The Hidden Hazards in Maintenance Closets

The most dangerous rooms in America are often the ones marked SUPPLIES. Q&As in this blog include:

1. Why are we talking about maintenance closets?
2. Isn’t this a tad hypervigilant? After all, it’s a supply closet, not a Superfund site.
3. Is a can of spray lubricant really a threat to civilization?
4. Isn’t this a fire-code problem—not a health one?
5. How are adhesives problematic?
6. What about degreasers?
7. Is this just about stuff nobody throws away?
8. Isn’t paint basically inert once it’s dry?
9. Why are old mercury thermostats a problem?
10. Is all this expensive to fix?
11. Where can you get expert advice and help dealing with the hidden hazards in maintenance closets?

Why are we talking about maintenance closets?

Because nobody else will. Fires get press. Chemical spills get press. But the maintenance closet? That dim, cinderblock cubicle behind the boiler room where three generations of custodians have been quietly stacking cans since the Ford administration? It gets nothing. Yet, it’s the most unregulated square footage in America. And it’s sitting in your building right now.

Isn’t this a tad hypervigilant? After all, it’s a supply closet, not a Superfund site.

Give it time. A Superfund site is just a supply closet that nobody cleaned out for forty years. The ingredients are already there: aerosols, solvents, adhesives, degreasers, dead paint cans, and in older buildings, a mercury thermostat or two.

None of this is exotic, and that’s exactly the point. A workplace hazard rarely announces itself. It just accumulates on a shelf, until somebody asks what’s in the brown bottle with no label.

Is a can of spray lubricant really a threat to civilization?

No single can is. But maintenance closets don’t contain single cans; they contain populations of cans, most of them under pressure, many decades past any sell-by date, stored in a room that in summer can get warmer than a parked car.

Aerosol propellants are flammable hydrocarbons, often butane, propane, or isobutane, sitting a few feet from an electrical panel, a water heater, or—in one memorable case—a space heater that somebody plugged in because the closet also served as an impromptu break room. Heat + pressurized flammable gas + ignition source is not a hypothetical hazard. It’s arithmetic.

Isn’t this a fire-code problem—not a health one?

It’s both, which is what makes maintenance closets interesting rather than merely annoying.

The fire-code problem is the dramatic one. The health problem is the slow one. And slow problems are the ones Americans are worst at taking seriously. Consider:

A closet full of solvents will surrender gasses continuously into the ambient air. (E.g., mineral spirits, acetone, toluene-based adhesive removers, etc.) They do this mischief even if sealed in their cans. And ventilation in these storage rooms is usually just an afterthought. Like, “There’s a door. Doesn’t that count?”

The upshot: Custodial staff and others go in and out of that atmosphere daily, often without being told precisely what they’re haplessly breathing.

How are adhesives problematic?

Depends on the glue. Contact cement and construction adhesives are frequently solvent based. Solvent-based means volatile organic compounds, the same VOC family responsible for the “new car smell” everyone finds charming in small doses and toxic in large ones.

A tube of construction adhesive is harmless. A shelf of forty tubes in an unventilated room, some of them split at the seam because nobody rotates stock, is a different proposition. This is the general lesson of the maintenance closet: quantity converts a nuisance into a hazard. Chemistry doesn’t care that the room is small.

What about degreasers?

Dangerous. And for a reason people find counterintuitive: the older the degreaser, the more likely it contains something that’s been restricted or banned outright. E.g., chlorinated solvents like trichloroethylene, perchloroethylene, or methylene chloride. All of these have well-documented links to organ damage and (in some cases) cancer.

Also, methylene chloride in the form of paint stripper was specifically restricted in 2019 by the EPA (for consumer use) after it proved fatal to people who used it in enclosed spaces. And maintenance closets are the epitome of enclosed spaces. If your facility has a degreaser can with a Nixon-era design aesthetic, it’s not a Watergate memento. It’s a liability.

Is this just about stuff nobody throws away?

Unglamorously, that’s the bulk of the story. Institutions are excellent at acquiring chemicals and terrible at disposing of them, because disposal requires someone to make a decision, fill out paperwork, and possibly pay a hazardous waste hauler.

Conversely, acquisition just requires a purchase order. The path of least resistance is always “put it on the shelf.” So, the shelf becomes a geological record. You can practically carbon-date a maintenance closet by the label design on the bleach.

Isn’t paint basically inert once it’s dry?

Latex paint is generally safe once it’s fully dry and cured. The water and low-level volatile organic compounds (VOCs) evaporate during the drying process, leaving behind an inert, non-toxic plastic or rubbery film that locks in the pigments. If your business calls for an inert, non-toxic plastic or rubbery film, by all means keep the stuff. But most people should just put it into the regular waste stream (see source).

On the other hand, cans that are not dry—meaning oil-based paint stored for years—aren’t only flammable; they emit noxious fumes that concentrate in a closed room.

And then there’s the problem that actually lands people into courtrooms: lead-based paint.

Paint manufactured before 1978 might contain lead. And buildings operating previous to that date frequently have exactly such cans of lead-based paint still hanging around, because (per Q.7) nobody ever throws anything away.

A lead paint can from 1974 isn’t a museum piece. It’s a toxic waste with a nostalgic label. And if it’s ever cracked open for a touch-up job, exposing employees and customers to lead in the process, OSHA won’t be sending a strongly worded letter. They’ll be sending an inspector with a clipboard and litigious attitude.

Why are old mercury thermostats a problem?

Mercury thermostats were standard equipment for decades and were phased out mostly in the 2000s as programmable and digital models took over, with several states eventually banning the sale of mercury thermostats outright. But “banned from sale” doesn’t equate to “removed from service.”

Old units get pulled during renovations and set on a shelf “in case we need it.” Thereby, the glass ampule containing several grams of liquid mercury sits waiting for someone to drop it. Menacingly so, because mercury vapor is an odorless neurotoxin, making this spill job not one for a broom and a dustpan. It typically requires specialized vacuum equipment and—depending on quantity—a hazmat response.

Is all this expensive to fix?

Compared to the unholy trinity of litigation, a workers’ comp claim, and an EPA fine—not really. The fix itself isn’t expensive. It’s just tedious, which in institutional life amounts to the same barrier. You have to inventory the closet, actually read the labels, separate anything flammable from anything that generates heat, and ventilate the room properly.

Afterward, you need to dispose of whatever’s unlabeled or unidentifiable using a licensed hazardous waste hauler rather than sticking it in that dumpster behind the maintenance garage, treating any thermostat, fluorescent ballast, or other mercury-containing device as universal waste requiring special handling.

Where can you get expert advice and help dealing with the hidden hazards in maintenance closets?

For expert help clearing out the hidden hazards in your maintenance closets, turn to Hazardous Waste Experts. Our trained specialists will identify, categorize, and legally dispose of your aerosols, solvents, adhesives, degreasers, ancient paint, and rogue mercury thermostats—no shoebox archaeology required—ensuring full regulatory compliance.

From onsite audits to proper disposal documentation, Hazardous Waste Experts takes the guesswork (and liability) off your hands, so your facility stays safe, compliant, and audit ready year-round.

Contact us today.