What Is Oxymethylene/Melamine Copolymer?
Oxymethylene/Melamine Copolymer is a synthetic polymer created by linking melamine, a nitrogen-rich compound sometimes used in resins, with formaldehyde units. The result is a network of repeating oxymethylene bridges that give the material strength and flexibility. Developed first for industrial coatings in the mid-20th century, chemists soon recognized its ability to form clear, durable films on skin and hair, leading to its adoption in personal care products.
Manufacturing begins with melamine reacting under controlled heat and pH with formaldehyde. The reaction forms a pre-polymer solution that is then cured to the desired molecular weight. After purification and drying the polymer is milled into a fine powder or dispersed in water, ready to be blended into cosmetic bases.
Within cosmetics you are most likely to find Oxymethylene/Melamine Copolymer in setting sprays, long-wear foundations, peel-off masks, hair styling gels and certain anti-aging primers where a smooth film helps lock other ingredients in place.
Oxymethylene/Melamine Copolymer’s Cosmetic Benefits/Uses
This ingredient is primarily valued for one key performance trait
Film forming: When applied to skin or hair the polymer dries to create a thin flexible layer that improves product durability, resists smudging, reduces transepidermal water loss and can give a smooth uniform finish. In makeup it helps pigments stay put, while in hair care it adds light hold and humidity protection.
Who Can Use Oxymethylene/Melamine Copolymer
Because it forms a lightweight breathable film, Oxymethylene/Melamine Copolymer is generally well tolerated by most skin types including dry, normal, combination and oily. Sensitive skin can usually use it too since the polymer itself is inert, though people with an existing allergy to formaldehyde-releasing resins should approach with care.
The ingredient is synthetic and contains no animal-derived matter so it is suitable for both vegetarians and vegans.
Current safety data does not flag any special risk for pregnant or breastfeeding women when the polymer is used as directed in cosmetics. Still, this is not medical advice and anyone who is pregnant or nursing should have their healthcare provider review any beauty product they plan to use.
Oxymethylene/Melamine Copolymer is not known to increase photosensitivity, so it will not make skin more prone to sunburn.
Potential Side Effects/Adverse Reactions
Responses to topical Oxymethylene/Melamine Copolymer vary from person to person. The points below outline potential side effects but most users will not encounter them when the ingredient is formulated and used correctly.
- Mild redness or irritation in very sensitive skin
- Contact allergy for individuals sensitized to formaldehyde-related compounds
- Temporary tight feeling if the film is applied in thick layers
- Build-up on hair with heavy repeated use leading to dullness
If any uncomfortable reaction develops discontinue use and seek advice from a healthcare professional.
Comedogenic Rating
Rating: 0–1 (very low)
Oxymethylene/Melamine Copolymer forms a breathable film that sits on top of the skin rather than sinking into pores so it is unlikely to trap oil or debris. It is also oil free and non-waxy which keeps the chance of clogging pores minimal.
Because of this low score the ingredient is generally considered suitable for people who are prone to acne or breakouts.
As with any film former heavy layering in thick makeup or hair products could hold on to surface dirt over time. Regular cleansing removes any build-up and keeps skin clear.
Summary
Oxymethylene/Melamine Copolymer is a synthetic film former that dries into a clear flexible layer, helping makeup last longer, hair stay styled and skincare actives remain in place. By linking melamine units with formaldehyde it gains a strong network that resists water and smudging while still feeling light.
You will spot it most often in long-wear foundations, setting sprays and some peel-off masks but it is not yet as common as older polymers like PVP so its presence on ingredient lists is still fairly niche.
Current research shows it is low risk for irritation with no major health concerns when used as directed. Still, every skin is unique so perform a small patch test the first time you try a product that contains it.