Hair permanents have been around for more than half a century. They gained a bad reputation in the past few decades for being damaging to hair, making it frizzy and brittle. Today, alkaline and acid perms are two popular forms of chemical waves.
Active Ingredients
Alkaline perms contain ammonium thioglycolate, a potent chemical that produces a noxious and undesirable odor in the process. Acid perms contain glyceryl monothioglycolate, a more "gentle" formula; however, it is known to cause allergic sensitivity over frequent exposure, according to Hairfinder.com
pH Levels
Alkaline perms contain a low acidity, between 9.0 and 9.6 pH. Acid perms contain between 4.5 and 7.0. They are much more acidic and require additional heat in order to process.
Time Frame
Alkaline perms process much more quickly than acid perms, taking only about 20 minutes to take effect. They are "cold" perms and don't require additional heat application. Acid perms take much longer because the acidic formula is more gentle on hair.
Effects
Alkaline perms are more popular than acid perms, according to Hairfinder, because they create a more firm curl that stays true to form longer. Acid perms, because they use a more gentle formulation and process, tend to create looser waves.
Candidates
Those with strong, thick, and coarse hair are good candidates for alkaline perms. The potent formula works better on resistant hair types. Those with damaged hair, which is porous, will benefit more from the gentler acid perm or acid-balanced perm that processes faster than true acid waves.
Related Articles
Types of Curly Perms

What Is the Difference Between ...

The Effects of Perm Lotion on Hair ...

Least Acidic & Safest Chemical Hair ...

How to Curl Hair With Foam Rollers
Chemical Curls for African Americans

Chi Thermal Hair Straightener Treatment

Wavy Perm Hairstyles

What Are the Dangers of Getting a Perm?

How to Style a Kanekalon Wig

Why Can't You Wash a Perm?

How to Decide Which Perm is Best for You

How to Control Frizzy Hair for ...

How Do I Choose the Right Perm for My ...
How to Make Grapefruit Seed Extract

How to Get Rid of Calcium Buildup in ...

How Do I Reduce Pain When Plucking Leg ...

How to Make a Perm Curlier

How to Make a Straight Wig Curly

How to Make Extensions Smooth & Silky ...
References
Writer Bio
Karina C. Hernandez is a real estate agent in San Diego since 2004. She has a background in mortgage finance and cosmetics and has written home & garden, housing and beauty articles for multiple internet channels over the past 10 years. She has a B.A. in English from UCLA.