A similar process occurs in polymers, when products are exposed to aggressive chemicals such as acids and alkalis.

They are not as effective as mechanical methods and should not be used where the waste is fully blocked: the result could be a basin full of aggressive chemical.

It is a very aggressive chemical and cannot be used on the face so other exfoliants would need to be used on the face.

Polymers for example, can be attacked by aggressive chemicals, and if under load, then cracks will grow by the mechanism of stress corrosion cracking.

Each of these pools can be extracted using progressively more aggressive chemicals.

The performance of fluoroelastomers in aggressive chemicals depends on the nature of the base polymer and the compounding ingredients used for molding the final products (e.g. O-rings).

More aggressive chemicals are ruled out because of possible damage and abrasives are unsatisfactory as the aggregate lodges in surface scores.

Humidity and aggressive chemicals can cause corrosion of the packaging materials and leads, potentially breaking them and damaging the inside parts, leading to electrical failure.

Uranium-alloyed steels can be used at very low temperatures; nickel-uranium alloys are resistant to even very aggressive chemicals, including aqua regia.

"You're also going to see it go more into 'aggressive chemicals' such as laundry soaps and herbicides and insecticides," Mr. Thoman said.