Serious Skincare's Firmaface ($49.95) advises an unusual procedure: apply all over the face in an even coat "like a mask", remain expressionless for three minutes until it "sets" then splash with water. The result: instant tightening. The secret ingredient: cement.

Actually, it is sodium silicate, an ingredient in the manufacture of cements, passive fire protection, refractories, textile and lumber processing, and automobiles. According to an article in the Wall Street Journal, it is “the designated agent of death for cars surrendered under the federal cash-for-clunkers program,” because of its ability to permanently disable car engines.

This isn't joke, this is Serious Skincare. Actually, they aren't the only ones. If you have a nagging sense of deja vu, that is because sodium silicate is also in Athena 7-Minute Lift, one of the most unpleasant creams I have ever used (it is painted on with a brush and when it sets the sensation is rather like the numb/tingly feeling you get when the dentist's injection starts to wear off).

Sodium Silicate to be a moderate hazard ingredient, and is classified as expected to be toxic or harmful, as a human irritant and as a human toxicant. Nice.

You'll be relieved to know that should you be tempted to get all animated and crack your cement mask, Firmaface has back up in the form of 3-aminopropane sulfonic acid. This is an analogue for GABA, the ingredient that is cropping up in face creams as a neurotransmitter that is supposed to inhibit muscle movement.

Ingredients:

Water, Sodium Silicate, Magnesium Aluminum Silicate, Pentylene Glycol, Calcium Hydroxymethionine, 3-Aminopropane Sulfonic Acid, Aminobutyric Acid, Glycerin, Lecithin, Sorbitol, Retinyl Palmitate, Retinol, Butylene Glycol, Lycium Barbarum Fruit Extract, Macrocystis Pyrifera Extract, Centella Asiatica Extract, Caffeine, Polysorbate 20, Hydroxyethylcellulose, Xanthan Gum, Caramel, Disodium EDTA, Propylene Glycol, Diazolidinyl Urea, Methylparaben, Propylparaben, Yellow 5, Yellow 6.