Occupational skin disease according to BK 5102

The wording of the occupational disease (BK) 5102 reads: "Skin cancer or skin changes prone to carcinogenesis caused by soot, crude paraffin wax, tar, anthracene, pitch or similar substances".

Polycyclic hydrocarbon compounds such as soot, crude paraffin, tar, anthracene, pitch or similar substances can cause occupational squamous cell carcinoma, basal cell carcinoma, etc. Bowen³s carcinoma and in situ carcinomas such as Bowen³s disease or actinic keratoses. The recognition of these tumours is examined according to §9 Abs.2 Sozialgesetzbuch (SGB) VII.

Soot as finely flaked coal dust is produced by incomplete combustion of hydrocarbons, e.g. in coking plants and coal gasification. Carbon black is used in the manufacture of graphite and carbon electrodes. It is also used in the manufacture of ink, paints, plastics and especially in the rubber industry. Raw paraffin wax is obtained from bituminous lignite, oil shale, crude oil and natural wax; raw paraffin wax is used in the match, paper and explosives industries. Purified paraffin wax contains no carcinogenic substances. Tar as a distillation product of hard coal and lignite, peat and wood is extracted in coking plants and gas factories and is also used in roofing felt and hard coal briquette factories, in wood impregnation and in road construction.

Anthracene is a product of tar distillation. Tar is used as a raw material in road construction, paint production, wood impregnation, and the production of paints and roofing felt. Pitch is the last residue of tar distillation. It is used as a binder in the production of coal briquettes, cable insulation, roofing felt, varnish, etc.

"Similar substances" are those with similar biological effects. These include, for example, various earth waxes, asphalts, mineral oils, lubricating oils, cylinder oils and drilling oils, with boiling points of > 300° C.

Persons involved in the extraction, production, processing of the use of these products are at risk, depending on their content of carcinogenic substances.

Exposure and absorption of these products may occur directly by skin contamination and/or aerogenically via the airways by dust and vapours, which are mainly produced when the products are heated or radiated. Exposure to sunlight, heat and mechanical stimuli may have an additive effect.

Exposure to the above mentioned products may cause local irritation. Further exposure may cause brownish spotted hyperpigmentation, folliculitis and (tar) acne to develop in the chronically contaminated areas.

Late consequences are single or multiple, different sized tar or pitch black spots. These verrucous skin growths tend to carcinomatous degeneration. The pitch and tar warts may appear after a relatively short time, but in many cases only after several years or decades.

The lesions develop in the directly contaminated areas, especially on the face and back of the hands, also on the forearms, lower abdomen and scrotum.

Their development is still possible even after exposure has ceased. The latency period in which invasive squamous cell carcinomas develop from tar or pitch black is on average 3 to 4 years.

The evaluation of the data on tumour latency periods in exposed workers showed an average latency of 29.1 years for squamous cell carcinomas and 36.0 years for basal cell carcinomas. These long periods of time must be taken into account accordingly in the workplace anamnesis.

1. Bauer A (2016) Skin cancer as an occupational disease. dermatologist 67: 884-890
2. Boffetta P et al (1997) Cancer risk from occupational and environmental exposure to polycyclic aromatic hydrocarbons.Cancer Causes Control 8:444-472.
3. Letzel S et al(1998) Occupationally related tumors in tar refinery workers. J Am Acad Dermatol 39:712-720.