The Stain Library

Material

Nylon

A smooth synthetic that washes easily in cool water but yellows permanently with chlorine bleach and with heat.

  • SurfaceNon porous
  • WashingMachine
  • Colour run riskMedium
  • Reviewed7 September 2026

What nylon can and cannot take

  • Heat Avoid
  • Water and soaking Tolerates it
  • Acids, including vinegar Use with care
  • Strong alkalis Use with care
  • Solvents Use with care
  • Chlorine bleach Avoid
  • Abrasives Use with care

Always test on a hidden area first and let it dry before you treat the visible mark.

General rules for nylon

Cold rinse and a biological soak work well on nylon, because milk sits on the surface rather than in the fibre.

What nylon will not tolerate is chlorine bleach, which turns it a yellow that cannot be reversed, or heat, which both sets the stain and can melt the fibre.

Wash it cool, on a gentle cycle, and air dry it. Manufacturers are specific that repeated hot machine washing dulls nylon and takes the shape out of it.

Check the label

Nylon yellows. Chlorine bleach yellows it permanently and so does heat, and manufacturers warn that repeated machine washing causes discolouration and loss of shape. Cool water on a gentle cycle, and never bleach, are the two things that matter.

Stains on nylon

Nylon was the first synthetic fibre and it has one distinctive fault.

It yellows

Chlorine bleach turns nylon yellow and there is no way back from it. Heat does the same thing more slowly. That means the two things people reach for when a white item is stained are precisely the two things that ruin it.

It does not absorb the stain

Milk sits on the fibre rather than in it, so a cool soak with enzymes gets under it easily. Nylon is a good candidate for a long soak.

Heat is a hard limit

Nylon melts at a lower temperature than polyester, which is why an iron left on nylon for a moment leaves a permanent shiny mark.

It loses shape

Manufacturers warn that repeated machine washing causes loss of shape as well as discolouration, which is why the advice here is cool, gentle and not often.

Sources

What we checked and when. Where a manufacturer instruction disagrees with anything here, follow the manufacturer.

  1. How to clean polyester and synthetics, Woolite manufacturer

    Detergent manufacturer guidance that polyester is washed, dried and ironed at low to medium heat only because excessive heat can melt the fibres, that air drying is preferred to machine drying, that nylon is washed in cool water on a gentle cycle because repeated machine washing causes discolouration and loss of shape, and that acrylic knits are laid flat or dried at low temperature to keep their shape.

    Checked 7 September 2026

  2. How to remove baby formula stains, Purex Stain Lab manufacturer

    Manufacturer guidance identifying breast milk, formula and baby spit-up as protein stains, explaining the role of enzymes, and warning that the mark should be checked before any drying heat because heat sets what remains.

    Checked 7 September 2026

  3. A guide to newborn laundry, American Cleaning Institute trade body

    Cleaning trade body guide to pre-treat breast milk, formula or spit-up with an enzyme stain remover, soak fresh marks for at least 30 minutes and older marks for several hours, launder, and keep stained items out of the dryer until the mark has gone.

    Checked 7 September 2026