You may have noticed that on the back label of many of our products we say Preservative-Free (no MIT or BIT). But you may not know what that means... or why it matters, so let’s break it down.
MIT = Methylisothiazolinone and BIT = Benzisothiazolinone
They are both preservatives made from synthetic chemicals and often added to cleaning products (not ours!) to prevent bacteria and mold growth. They’re super effective preservatives, but controversial because they can cause allergic reactions, including skin sensitivities.
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Allergic reactions — Even tiny amounts can cause rashes, irritation, or more serious dermatitis for sensitive people.
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Cumulative sensitivity — The more often you’re exposed, the more likely you are to develop a reaction over time. This is why some people suddenly “develop allergies” to a product they’ve used for years.
Are MIT and BIT “Safe”?
Technically: In low concentrations, regulatory bodies (like the EPA and Cosmetic Ingredient Review) say they are safe for use in cleaning products. The amounts used are usually less than 0.01% in a product.
Practically: For people with sensitive skin, allergies, asthma, or autoimmune conditions, they can be problematic even at those low levels. And if you’re using multiple products with these ingredients daily, your risk of developing sensitivity rises over time.
