What’s to blame for the mass barrier malfunction? Too many creams, serums and other hope in a jar.

“It’s largely a product of our own obsession with squeaky clean and using product upon product upon product,” said Whitney Bowe, a dermatologist in New York. Combine product overload with environmental assaults, and you have a recipe for skin barrier disaster.

Here’s how to avoid that — or to repair the damage.

What the Acid Mantle Is, and Why You Absolutely Must Protect It

The acid mantle is the protective film of natural oils, amino acids and sweat that covers your skin. Damage it with too much scrubbing or neutralize it with alkaline washes and you’re on your way to barrier problems: inflammation, allergies, breakouts.

Talk of the acid mantle (apologies!) means a lot of talk about pH, which, to the surprise of many a chemistry teacher, is the sort of thing beauty addicts love to discuss online these days. So, while alkaline water may be all the rage for health, you definitely don’t want to use it on your (acidic) face.

Cleansing your skin with anything alkaline interferes with the skin’s ability to repair itself and makes it less elastic, Dr. Bowe said. A high pH also encourages the growth of a bacteria called propionibacterium acnes that, as you may guess from the name, plays a major role in many forms of acne. That face wash that is super-foamy and lathery? There’s a fairly good chance it’s alkaline because the ingredients that give it those qualities are high pH.

“The problem is, people want lather to feel clean,” said Emily Parr, a founder of HoliFrog, a line of cleansers that is set to debut in September . “So we had to counter ours with a ton of rich oils to reinforce the barrier.” (The brand’s namesake frog is a nod to its focus on barrier protection; frogs’ skin is so permeable that they can’t survive in toxic environments.)