2.3 Prohibited Substances, Chemical Storage & Facility Safety
Key Takeaways
Minn. Stat. 155A.355 bans methyl methacrylate (MMA) liquid monomer and fumigants such as formalin tablets or liquids from cosmetology services.
Minn. R. 2105.0377 also bans UV sterilizers or light boxes, roll-on wax (except single-use cartridges), drills not made for human use, and storing customers' tools.
OSHA regulates workplace safety and safety data sheets, the EPA registers disinfectants, and the FDA regulates cosmetics and sterilizing devices.
Salons must keep a safety data sheet for every hazardous product available to all personnel and train licensees on those hazards at least every 12 months.
Products removed from a container must never be returned, and any product not in its original container must be legibly labeled (Minn. R. 2105.0375, subp. 7).
Prohibited Substances, Chemical Storage & Facility Safety
Nail services depend on reactive chemicals: methacrylate monomers, cyanoacrylate adhesives, light-cured oligomers, solvents, and disinfectants. Minnesota bans some of them outright, and federal agencies regulate the rest. "Prohibited materials" and "chemical labeling and storage" are listed theory sub-topics, and "salon prohibitions" is a state-exam topic.
1. Minnesota's Prohibited Substances
Minn. Stat. § 155A.355, subd. 3: licensees must not use, in performing cosmetology services,
- methyl methacrylate liquid monomers (MMA); and
- fumigants, including but not limited to formalin tablets or formalin liquids.
Minn. R. 2105.0377, item A repeats the list: MMA liquid monomers, formalin tablets, formalin liquids, and other fumigants are prohibited substances in salons. Formalin "dry cabinet" fumigation was an old practice for storing tools. It releases formaldehyde, a carcinogen and respiratory irritant, and it is not an approved disinfection method.
Why MMA Is Banned
In the 1970s the U.S. Food and Drug Administration used court actions to remove products containing 100% liquid MMA monomer from the market after injury complaints. The FDA has not issued a formal ban, but many states, including Minnesota, prohibit MMA monomer in salons. The problems:
- Allergic sensitization: MMA is a strong skin sensitizer that can cause contact dermatitis around the nail folds.
- Rigidity: cured MMA is extremely hard and inflexible. When the nail is jammed, the enhancement does not break, and the natural plate can tear from the nail bed.
- Poor adhesion: MMA does not bond well to keratin, so users over-file the plate to make it grip.
- Removal: MMA resists acetone and is often pried or drilled off, damaging the plate.
MMA vs. EMA
| Clue | MMA liquid monomer (prohibited) | EMA-based monomer (legal) |
|---|---|---|
| Odor | Very strong, sharp, fruity smell | Noticeable but milder acrylic odor |
| Cured product | Very hard and brittle; does not flex | Tougher and more flexible |
| Under impact | Nail plate may tear from the bed | Enhancement cracks or breaks first |
| Acetone soak | Softens very slowly, turns gummy | Softens and can be removed in a normal soak |
| Nail preparation | Aggressive filing needed to make it stick | Light removal of shine plus primer |
| Packaging | Often unlabeled bulk containers at low prices | Labeled professional products with SDS |
Exam clue: an enhancement that is rock-hard, will not soak off, came from an unlabeled jug, and required heavy filing points to MMA.
2. Other Salon Prohibitions (Minn. R. 2105.0377)
| Item | Rule |
|---|---|
| A | MMA liquid monomers, formalin tablets, formalin liquids, and other fumigants are prohibited |
| B | Razor-type callus shavers, credo blades, rasps, graters, and other skin-cutting implements are prohibited and must not be present |
| C | Roll-on wax is prohibited. Single-use roll-on cartridges are acceptable if discarded after the service; a cartridge in a heater must have an intact seal |
| D | UV sterilizers or light boxes are not acceptable infection control devices and must not be present; UV lamps that dry or cure nail products are allowed |
| E | Autoclave packaging of tools is prohibited unless an autoclave is actually used in compliance with the sterilization rule |
| F | Electric or battery-operated files or drills not specifically manufactured for use on humans are prohibited |
| G | Customer-supplied tools may be used only after they are cleaned and then disinfected or sterilized; customer-supplied prohibited tools must be removed from the premises; customer-supplied single-use items must be new |
| H | Salons must not store a customer's tools or implements |
| I | Only single-use sterile lancets may be used (and nail technicians may not penetrate skin at all) |
Live fish, leeches, snails, and other living creatures may not be used in any cosmetic service, which rules out "fish pedicures" (Minn. R. 2105.0375, subp. 7, item I).
