What ingredient in nail products can cause allergic reactions in some clients?

Toluene, dibutyl phthalate (DBP), and formaldehyde are known allergens and sensitizers often found in various nail products, particularly nail polishes and nail hardeners. These chemicals can trigger allergic reactions in some individuals, manifesting as skin irritation, redness, or more severe responses such as contact dermatitis.

Toluene is a solvent that helps dissolve other ingredients in nail products, while DBP is often used as a plasticizer to increase flexibility and durability. Formaldehyde is a preservative and hardener, but it is also a known irritant. Due to their chemical structure and the way they interact with the human immune system, some people may develop sensitivities or allergic reactions.

In contrast, acetone, while it can be drying and irritating to the skin or nails, is less likely to cause true allergic reactions. Alcohol and ethanol are generally well-tolerated in various formulations and do not have the same potential for causing allergic responses as the ingredients mentioned in the correct answer. Understanding the role and potential effects of these ingredients is crucial for ensuring client safety and comfort during nail treatments.