Material
Plastic food container
An easy material with awkward details: lid seals, threads and grooves hold residue that washing the box itself never reaches.
- SurfaceNon porous
- WashingSpot only
- Colour run riskLow
- Reviewed7 September 2026
What plastic food container can and cannot take
- Heat Avoid
- Water and soaking Tolerates it
- Acids, including vinegar Tolerates it
- Strong alkalis Tolerates it
- Solvents Avoid
- Chlorine bleach Use with care
- Abrasives Avoid
General rules for plastic food container
Take it apart. Almost every food container has a removable silicone seal in the lid, and that seal is where the smell lives.
Wash everything separately in warm soapy water, including the groove the seal sits in, and dry it all before putting it back together.
For a persistent smell, a bicarbonate of soda paste left in the container for an hour is the standard answer and it works.
Check the label
The material is easy and the details are not. Lids, seals and threads hold residue where a cloth never reaches, and a container that smells after washing almost always has milk residue in the lid seal rather than in the box.
Stains on plastic food container
- Baby sick Take the lid apart before washing anything. Almost every food container has a removable silicone seal, and th...
- Blood Blot first, then use cold water and a tiny amount of compatible detergent. Work from the edge, rinse or blot...
- Body oil Lift free oil from plastic food container, then clean a small area with a maker-approved mild detergent solut...
- Breast milk Blot the spill, identify the finish and use a controlled cold clean only where permitted. Where the maker per...
- Bronzer Lift loose bronzer from plastic food container before it is rubbed in. Blot cream bronzer, follow the materia...
- Coffee Wipe coffee off plastic food container promptly with a soft cloth. Check the finish and maker care rules firs...
- Concealer Lift thick concealer from Plastic Food Container, blot without rubbing, then use a very small amount of dilut...
- Cooking grease Lift and blot cooking grease from Plastic Food Container, then use a small amount of diluted washing-up liqui...
- Deodorant Lift loose deodorant from plastic food container with a dry white cloth, then wipe the remaining film with co...
- Hair dye Blot hair dye from Plastic Food Container, test the mildest compatible cool detergent route, clean inwards, r...
- Lipstick Lift lipstick from Plastic Food Container with a blunt edge, blot without rubbing, then use a very small amou...
- Motor oil Blot motor oil from Plastic Food Container, absorb as much as possible, then use a small amount of diluted wa...
- Nail polish Lift free polish gently if the face permits contact. A maker-approved mild damp wipe can clear loose residue,...
- Period blood Lift any tissue with a spoon edge, then blot. Use cold water and a tiny amount of compatible detergent for th...
- Pet urine Blot until nearly dry, then use only the cool-water quantity plastic food container can tolerate. Use a label...
- Tomato sauce Lift tomato sauce from Plastic Food Container, then wipe or blot inwards with a tested cool detergent solutio...
A plastic food container is a moulded box, a lid and usually a silicone gasket.
The box is trivial
Non porous, dishwasher safe in most cases, and washed clean with detergent.
The seal is not
The silicone gasket in a lid pulls out, and the groove behind it collects liquid that never dries. That is where a container that smells clean but smells of old milk is holding it.
Milk fat yellows plastic
Over time, milk residue oxidises and leaves a yellow tinge, particularly on polypropylene. An oxygen soak lifts it; chlorine bleach makes it worse over repeated use.
Heat before cleaning is the trap
A dishwasher cycle on a container with milk residue in it bakes the residue into the surface texture.
Sources
What we checked and when. Where a manufacturer instruction disagrees with anything here, follow the manufacturer.
-
Melamine dinnerware and staining, G.E.T.
manufacturer
Melamine manufacturer guidance that staining is caused by food left to dry on the surface and by protein and hard water minerals building up, that an oxygen releasing soak or an overnight soak in warm water with dishwashing granules removes the stains, that a non abrasive pad is used afterwards, and that bleach, green scouring pads, steel wool and metal scourers must not be used because they dull and scratch the surface.
Checked 7 September 2026
-
Wooden chopping boards, Food Safety Authority of Ireland
authority
Food safety authority guidance that a chopping board surface must be smooth, washable, corrosion resistant and non toxic, that deeply scored boards are harder to clean and can harbour harmful microorganisms so should be re-planed or replaced, and that boards are scrubbed with hot water and detergent using a brush, rinsed, treated with a food grade disinfectant, rinsed again and dried completely before storage.
Checked 7 September 2026
-
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