The facts on Pyrocatechol (1,2-Dihydroxybenzene)

No estimates of current numbers of workers exposed to pyrocatechol (1,2-dihydroxybenzene) in the EU are available.
Pyrocatechol is used in solid and liquid form. Since it can penetrate the skin, both inhalation and dermal contact are relevant exposure routes.
The substance is classified under the EU CLP Regulation as a suspected human carcinogen (Category 1B).

Where risks occur

Occupational exposure to pyrocatechol occurs mainly in chemical and pharmaceutical manufacturing, in technical testing and analysis, and in some downstream industries such as surface treatment, electronics, rubber and plastics, and machinery production.
Professionals at highest risk of exposure to pyrocatechol include chemical process operators, distillation, mixing, and tank farm operators as well as maintenance workers, laboratory technicians, and analytical chemists. Electroplating workers, and workers involved in surface treatment and electronics manufacturing may also be exposed.
Exposure is most likely during activities where the substance is handled in open systems or where containment is not fully effective, such as in mixing or blending tasks, in dipping, coating or in surface treatment processes. Additional exposure may occur during maintenance and cleaning operations.

More about the substance

Pyrocatechol is a solid substance at room temperature, typically appearing as a white to brown crystalline solid that may darken on exposure to air. Pyrocatechol dissolves very well in water and in many organic solvents.

Pyrocatechol is not highly flammable or explosive under normal conditions. However, it can form dust when handled as a solid and may generate aerosols or vapours when heated during industrial processes or when used in liquid form.

It is mainly used as an intermediate in the manufacture of other substances and products. The biggest end-use product categories for pyrocatechol include agrochemicals (crop protection products), flavours and fragrances (e.g. vanillin, household fragranced products), pharmaceuticals and rubber/polymer additives for plastics, tires and rubber goods.

Health risks that may occur

Exposure to pyrocatechol can occur via inhalation of dust or vapours and through skin contact.
Short-term exposure can lead to symptoms such as coughing, throat irritation, eye irritation and skin redness or discomfort. Very high exposures (for example, if swallowed) may result in more severe toxic effects. It may also cause allergic skin reactions after repeated exposure.
Long-term exposure may lead to more serious health effects, including an increased risk of cancer, skin depigmentation, chronic dermatitis and respiratory effects.

What you can do

Substitution should be considered as the priority. Where possible, pyrocatechol should be replaced with less hazardous substances or alternative processes that reduce exposure. Possible substitutes for pyrocatechol (catechol) depend on its role: hydroquinone, resorcinol, and pyrogallol can replace it in some similar chemical or redox applications; gallic acid or tannic acid may work for metal-chelating uses; and ascorbic acid or sodium borohydride can sometimes substitute pyrocatechol as reducing agents. The best alternative depends on the specific application, since these compounds have different reactivity.

Engineering controls are essential where substitution is not possible. These include the use of closed systems and automation, local exhaust ventilation at emission points, and effective general ventilation. These measures help to reduce airborne concentrations of vapours and dust.
Organisational measures include limiting the duration of exposure, providing training to workers (for example on dermal exposure risks), implementing safe handling procedures, and ensuring appropriate cleaning methods that minimise dust generation. Regular monitoring of exposure levels is recommended.

Personal protective equipment should be used as a last line of defence. Special attention should be given to preventing skin contact, due to the ability of the substance to be absorbed through the skin. This includes providing appropriate chemical-resistant gloves and clothing (long-sleeved protective clothing and eye-face protection where splashing is possible), and respiratory protective equipment when necessary.

References: ECHA, IARC, RAC