Fibre encyclopedia
Modacrylic
Also called modacrylic · modakrilik · MAC
Acrylic with the chain modified, which changes how it behaves near heat. It goes into fake fur and into workwear that has to pass a flame test.
Class
Synthetic
Comes from
From oil or gas
Where it comes from
Labelling rules use the name modacrylic when acrylonitrile makes up between 50 and 85 per cent of the mass, with a second monomer making up the rest. That second monomer is what separates it from acrylic.
How it feels to wear
Air
Little air moves through the fibre
Water
Water stays on the surface
Heat
Holds body heat
Stretch
A little stretch of its own
Wear
Holds up to ordinary rubbing
Modacrylic is made into long dense pile, which is why it is the usual fibre in fake fur. It holds almost no water and shrinks under heat at a lower temperature than acrylic, so a hot wash changes the pile permanently. Where it is used in protective clothing, the flame testing is done on the finished cloth, not on the fibre.
Care
- Wash cool or not at all; brush the pile instead.
- No heat anywhere: no dryer, no iron, no steam.
Heat is the single thing that changes modacrylic pile, and the change does not reverse.
End of life
Recycling route
No route running at scale
There is no sorted route for modacrylic. Sorting lines read it as acrylic, and the pile construction keeps it out of shredding in any case.
In a blend
Fake fur is usually a modacrylic pile on a polyester or cotton backing, bonded rather than spun, and the layers do not separate.
Skin notes
Mechanical
Long pile sheds cut fibre at the surface, which is what settles on the clothing worn under it.
Chemical
The second monomer and the dye system are not named on the label.
If your skin reacts to a garment, a dermatologist and patch testing are what can answer it. A label cannot, and neither can this page.
What the label cannot tell you
The label says modacrylic. It does not say which comonomer was used, and the comonomer is the whole difference between this fibre and acrylic.
Sources
- Regulation (EU) No 1007/2011 on textile fibre names and related labelling, Annex I. Checked 22 August 2026
- ISO 2076:2021, Textiles, man-made fibres, generic names. Checked 22 August 2026
Written from primary sources and in our own words. Where a figure could not be traced to a source anyone can open, it is not printed here.
Read the label you are holding
The scan surface reads one care label and names which questions it answers and which it leaves out. A passport says for one specific piece what a label cannot: the composition with its percentages, where the cloth came from, who worked on it, how to repair it and where it goes next.