How to dispose of old nail polish

Every polish drawer contains a few bottles that have gone thick, separated or out of favour. Throwing them away raises a question that three countries answer three different ways, because a nail polish bottle is glass with a flammable liquid inside, and each waste system weighs those two facts differently.

Why polish is treated with care, what the Dutch, British and American rules say, whether small amounts can be dried, what happens to the bottle, cap and brush, and a step-by-step for clearing a drawer, with the waste authorities' own words as the sources.

Why is old nail polish treated as hazardous waste?

Nail polish is about 70 percent solvent, mainly ethyl acetate and butyl acetate, with nitrocellulose, plasticisers and pigments dissolved in it (Earth911). The solvents are flammable, and nitrocellulose is itself a combustible material. Liquid polish in a bin lorry is a small fire risk, and poured down a sink it reaches water treatment that was not built for solvents.

The United States Environmental Protection Agency defines household hazardous waste as leftover household products that can catch fire, react or explode under certain circumstances, or that are corrosive or toxic, and advises never pouring them down the drain, on the ground or into storm sewers, and keeping them in their original labelled containers (US EPA). Liquid polish and remover fit that definition on the first count, flammability.

Dried polish is a different material. Once the solvent has evaporated, what remains is a solid nitrocellulose film that is no longer a liquid fire hazard, which is why the Dutch guidance accepts residue in a bottle bound for glass recycling.

Where does nail polish go in the Netherlands?

Milieu Centraal, the Dutch government-funded consumer body on environment, answers through its Afvalscheidingswijzer: nail polish goes in the glass bin. A glass bottle may be disposed of with leftover polish still inside, because the glass recycler can cope and the small amounts of polish and other contamination burn off in the melting process. The brush can be put in residual waste as a favour to the recycler, and polish must not be rinsed down the sink (Afvalscheidingswijzer).

Milieu Centraal's list of small chemical waste (klein chemisch afval, KCA) puts nail polish and nail polish remover in the column of products that are not KCA (Milieu Centraal). That is the national guidance. Municipal waste companies sometimes differ. Rd4, which serves part of Limburg, lists nail polish under residual waste and nail polish remover under KCA: an empty glass remover bottle in the glass bin, an empty plastic one in the plastic and packaging bag, and any bottle with remnants at the KCA point of the recycling centre (Rd4).

The practical order for a Dutch reader: check the afvalapp of your own gemeente; failing a local rule, follow Milieu Centraal and use the glass bin; and treat remover with more caution than polish, because it is a bottle of pure solvent.

Where does it go in the United Kingdom?

The North London Waste Authority states that nail and gel polish are not recyclable, so the best thing to do is use them up, and that polish is highly flammable and should not go in the household rubbish bin. It can be disposed of free through the local hazardous waste service, usually as part of a booking with other household chemicals such as oil-based paint or weedkiller (NLWA). The same authority says remover is hazardous waste that should not be poured down the sink or put in the bin (NLWA).

Bottles are the sticking point in Britain. NLWA says nail varnish bottles cannot be recycled even though they are glass, because of the varnish inside. Some brands take their own bottles back: Nails Inc, Mavala, Barry M and Kure Bazaar accept cleaned glass bottles, and the professional distributor Louella Belle runs a return scheme for salons (Get the Gloss). Rules differ between councils, so check your own council's page.

Where does it go in the United States?

The EPA classifies nail polish as household hazardous waste and directs residents to local collection programmes, permanent facilities or collection days, which can be found through the Earth911 database or the local environmental agency (US EPA). Zero Waste Sonoma in California is typical: polish goes to the county household hazardous waste facility, and the trash, the recycling bin and the drain are excluded (Zero Waste Sonoma).

Some brands run mail-back programmes for empties in which bottles, caps and brushes are recovered separately (Earth911).

Can you dry out small amounts before throwing them away?

Drying turns a flammable liquid into a solid film, and the American guidance applies the idea to remover-soaked cotton pads: let them dry out completely in a well-ventilated area before throwing them away (Earth911). The same logic covers a few millilitres at the bottom of a bottle. With the cap off in a ventilated spot away from heat and flame, the solvent leaves over a few days and the residue hardens.

Two limits apply. Drying a half-full bottle releases a great deal of solvent into the room and takes weeks, so it is not a substitute for a hazardous waste drop-off. And a dried bottle still goes where the local rule says: the Dutch glass bin already accepts wet residue, and a British council still keeps the bottle out of kerbside recycling.

Can the bottle, cap and brush be recycled?

The bottle is glass, the cap is plastic, the brush is plastic with nylon bristles, and there are usually two steel mixing balls inside. Only the glass has a mainstream recycling route, and only where the recycler accepts residue. TerraCycle's Sam Angel puts the general rule for recyclers this way: containers and packaging must be completely emptied of their contents to avoid contamination. The same source notes that a polish bottle is usually thrown away because the polish has gone too dry to use, and rarely because it is empty (Get the Gloss).

Cleaning a bottle for recycling means removing the brush and cap, soaking the bottle in acetone, wiping it out and letting it dry. For one or two bottles that is a small job; for a drawer it consumes more remover than the glass is worth. Brand take-back schemes exist because they solve the cleaning problem at scale.

How to avoid throwing polish away at all

Most polish is discarded because it thickened, not because it ran out. Polish thickens when solvent escapes past a cap that was left loose or crusted with dried polish. Wiping the neck of the bottle before closing it, storing bottles upright, cool and out of sunlight, and keeping the cap tight between coats slows the loss. A polish that has thickened can be restored with a few drops of nail polish thinner, which replaces the lost solvent; remover does not do the same job, because acetone breaks the film former down.

Clearing a polish drawer, step by step

You will need: your local waste guide open on a phone, a box for bottles to keep, a box for bottles to go, nail polish thinner, remover, cotton pads, a small bag for brushes and caps, and a ventilated table.

1. Sort. Keep anything that still pours or can be thinned. Set aside anything solid, separated beyond stirring or more than a few years old.
2. Thin the thick ones. Add thinner a few drops at a time, cap and roll the bottle between your palms, and repeat until the polish pours.
3. Look up your rule. In the Netherlands, check your gemeente's afvalapp, then Milieu Centraal. In Britain, check your council's household waste recycling centre page. In the United States, search the Earth911 database for the nearest household hazardous waste collection.
4. Prepare bottles for the glass bin where that is the rule. Remove the brush and put it in residual waste; leave the cap on or off as your municipality prefers.
5. Prepare bottles for hazardous waste where that is the rule: capped, upright, in their original labelled form.
6. Deal with remover separately. A bottle with remnants is hazardous waste in Britain and the United States and at some Dutch municipalities; pads go in residual waste once fully dry.
7. Keep everything away from the sink, the toilet and the garden.

“containers and packaging must be completely emptied of their contents to avoid contamination”

Sam Angel, TerraCycle, quoted by Get the Gloss