Heat Wave in the Salon: Acetone, UV Gels and Hybrid Polishes in Summer

Thirty degrees outside, and inside a salon without air conditioning it can feel even hotter, because UV lamps, the e-file and other electrical equipment keep generating heat all day. In these conditions acetone and acrylic monomer evaporate faster, and the concentration of fumes in the air rises, even though you're working exactly the same way as you did in January. This is not just a comfort issue. It is a real occupational safety risk that needs to be managed differently in summer than the rest of the year.

Why heat changes the rules

Acetone, ethyl methacrylate and other volatile organic compounds (VOCs) evaporate faster the higher the ambient temperature. At 30 degrees, evaporation from an open container is several times more intense than at 20 degrees. In practice this means a higher concentration of fumes in the salon air, even if you use exactly the same amount of product as you would in winter.

• Acetone has a very low flash point, around minus 20 degrees Celsius. It is an extremely flammable substance, and in summer, with a container standing close to a window or a heat source, the risk increases.
• Acrylic monomer reacts to heat and light faster than in low temperatures, which can shorten its shelf life and change its consistency.
• UV gels and hybrid polishes should, according to most manufacturers, be stored at room temperature, usually 15 to 25 degrees. Above that range, the product may start to partially cure inside the bottle before it ever reaches a client's nail.

Ventilating the workstation: what actually works in summer

An open window in summer doesn't solve the problem the way you might expect. Warm air from outside exchanges more slowly than cold air, and on a hot, windless day the acetone fumes simply sit in the room.

• Local extraction at the workstation: an extractor placed close to the client's hand, right where the fumes are actually produced, works better than general room ventilation. This solution costs more than a fan, but it genuinely lowers the concentration of substances near the stylist's airways, and she sits at that station for eight hours a day.
• Air conditioning without filtration is not ventilation: an air conditioner cools the air, but in many models it recirculates it without exchanging it for fresh air. If air conditioning is your salon's only cooling source, without a separate mechanical ventilation system, fumes can circulate around the room together with the cool air.
• Gravity ventilation weakens in summer: the temperature difference between the inside and outside drives natural draught in ventilation ducts. In summer, when it's just as warm outside as inside, that natural draught practically disappears. If your salon relies solely on gravity ventilation, it works at its weakest exactly in July and August.

Storing chemical substances in summer

This is one point that both the Sanitary Inspectorate and the Labour Inspectorate check together: where and how you keep acetone, monomer and alcohol-based disinfectants.

1. Away from windows and sunlight. A container of acetone sitting on a sunny windowsill heats up well above room temperature. This speeds up evaporation and increases the risk of ignition on contact with an open flame or a spark, for example from a damaged socket.
2. A metal cabinet or a certified flammable-substance cabinet. For larger quantities (above a few litres) it is worth investing in a safety cabinet with an appropriate fire-resistance rating. For smaller quantities, a lockable cupboard away from heat sources is enough.
3. Seal containers tightly after each use. An open acetone container on a hot day evaporates noticeably faster than one with the lid closed. That's lost product, but also more fumes in the air that you and your client are breathing.
4. Keep the safety data sheet (SDS) within reach. Every chemical product used in the salon has a safety data sheet from the manufacturer or distributor, including a section on storage conditions and temperature. A Labour Inspectorate inspector may ask for it during a visit, and you should be able to show that you store the product according to the recommendations.

Occupational safety for a stylist on hot days

Exposure to chemical fumes combined with a hot room is a double burden on the body, not just a matter of working comfort.

• Breaks and hydration: on days when the room temperature is above 28 degrees, it is worth shortening continuous work time at the monomer station and increasing the number of short breaks. This is not a formal requirement for every salon, but a good safety practice, easy to write into an internal procedure.
• Rotating workstations: if you have more than one station, and one sits closer to a window or a heat source, rotate stylists between stations on hot days instead of keeping one person at the hottest point of the salon all day.
• Symptoms to watch for: headache, dizziness, irritation of the eyes and throat can indicate a fume concentration that is too high combined with the heat. If a stylist reports these symptoms regularly, that's a sign the ventilation at her station needs improving, not that she should simply get used to the conditions.

Frequently Asked Questions

Do I need air conditioning in the salon in summer?

Occupational safety regulations don't explicitly require air conditioning, but they do require maintaining an adequate temperature and air exchange at the workstation. If your salon regularly hits above 30 degrees in summer and gravity ventilation can't keep up, in practice that means you need some kind of cooling and ventilating solution, whether that's filtered air conditioning or mechanical ventilation.

Can I store acetone in a refrigerator to slow down evaporation?

We don't recommend this. A food refrigerator is not designed for storing flammable substances, and opening the door in a hot room causes temperature fluctuations anyway. A better solution is a lockable cabinet in a cooler, shaded part of the salon, away from heating equipment and direct sunlight.

What if a client complains about the smell of acetone on a hot day?

That's a sign that the concentration of fumes at that moment is noticeable, and therefore elevated. In the short term, opening a window on the other side of the room to create a cross-draught helps, along with moving the client further from the source of the smell. In the long term, it's worth checking whether the local extraction at the station is actually working and whether acetone containers are sealed tightly between clients.

Can I still use UV gel that has hardened in the bottle from the heat?

If the gel has partially cured or changed consistency (thickened, developed lumps), don't apply it to a client. The result on the nail will be uneven, and the risk of lifting is higher. It's also a sign that your storage spot for UV products is too warm in summer and worth moving to a cooler, shaded location.