(WHTM) — If you have a very tough mess to clean up, you may use many cleaning items at once. But, there are some chemicals that should never be mixed or used together.

Mixing chemicals can lead to large vapor clouds and even explosions if not used correctly. This can lead to health issues, injuries, or even death.

In 2019, an employee at a Massachusetts Buffalo Wild Wings died after inhaling fumes created when two chemicals were mixed together by another employee to clean the restaurant’s kitchen floor.

Here are a few household products that should never be mixed together, according to Good Housekeeping.

Bleach and rubbing alcohol

The only thing you should ever mix with bleach is plain water. Mixing bleach with rubbing alcohol creates chloroform, a colorless strong-smelling liquid that evaporates into gas. The result is highly toxic and can cause damage to the eyes, lungs, and even your liver.

Bleach and ammonia

Many window cleaners, such as Windex, contain ammonia. If mixed with bleach, it produces a toxic gas called chloramine. Fumes from this gas can cause sinus congestion, choking, shortness of breath, and coughing. In some cases, it can even cause chest pain.

Bleach and vinegar

As stated above, you should never mix bleach with anything but plain water. But, if you mix it with vinegar, it can create chlorine bleach, which contains sodium hypochlorite. This can cause nausea, vomiting dizziness and even can be fatal if ingested in high volumes.

Two different types of drain cleaner

Carolyn Forte, who is the director of the Good Housekeeping Institute of Cleaning, states that people should never mix two different drain cleaners together, or even use them one after the other. Each drain cleaner may contain different chemical formulas and can even explode if they are combined. Use only one type of cleaner. If that one product doesn’t work, call a plumber instead.

Hydrogen peroxide and vinegar

Some may have heard that you should spray countertops with alternating mists of these two items, but you should never combine them in the same container. These products together create peracetic acid, a corrosive liquid that can be very irritating to the eyes and can cause burns on the skin.