Spray cans are not as harmless as their daily use may make one think. If as a proof, a specific regulation deals with them, be they cosmetics or not: a European Union Directive, issued on May 20, 1975 and several times updated since then.
For the purpose of this Directive, the term "aerosol dispenser" shall mean any non-reusable container made of metal, glass or plastic and containing a gas compressed, liquefied or dissolved under pressure, with or without a liquid, paste or powder, and fitted with a release device allowing the contents to be ejected as solid or liquid particles in suspension in a gas, as a foam, paste or powder or in a liquid state.
Some twenty pages of this Directive deal with the technical data and other data required to market spray cans (the “3” symbol displayed on the cans is a kind of guarantee that the product meets all the requirements), as these small “bombs” (as French-speaking people often call them) comprise extremely flammable materials, even explosive ones.
Butane, Isobutane or Propane are very often used as propellants for cosmetics, and are classified as extremely flammable.
Further, the Directive requires specific labeling and sentences, which come as ringing the fire-bell for users. The required sentences are displayed on deodorants, hairsprays, shaving foams and gels and other spray cans for moisturizers or glitter used on hair and body; even if written as small letters, better to read them carefully!
What are these sentences?
• Pressurized container.
• Protect from sunlight and do not expose to temperature exceeding 50°C.
• Do not pierce or burn, even after use.
Further, when the propellent is flammable
(the most likely occurrence)
• Flammable or Extremely Flammable (with the flame logo).
• Do not spray on a naked flame or any incandescent material.
• Keep away from a source of ignition. Do not smoke.
• Keep out of the reach of children.
Depending on the materials, other sentences may be displayed:
• Keep away from flame, sources of ignition, sparks, heat sources or electric equipment in use.
• Do not use the product for an application other than its initial purpose.
• Prevent contact with eyes.
• Do not breathe vapor/spray.
• Use only in well-ventilated areas.
• Spray only for short periods in a row (this only for the French market).
Even if the spray can technology is well known and regulated to give a high level of safety and confidence, obviously it is a good idea to follow strictly these few advices!