It is hard to control how deeply the acid penetrates the skin.

It has also been proposed that weak acids such as acetic acid, which are not fully dissociated at physiological pH values, can penetrate taste cells and thereby elicit an electrical response.

Glycolic acid, having the smallest molecular size, is the AHA with greatest bioavailability and penetrates the skin most easily; this largely accounts for the popularity of this product in cosmetic applications.

Similarly, uric acid does not penetrate the blood-brain barrier well.

The corrosive acid itself may penetrate the hull, causing loss of atmosphere.

Chloroacetic acid easily penetrates skin and mucous membranes and interferes with cellular energy production.

It is usually performed in conjunction with a Jessner; which is performed right before, in order to open up the skin, so the retinoic acid can penetrate on a deeper level.

The acid had fortunately only penetrated the varnish layer of the painting and it was fully restored.

The fatty acids of insecticidal soap will also penetrate their thin skins and kill them.

The carboxylic acid coated particles did not penetrate past the stratum corneum.