LOQ	43.1	< LOQ	63.9	< LOQ
Acenaphthene	30.7	< LOQ	84.5	54.1	132	63.3
Fluorene	< LOQ	< LOQ	49.8	91.0	98.9	53.9
Phenanthrene	247	153	296	185	380	252
Anthracene	53.0	31.1	72.5	40.9	82.3	56
Fluoranthene	395	195	379	176	445	318
Pyrene	326	158	297	141	280	240
Benz[a]anthracene	102	52.6	78.8	35.7	90.3	71.9
Chrysene	95.2	50.4	69.8	36.0	91.3	80.1
Benzo[b]fluoranthene	44.4	< LOQ	42.3	< LOQ	49.5	33.2
Benzo[k]fluoranthene	< LOQ	< LOQ	< LOQ	< LOQ	< LOQ	< LOQ
Benzo[a]pyrene	47.0	< LOQ	47.8	< LOQ	52.0	35.4
Dibenz[ah]anthracene	< LOQ	< LOQ	< LOQ	< LOQ	< LOQ	< LOQ
Benzo[ghi]perylene	< LOQ	< LOQ	< LOQ	< LOQ	< LOQ	< LOQ
Indeno[1,2,3-cd]pyrene	< LOQ	< LOQ	< LOQ	< LOQ	< LOQ	< LOQ
Sum of 18 PAHs	1475	820	1566	910	1898	1330

LOQ = Limit of quantification of the analytical method (30 ng/L for each analyte)

¹⁾  For calculation of the mean value, the measured concentrations < LOQ were set to ½ LOQ (15 ng/L).

Table 2: Concentrations of PAHs in the blank controls (taken from Report, Table 11) (WSF, ng/L)

Sampling date	2008-10-29 day 0 fresh medium	2008-10-31 day 2 fresh medium	2008-11-04 day 6 fresh medium	2008-11-14 day 16 fresh medium	2008-11-16 day 18 fresh medium
Naphthalene	< 30 % LOQ	15.1	10.6	19.4	14.6
Acenaphthylene	< 30 % LOQ	< 30 % LOQ	< 30% LOQ	< 30 % LOQ	< 30 % LOQ
1-Methylnaphthalene	< 30 % LOQ	11.3	< 30% LOQ	< 30 % LOQ	< 30 % LOQ
2-Methylnaphthalene	12.0	20.1	14.0	23.1	23.3
Acenaphthene	< 30 % LOQ	< 30 % LOQ	< 30% LOQ	< 30 % LOQ	< 30 % LOQ
Fluorene	< 30 % LOQ	< 30 % LOQ	< 30% LOQ	136	35.3
Phenanthrene	16.9	45.6	< 30% LOQ	13.4	26.4
Anthracene	< 30 % LOQ	< 30 % LOQ	< 30% LOQ	< 30 % LOQ	< 30 % LOQ
Fluoranthene	11.1	15.3	< 30% LOQ	< 30 % LOQ	< 30 % LOQ
Pyrene	< 30 % LOQ	< 30 % LOQ	< 30% LOQ	< 30 % LOQ	< 30 % LOQ
Benz(a)anthracene	< 30 % LOQ	< 30 % LOQ	< 30% LOQ	< 30 % LOQ	< 30 % LOQ
Chrysene	< 30 % LOQ	< 30 % LOQ	< 30% LOQ	< 30 % LOQ	< 30 % LOQ
Benzo(b)fluoranthene	< 30 % LOQ	< 30 % LOQ	< 30% LOQ	< 30 % LOQ	< 30 % LOQ
Benzo(k)fluoranthene	< 30 % LOQ	< 30 % LOQ	< 30% LOQ	< 30 % LOQ	< 30 % LOQ
Benzo(a)pyrene	< 30 % LOQ	< 30 % LOQ	< 30% LOQ	< 30 % LOQ	< 30 % LOQ
Dibenz(a,h)anthracene	< 30 % LOQ	< 30 % LOQ	< 30% LOQ	< 30 % LOQ	< 30 % LOQ
Benzo(ghi)perylene	< 30 % LOQ	< 30 % LOQ	< 30% LOQ	< 30 % LOQ	< 30 % LOQ
Indeno(1,2,3-cd)pyrene	< 30 % LOQ	< 30 % LOQ	< 30% LOQ	< 30 % LOQ	< 30 % LOQ
Sum of 18 PAHs [ng/L]	40.0	107	24.6	192	100

LOQ  = Limit of quantification of the analytical method (30 ng/L for each analyte), values below LOQ are given in bold italics.

Description of key information

At a loading of 1000 mg pitch/L, the mean TOC of the water-soluble fraction (WAF) was 0.242 mg/L. at 20 °C. A total of 0.8 to 1.4 µg/L was found in the WAF of a loading of 100 mg/L at 21 °C, related to the 16 EPA PAHs.

Key value for chemical safety assessment

Water solubility:

0.002 mg/L

at the temperature of:

20 °C

Additional information

The stated water solubility relates to the marker substance, benzo[a]pyrene (EU 2008, Tab. 1.6). Water solubility of pitch, coal tar, high-temp. is different and depends on the load of the solution (see aside).

Sources:

EU (2008) Coal-Tar Pitch, high temperature - Risk Assessment. European Union Risk Assessment Report, The Netherlands [URL: https://echa.europa.eu/documents/10162/433ccfe1-f9a5-4420-9dae-bb316f898fe1]

According to EU 2008, presented data from:

Mackay D, Shiu WY, Ma KC (1992). lllustrated Handbook of Physical-Chemical Properties and Environmental Fate of Organic Chemicals. Lewis Publishers, Boca Raton, FL.