Hair spray

Hair spray (also hair lacquer or spritz) is a common cosmetic product that is sprayed onto hair to keep it stiff or in a certain style. The spray can be dispensed from a pump or aerosol spray nozzle.

Modern hair sprays were developed around the time of the aerosol can in the 1940s, and the first patents describing copolymers for hair styling were published in the 1940s.

Hair spray products are a blend of simple industrial polymers that provide structural support to hair. These frequently include copolymers of polyvinylpyrrolidone (PVP) and polyvinyl acetate (PV). This copolymer mixture is usually modified to achieve the desired physical properties (adhesive strength, foaming, etc.), using plasticizers such as aminomethyl propanol, surfactants such as benzalkonium chloride, and other agents like dimethicone.

These active ingredients make up only a small portion of a hairspray (aerosol can). The majority of a canister is filled with volatile solvents necessary to solubilize and aerosolize the copolymer mixture. These include simple alcohols like ethanol or tert-butanol to solubilize the active ingredients, and dimethyl ether or mixed hydrocarbons as propellants.

The copolymer mixture, solubilizing agents, and propellants are usually highly volatile and flammable (like most aerosols). For this reason, hair sprays have been classically used for combustion in potato cannons, and have been banned as carry-on items by most airport security agencies.

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