Paraformaldehyde can be depolymerized to formaldehyde gas by dry heating and to formaldehyde solution by water in the presence of a base or heat.

The resulting formaldehyde gas from dry heating paraformaldehyde is flammable.

This means that, in a well organised theatre, with professional embalmers, very little formaldehyde gas is likely to be released into the atmosphere.

Anhydrous formaldehyde gas readily dissolves in and reacts with water to form an equilibrium solution of methylene glycol.

When heat is applied in the Brazilian blowout process causes the methylene glycol to dehydrate, yielding formaldehyde gas and water vapours.

The crystals boiled away, releasing formaldehyde gas.

Urea-tripolymer has a low fire-hazard rating, but some environmentalists are concerned that it could release formaldehyde gas into the house over time.

It's the four others that worry me, the invisible ones: radon gas, formaldehyde gas, insulation fibers and electromagnetic fields.

Urea-formaldehyde insulation releases poisonous formaldehyde gas, causing indoor air quality problems.

Solutions of formaldehyde can release formaldehyde gas at room temperature and heating such solutions can speed up this process.