The question of whether “shellac” manicures cause cancer is complex, but the answer primarily relates to the ultraviolet (UV) light used during the process, not the polish itself. The term “shellac” is often used generically to refer to any hybrid gel polish, though it is specifically a brand name for a product that blends traditional nail lacquer with gel components. Like other long-lasting gel polishes, it requires a curing process to harden and become chip-resistant for up to two weeks. This process, which involves short, repeated exposures to UV light, introduces the primary cancer concern associated with the manicure.
The Role of UV Curing Lamps
The most direct link between this type of manicure and potential cancer risk comes from the UV curing lamps. These devices emit UVA radiation, which penetrates deep into the skin and is a known contributor to both skin aging and skin cancer, including melanoma and non-melanoma types. While exposure during a single session is short, the risk is cumulative, meaning frequent, long-term use adds up over time.
Scientific studies show that the UV light from these lamps can induce DNA damage and cause mutations in human cells. Repeated exposure to UVA rays is also responsible for premature photo-aging on the hands, leading to wrinkles, thinning skin, and uneven tone.
Chemical Composition and Ingredient Safety
The polish itself is a hybrid of acrylic monomers and oligomers that requires UV light to initiate polymerization, hardening the liquid into a durable plastic film. These essential chemical components are collectively known as acrylates and methacrylates. While the cured polymer is stable, the uncured monomer molecules are highly reactive and pose a different type of health risk.
The primary safety concern with these chemicals is not systemic carcinogenicity but the potential for allergic contact dermatitis (ACD). Monomers such as 2-hydroxyethyl methacrylate (HEMA) and 2-hydroxypropyl methacrylate (HPMA) are potent allergens. If uncured polish contacts the skin, it can lead to sensitization over time, causing redness, itching, or blisters. Sensitization to acrylates is an issue because these compounds are used in medical and dental materials, potentially complicating future treatments.
Acute and Chronic Non-Cancer Risks
Beyond the chemical and UV concerns, the process of application and removal can cause physical damage to the natural nail. The intensive removal process, which involves soaking the nails in pure acetone, is highly dehydrating. Prolonged exposure to acetone strips the nail plate and surrounding skin of its natural oils, resulting in dryness, brittleness, and discoloration.
The physical act of preparing the nail or removing the polish can also lead to lasting damage. Excessive filing or buffing thins the nail plate, making the nails weak and prone to splitting. If the polish is improperly removed, layers of the natural nail can be ripped away. Poor salon sanitation also introduces the risk of bacterial or fungal infections.
Practical Safety and Mitigation Strategies
Consumers can take proactive steps to minimize the risks associated with hybrid gel manicures. To combat UV exposure, apply a broad-spectrum sunscreen (SPF 30 or higher) to your hands 20 minutes before the curing process begins. Wearing specialized fingerless UV-protective gloves is another effective method to shield the skin while leaving only the nail plate exposed.
To avoid chemical sensitization, ensure the uncured polish never touches the skin, which requires a skilled technician. Choosing reputable salons that use high-quality products and follow proper curing times is important to ensure full polymerization of the acrylates. Limiting the frequency of manicures and moisturizing the nails after removal can help mitigate the chronic effects of dehydration caused by the acetone soak.