Expert: George Maxwell - 9/20/2007

Question
What are the benefits of mixing "Dimethyl ether" and "Liquefied petroleum gas" in aerosol cans? I believe DME and LPG are used as propellants in aerosol cans, so why not just use one or the other?

Answer
Hi, and thanks for your question.

Normal standard aerosols use LPG -usually butane- as a propellant because it's cheap, unreactive and doesn't deplete the ozone layer like the CFC's that were previously used.

However, LPG isn't a very good solvent for water-based materials (e.g. some fragrances), so you risk some of your product staying in the can whilst the propellant is expelled. DME is a 'broader' solvent (e.g. it dissolves a wider range of materials), but it is both more expensive and more toxic than LPG, so is not as widely used. Mixing the two combines the cheapness of LPG with the better dissolving power of DME. However, such mixes are still more expensive than the standard LPG, and so are only used where the better dissolving power is an important factor. Both DMG and LPG also suffer from the disadvantage of being highly flammable.

Hope this helps!