Why You Shouldn’t Worry About Sodium Hydroxide (Yes! Sodium Hydroxide) in Your Conditioner


There are many horror stories out there of hairdressers mixing hair conditioner with relaxer, but that is not the tale for today. Today, the story is about whether you should worry about hair conditioners which have sodium hydroxide on the ingredients label.

Commercial hair conditioners such as Yes to Carrots, Herbal Essences and Pantene are commonly mentioned in this category. However, there are probably a lot more that use sodium hydroxide and do not mention it or label it as sodium chloride.

Quick Answer

There is almost always no need to worry unless the product is labeled as a silkener or straightening balm.

Long Answer

1. Sodium Hydroxide can be a pH adjuster/buffer

For a standard hair conditioner bottle, it can take as little as 3-5 drops of sodium hydroxide to adjust the pH from very acidic (2/3) to a more skin, scalp and hair friendly pH of around 5-7. As a buffer, the hydroxide ions work to maintain this pH of 5-7 so that it does not change as you use it or possibly put in some small amounts of contaminants e.g if you scoop your conditioner out a jar, your hand may have water or gel or oil on it which could disrupt the conditioner pH. Sodium hydroxide takes care of that.

2. Ok, even if it is just 3-5 drops, could that not be harmful, does it really have to be there?

In order for sodium hydroxide to relax hair, it has to be in the alkaline range (8-10) and it also has to be of high enough concentration, pH alone is not sufficient. Sodium hydroxide as a pH adjuster, is saving you from, at best, having very itchy skin to at worst suffering damage as result of the initial very low pH of around 2-3.

3. If there are only 3-5 drops, why is it on the label?

The manufacturer is being honest. Any ingredient less than 1% does not have to be declared on the ingredients bottle and sodium hydroxide when added as pH adjuster or buffer is hovering right around that 1% mark. Some manufacturers even choose to label it as sodium chloride and not sodium hydroxide.

4. Should I be concerned by sodium chloride on the label?

No, in reality once sodium hydroxide is added to the conditioner, it is the hydroxide part that matters the most for pH and buffering and separates itself off from the sodium part. The sodium part does not like to be ‘naked’ and will quickly find chloride ions and to make the more stable salt sodium chloride.

This is the chemistry if you are interested!

5. When should I be concerned?

-If the product is labelled as a silkener or straightening balm, you should be concerned about sodium hydroxide on the label. Make sure that the product is not designed for straightening hair if that is not what you desire or check its pH yourself before using it.
-If you have ever relaxed your hair, you will be able to recognise that caustic whiff that relaxers give off. This is often a tell-tale sign that sodium hydroxide is present in a high concentration.

Ladies, have you ever been worried about sodium hydroxide in your conditioner? Does this information provide some clarity?