What is rosin and where is it found?

Rosin, also called colophony, is the sticky sap from pine and spruce trees. Due to its adhesive nature, rosin is utilized in a variety of products. The table below highlights a selection of products that commonly incorporate rosin, which we might encounter in everyday settings at home or work.

Home/Recreational Sources    

• Cosmetics (e.g. mascaras, lipsticks, eyeshadows, concealer creams, nail varnish)
• Adhesives (e.g. sticking plasters and tapes, glues)
• Medicines (e.g. wart removers, cold sore creams, ostomy products, nappy creams, haemorrhoid creams, sprays)
• Toiletries (e.g.. transparent soaps, hair-removing wax, dental floss, sunscreens, blister creams, and first-aid ointments)
• Household items (e.g. grease removers for clothes, shoe wax, polish for floors, cars and furniture, laundry soaps, fly strips)
• Recreational (e.g. sport racket handles, athletic grip aids, golf club grips, bows for stringed instruments, fireworks, ski wax)
• Chewing gum
• Firewood and pine trees in the garden
• Paper products: one of the largest single uses of colophony is in the manufacture of paper and paperboard

Work Sources

• Paint, varnishes, lacquers, sealants
• Cements, putties
• Linoleum, floor coverings, and tiles
• Printing inks
• Sawdust and resin from pine and spruce
• Asphalt products
• Soldering products
• Corrosion inhibitors
• Grease and lubricant thickener
• Topical medications in dentistry
• Veterinary medications
• Waterproofing agents
• Machine belts in industry

What are the reactions to rosin allergy?

Reactions to contact with rosin in an allergic individual include acute allergic contact dermatitis and asthma. In allergic contact dermatitis, the dermatitis tends to occur 1-3 days after contact with rosin, although occasionally reactions can appear within 24 hours or even more than a week after exposure. The dermatitis tends to be confined to the site of contact with rosin (e.g. hands and forearms after carrying pine wood, although the face may also be involved). Initially the skin becomes red and inflamed, and is generally itchy. As the reaction progresses it may blister and become even more intensely itchy. If exposure is continued, the dermatitis may eventually become chronic with thickened, lichenified skin.