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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.

The new ECHA CHEM database has been released by ECHA, and it now contains all REACH registration data. There are more details on the transition of ECHA's published data to ECHA CHEM here.

Diss Factsheets

Environmental fate & pathways

Endpoint summary

Administrative data

Description of key information

Additional information

The substance Pitch, coal tar, high-temp., < 1% 4- to 5-membered condensed ring aromatic hydrocarbons [EC no. 701-305-8] [CTPhtht] is a UVCB and consists of a complex combination of highly condensed polycyclic aromatic hydrocarbons (PAH). In a gas chromatographic analysis, only ≤ 1 % of the substances present can be identified. This fraction comprises polycyclic aromatic hydrocarbons with predominantly 5- and 6-membered rings. Concentrations of major constituents (6-membered rings) are in the range of 0.05 to 0.2 %. Benzo[a]pyrene concentration is approx. 0.04 %, while total EPA PAH amount to ca. 0.4 %.

The substance as a whole shows highly inert properties. The solid matrix is insoluble in water and only poorly soluble in organic solvents (e.g. toluene, tetrahydrofuran). Under environmental conditions, there will be no or a very low environmental availability of the substance or its constituents. The very low amount of available constituents consists of 6-membered PAH with their characteristic properties of low solubility and low environmental availability.

Water solubility

CTPhtht is practically insoluble in water: measured TOC values at a loading of 1000 mg/L did not significantly differ from those of the control values. The substance relevant WAF is estimated to be < 0.23 mg/L (Aniol/STZ 2007). This value is considered to overestimate the true water solubility of the substance in the environment.

It is conclusive to assume that Pitch, coal tar, high-temp., < 1% 4- to 5-membered condensed ring aromatic hydrocarbons [EC no. 701-305-8] - although not verified by analysis - will have even a lower water solubility than pitch, coal tar, high-temp. [CAS No. 65996-93-2], the precursor material:

After a 39fold weekly elution of powdered pitch, coal tar, high-temp. from a percolation column, the total cumulative amount of water-extractable EPA PAHs amounted to approx. 370 µg/10g (= ~0.004 %). The water-soluble fraction of single PAHs remained far below their theoretical water solubilities, which confirms that freely available PAHs got gradually depleted. After eluting 100 mg/L of pitch, coal tar, high-temp. in a cycling system, less than 2 µg/L of 16 EPA-PAH were measured in the eluate.

Stability / Degradation

CTPhtht is highly stable under environmental conditions: It is not volatile, not hydrolysable, and not biodegradable.


As CTPhtht consists of a high-molecular chemical matrix structure that is highly water insoluble, the material cannot pass biological membranes due to its complex matrix structure, and hence is not bioaccumulating.


After release into the environment, particles of CTPhtht are expected to interfere and mix with sediment and soil matter with no or little tendency of mobility.