3. Safety Agencies: Who Regulates What
| Agency | Role in the nail salon |
|---|---|
| OSHA (federal) and Minnesota OSHA (MNOSHA, the state plan) | Worker safety: the Hazard Communication Standard (29 CFR 1910.1200) with labels, safety data sheets, and training; the Bloodborne Pathogens Standard (29 CFR 1910.1030); PPE; exposure limits; eyewash where corrosives are used |
| EPA | Registers disinfectants (look for an EPA registration number). Minnesota requires hospital-level, EPA-registered products labeled bactericidal, virucidal, and fungicidal |
| FDA | Regulates cosmetics such as polish, removers, and lotions for safety and labeling, and medical devices. Minnesota requires autoclaves and other sterilizers to be FDA-registered and listed (Minn. R. 2105.0375, subp. 4a). The FDA took the 1970s court actions against 100% MMA products |
| Minnesota Board of Cosmetology | Licenses practitioners, salons, and schools; writes and enforces the chapter 2105 salon and infection-control rules |
4. Labeling, Storage, and Dispensing
- Any product not in its original container must be legibly labeled (Minn. R. 2105.0375, subp. 7, item D). A cleaning agent in a secondary container needs a label with its name and use directions (subp. 3), and disinfectant solutions need the disinfectant name and any dilution (subp. 4).
- Fluids, semifluids, creams, waxes, and powders must be kept in clean, covered containers and dispensed so the unused supply cannot be contaminated. Use disposable or disinfected spatulas or applicators, never fingers, and do not store spatulas in the container (subp. 7, item C).
- Product removed from a container is never returned; use it or discard it. Container exteriors are wiped with a disinfectant wipe at the end of the day.
- For monomer, pour only what the service needs into a clean dappen dish, never dip a brush into the bottle, and never pour leftovers back. Wipe excess into a paper towel and discard it in a closed waste container. Many texts recommend a metal container with a self-closing lid for monomer- and solvent-soaked waste.
- Keep monomers, primers, and adhesives tightly capped and away from heat, flame, sunlight, and curing lamps. Keep flammables such as acetone in closed containers and bulk supplies in a flammable-storage cabinet.
- In restrooms, hazardous cleaning agents, chemicals, and medications must be in locked cabinets (Minn. R. 2105.0360, subp. 6a).
5. Safety Data Sheets and Hazard Training (Minn. R. 2105.0370, item B)
The salon must comply with the federal Hazard Communication Standard and:
- make a paper or electronic safety data sheet (SDS) for each product containing hazardous chemicals available to all salon personnel and all licensees at all times; and
- at least once every 12 months, inform all licensees of the potential health effects of those products and the protective measures to use, including best work practices, spill cleanup, emergency procedures, and personal protective equipment.
SDSs follow a standard 16-section format. The sections technicians use most are 2 (hazards), 4 (first-aid measures), 7 (handling and storage), 8 (exposure controls and PPE), and 9 (physical properties such as flash point). An SDS locked in an owner's office or on a password-protected device staff cannot open is not available "at all times."
6. First Aid, Eyewash, and Spills
- First aid kit: readily accessible and meeting ANSI Z308.1-2015 or the most recent version (Minn. R. 2105.0370, item A).
- Eyewash: OSHA requires suitable facilities for quick drenching or flushing of the eyes where corrosive materials are used. Acid primers are corrosive, so a plumbed or self-contained eyewash is expected. Flush for at least 15 minutes and seek medical care, bringing the SDS.
- Solvent or monomer spill: remove ignition sources (unplug drills and lamps; no flames), ventilate, absorb with an absorbent the SDS lists as compatible, bag and seal the waste, and dispose of it according to the SDS and local rules.
Why is methyl methacrylate (MMA) liquid monomer prohibited in Minnesota salons?
Its odor is too weak for technicians to judge proper liquid-to-powder ratios
It dissolves so quickly in acetone that enhancements cannot last two weeks
It cures into an extremely rigid enhancement that can tear the natural nail from the bed, and it is a strong skin sensitizer
It makes the natural nail so flexible that enhancements crack as they cure
During an acetone soak-off, which observation most strongly suggests the client's enhancements were made with MMA rather than an EMA-based monomer?
The product stays hard and turns gummy instead of softening after a normal soak
The product softens and lifts away easily with a wooden pusher
The product dissolves completely in under one minute
The product turns bright blue and flakes into powder
Under Minn. R. 2105.0370, what must a salon do about safety data sheets (SDS)?
Keep SDSs only for retail products sold to customers
Keep SDSs in the owner's locked office and provide them within 10 days of an employee's request
Keep SDSs only for products containing formaldehyde
Make an SDS for every product with hazardous chemicals available to all personnel at all times and train licensees on the hazards at least every 12 months
Which item is prohibited from even being present in a Minnesota salon under Minn. R. 2105.0377?
An LED lamp used to cure gel polish
A UV sterilizer cabinet used to hold implements
An autoclave with monthly independent spore tests
A jar of EPA-registered hospital disinfectant labeled with its dilution
What is the correct way to dispense liquid monomer for an acrylic service under Minnesota's product-handling rules?
Dip the brush directly into the manufacturer's bottle so the monomer stays fresh
Pour leftover monomer back into the bottle at the end of the service
Pour only the needed amount into a clean dappen dish and discard, never return, what is left
Dilute leftovers with acetone and store them in an open cup for the next client
Sections you finish are checked off in the contents.