Registration Dossier

Toxicological information

Carcinogenicity

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Administrative data

Description of key information

After oral ingestion (feed) of coal tar, the target organs of tumorigenicity in particular included lung and liver.
Following inhalation, no exposure-related tumours were observed in organs other than the lung of rats exposed to coal-tar pitch fumes (aerosol) derived from heated pitch material (750 °C) for 43 or 86 weeks, 17 h/d, 5 d/wk.

Key value for chemical safety assessment

Carcinogenicity: via oral route

Endpoint conclusion
Endpoint conclusion:
adverse effect observed
Dose descriptor:
NOAEL
12 mg/kg bw/day
Study duration:
chronic
Species:
rat

Carcinogenicity: via inhalation route

Endpoint conclusion
Endpoint conclusion:
adverse effect observed
Dose descriptor:
LOAEC
1.1 mg/m³
Study duration:
chronic
Species:
rat

Carcinogenicity: via dermal route

Endpoint conclusion
Endpoint conclusion:
adverse effect observed
Dose descriptor:
T25
Study duration:
chronic
Species:
mouse
Quality of whole database:
The derived and adjusted T25 is estimated to be 0.06 µg/(cm2*d) (related to 5 d/wk) (area-specific dose) [note: In the FhI study, the development of skin (local) tumors were investigated. Therefore, exposure data are provided as skin-area specific doses. However, the electronic system does not enable to do so. On the other hand, to specify a body-mass related dose for a local effect makes no sense.

Additional information

Carcinogenicity data are derived from experiments with coal tar and pitch (fumes).

Tars and pitches constitute a family of products that result from different distillation steps of coal (condensation products and distillation residues). Depending on distillation step and distillation temperature, constituents of the products and their portions are variable. But major components of all the distillation products and residues are condensed ring aromatic hydrocarbons in varying composition (i.e. polynuclear aromatic hydrocarbons). Major toxicological effects of these products will primarily be caused by the PAH fraction in the respective substances. Especially for toxicological endpoints that fall into the toxicological action profile of PAH, it is justified to use related tars and pitches as supporting substances to characterise potential effects of pitch, coal tar, high temp.


Justification for selection of carcinogenicity via oral route endpoint:
Feeding study conducted with coal tar, representative for constituents of coal-tar pitch. Result refers to coal tar.

Justification for selection of carcinogenicity via inhalation route endpoint:
Result refers to aerosol of coal-tar pitch (MMAD = 0.5 µm).

Justification for selection of carcinogenicity via dermal route endpoint:
Dermal oncogenicity study in mice conducted with two coal-tar oil for 78 weeks: worst case, representative of constituents in pitch material.

Carcinogenicity: via oral route (target organ): digestive: liver; respiratory: lung

Carcinogenicity: via inhalation route (target organ): respiratory: lung

Carcinogenicity: via dermal route (target organ): other: skin

Justification for classification or non-classification

Pitch, coal tar, high temp. is classified as carcinogenic Cat. 1B according to Regulation (EC) No 1272/2008 on classification, labelling and packaging of substances and mixtures. With Regulation (EU) No 944/2013, harmonised classification is amended to carcinogenic Cat. 1A. This is based on a comprehensive meta-analysis of epidemiological studies on workers in respective industrial settings (see EU Risk Assessment Report for Coal tar pitch, high temperature: EU RAR 323, 2008, Sect. 4.1.2.8.2 and Sect. 4.1.3.2.6). Relevant information is also summarised in the discussion part of the endpoint summary of IUCLID Sect. 7 - Toxicological information (derivation of DN(M)EL) or of CSR Sect. 5.11. - Derivation of DNEL(s) and other hazard conclusions.

Harmonised classification of pitch, coal tar, high temp. according to EU Regulation No 944/2013 is to be applied not before April 1th, 2016. On a voluntary basis, pitch, coal tar, high temp. has been self-classified by the registrant as carcinogenic Cat 1A in advance of the deadline of EU Regulation No 944/2013.