A hyperbaric chamber is a specialized enclosure used to deliver Hyperbaric Oxygen Therapy (HBOT), a medical treatment where a patient breathes pure oxygen at increased atmospheric pressure. This therapy treats various conditions, including decompression sickness, severe anemia, and chronic wounds. The environment inside the chamber is highly controlled, and safety protocols are extremely strict regarding personal care items. The prohibition against wearing products like deodorant is a non-negotiable safety measure rooted in the physics of combustion, which is dramatically amplified in this unique setting.
Creating the Hazard: The High-Oxygen Environment
The safety mandate against deodorants and other flammables is directly linked to the physical conditions inside the hyperbaric chamber. Normal atmospheric pressure contains about 21% oxygen. During HBOT, the chamber is typically pressurized to between 1.5 and 3 times the normal atmospheric pressure (1.5 to 3 ATA).
Patients often breathe 100% pure oxygen, or the chamber itself is filled with pure oxygen. This combination of increased pressure and high oxygen concentration significantly raises the partial pressure of oxygen (\(\text{PO}_2\)), which measures how much oxygen is available to fuel a fire. In this oxygen-rich, high-pressure environment, the inherent flammability of nearly all materials changes drastically.
The ignition temperature, the point at which a substance will spontaneously catch fire, is dramatically lowered. A substance that might only smolder in room air can ignite explosively in the chamber. Once a fire starts, the pure oxygen causes it to burn with an intensity and speed that is almost impossible to extinguish, dictating strict safety rules for everything entering the chamber.
The Source of the Danger: Volatile Compounds in Personal Care Products
The prohibition against personal care products stems from their chemical composition, which introduces highly flammable “fuel” into the high-oxygen environment. Many products, including deodorants, perfumes, and makeup, contain Volatile Organic Compounds (VOCs), alcohols, petroleum-based ingredients, and propellants. These substances are designed to evaporate easily, making them prone to forming flammable vapors.
Aerosol deodorants often contain flammable propellants like propane or butane, and many stick or roll-on types use high concentrations of alcohol as a solvent. When these flammable vapors are released and concentrated in the high-pressure, pure-oxygen atmosphere, they become explosive fuels. Even residual films of oil or alcohol-based lotions left on the skin can off-gas and create a dangerous vapor cloud.
The presence of these hydrocarbon-based compounds provides the “fuel” component of the fire triangle. When combined with the abundant “oxidizer” (pure oxygen) and a tiny “ignition source” (like static electricity), this combination creates a catastrophe. Eliminating the chemical fuel source from the patient’s body is necessary to prevent a fire.
Comprehensive Safety Protocols and Patient Preparation
The rigorous safety protocols include a thorough patient preparation process that extends beyond avoiding deodorant. Before treatment, patients must shower or thoroughly cleanse their skin to remove all traces of residual personal care products, including oils, makeup, and creams. This mandatory cleaning ensures that no volatile or flammable residues remain on the skin or hair.
Patients must also change into a 100% cotton garment provided by the facility. Synthetic fabrics like nylon and polyester can easily generate a static electricity spark—a potential ignition source—in the high-oxygen environment. Other prohibited items include petroleum jelly, hair spray, electronics with batteries, and any metal items that could create a spark or friction.
These precautions are standard medical procedure designed to eliminate all three components of the fire triangle: fuel, oxidizer, and ignition source. By strictly controlling what enters the chamber, medical staff ensure the safety of the patient and personnel.