What Are MIT Preservatives in Paint?
When choosing paint, most of us spend time thinking about colour, finish and durability. Far fewer of us think about the ingredients inside the tin.
Yet a group of preservatives found in many conventional water-based paints has become a particular concern for people with allergies, eczema and chemical sensitivities.
These chemicals are called isothiazolinones and include the preservative methylisothiazolinone, commonly known as MIT or MI.
If you’ve been advised to look for MIT-free paint, or you’re simply trying to make more informed choices for your home, here’s what you need to know.
What Is MIT?
MIT stands for methylisothiazolinone, a synthetic preservative used to prevent bacteria, mould and fungi from growing in water-based products while they are stored.
Modern emulsion paints contain a high proportion of water, so they need an effective system to prevent the paint from spoiling inside the tin.
For many years, one of the most common solutions has been to use small quantities of preservatives from the isothiazolinone family.
Although these chemicals are effective at preserving paint, methylisothiazolinone is also a well-recognised cause of allergic contact dermatitis.
Which Isothiazolinones Can Be Found in Paint?
People sometimes use the term “MITs” to describe the wider family of isothiazolinone preservatives. Strictly speaking, however, MIT is one particular chemical within that family.
Common isothiazolinones include:
- Methylisothiazolinone (MIT or MI) – CAS 2682-20-4
- Benzisothiazolinone (BIT) – CAS 2634-33-5
- Methylchloroisothiazolinone (CMIT or MCI) – CAS 26172-55-4
- Octylisothiazolinone (OIT) – CAS 26530-20-1
- Dichlorooctylisothiazolinone (DCOIT) – more commonly used in industrial coatings and marine applications
Although their individual properties and uses differ, they all belong to the same preservative family.
A conventional water-based paint may contain one or more of these chemicals.
What Symptoms Can an Isothiazolinone Allergy Cause?
Not everyone will react to isothiazolinones. However, once someone has developed an allergy, exposure to even a small amount may trigger symptoms.
Common reactions include:
- Itchy skin
- Eczema flare-ups
- Red or inflamed rashes
- Blistering
- Cracked or peeling skin
- Swelling around the affected area
The most common reaction is allergic contact dermatitis. This occurs when the immune system becomes sensitised to a substance and reacts when it encounters it again.
Skin contact is the best-established route of exposure, but reactions are not necessarily limited to physically touching wet paint. Airborne exposure from freshly painted surfaces has also been associated with allergic dermatitis in some people who are already sensitised.
Some sensitised individuals have experienced irritation, coughing or other respiratory symptoms after spending time in recently painted rooms. However, because conventional paints contain a mixture of ingredients, it is not always possible to identify which individual ingredient has caused every symptom.
Once an isothiazolinone allergy has developed, the person may need to avoid products containing these preservatives in many areas of daily life, not just paint.
Should You Avoid MIT If You Don’t Have an Allergy?
Not everyone will develop an allergy to isothiazolinones, and many people use conventional paints without experiencing an obvious reaction.
However, some homeowners prefer to reduce their exposure to unnecessary chemicals wherever practical.
Paint is not a product that is used briefly and then removed. It is applied across large areas of the home and remains on the walls for many years.
Choosing a paint formulated without isothiazolinone preservatives can therefore offer additional reassurance, particularly in bedrooms, nurseries and other rooms where you spend a significant amount of time.
Many of us now pay close attention to the ingredients in our food, skincare and household products. The same thinking applies when choosing paint. Our guide How to Choose a Truly Non-Toxic Paint explains the ingredients worth looking out for.
When the same beautiful colour and performance can be achieved without these preservatives, why use them if you don’t have to?
How Is Verus Paint Different?
At Verus Paint, we wanted to rethink what modern paint could be.
Instead of relying on conventional isothiazolinone preservatives such as MIT, BIT or CMIT, Verus uses an innovative system to keep the paint stable without them.
This same intelligent formulation helps make the paint naturally resistant to mould and bacteria, while allowing the finished surface to remain breathable.
Every tin of Verus Paint is:
- 100% VOC free
- Free from MIT, BIT, CMIT and other isothiazolinone preservatives
- Odourless
- Toxin free
- Naturally resistant to mould and bacteria
- Breathable, allowing moisture to move naturally through walls
- Suitable for homes of any age, from modern properties to period buildings
The result is a high-performance paint that delivers exceptional colour without relying on a family of preservatives that many people actively choose to avoid.
Because creating a healthier home shouldn’t mean compromising on colour, finish or performance.
Frequently Asked Questions
Is MIT banned in paint?
No. Isothiazolinone preservatives are still permitted for use in paint, subject to applicable regulations and labelling requirements.
However, they are recognised skin sensitisers, which is why some consumers actively seek out paint formulated without them.
Is MIT the same as a VOC?
No. They are different types of chemical used for different purposes.
VOCs, or volatile organic compounds, evaporate into the air and can contribute to the familiar smell associated with conventional paint.
MIT is a preservative used to prevent bacteria and mould from growing in a water-based product while it is stored.
A paint can therefore be described as low VOC while still containing MIT, BIT or other isothiazolinone preservatives.
Can you buy paint without MIT?
Yes. Verus Paint is formulated without MIT, BIT, CMIT or other isothiazolinone preservatives, while still providing excellent colour, coverage and performance.
Is Verus Paint suitable for people with allergies?
Many customers choose Verus because they are looking for an alternative to conventional paint.
However, every person is different, and no paint can guarantee that an individual will not experience a reaction. Anyone with a diagnosed allergy or significant chemical sensitivity should review the ingredients and technical information carefully before using a new product.
Verus is formulated without VOCs, solvents and isothiazolinone preservatives, including MIT, BIT and CMIT.
Final Thoughts
Most of us don’t think about what is inside a tin of paint. But when that paint will cover the walls of our bedrooms, nurseries and living spaces for years, its formulation deserves consideration.
Understanding what MIT and other isothiazolinone preservatives are allows you to make a more informed decision about the products you bring into your home.
At Verus Paint, we believe you shouldn’t have to choose between beautiful colour, outstanding performance and a thoughtfully considered formulation.
Scientific & Medical Resources
This article is based on information from recognised health and scientific organisations, including:
- The UK Health Security Agency (UKHSA) – guidance on chemical exposure and indoor environments.
- The British Association of Dermatologists – information on allergic contact dermatitis and skin allergies.
- The European Chemicals Agency (ECHA) – information on isothiazolinones and their classification as skin sensitisers.
- The NHS – advice on eczema and contact dermatitis.
Further Reading
If you'd like to learn more about creating a healthier home, you may also find these guides helpful: