Propane (liquefied petroleum gas or LPG) is a common fuel stored as a liquid under pressure at a low temperature. When liquid propane contacts the skin, it immediately expands and turns into a gas. This rapid phase change creates severe danger, making accidental skin exposure a medical emergency requiring immediate action.
Why Liquid Propane Causes Rapid Freezing
Severe tissue damage from liquid propane results from a physical process called the latent heat of vaporization. Propane has an extremely low boiling point, around -44°F (-42°C), meaning it transitions from a liquid to a gas far below the freezing point of water. As the liquid propane touches the warmer skin, it rapidly vaporizes, requiring a massive amount of heat energy to complete the phase change.
This vaporization aggressively draws heat away from the skin and underlying tissues, causing localized freezing within seconds. The resulting injury is similar to severe frostbite, often called a cold burn or cryogenic injury. Initial symptoms include immediate numbness and a lack of pain because the cold rapidly damages nerve endings. The skin may quickly take on a waxy, white, or yellow appearance as the tissue freezes. This damage can be deceptively deep, often causing more extensive injury to underlying structures than the surface appearance suggests.
Immediate Steps for Skin Exposure
The first step is to stop the exposure by moving away from the source of the liquid propane. Once the area is safe, assess the clothing covering the injured site. If clothing is frozen to the skin, it must not be pulled away. Instead, carefully cut away any unfrozen clothing surrounding the area to prevent further trauma.
The priority for first aid is to rewarm the frozen tissue quickly and gently. Submerge the affected area in lukewarm water, maintained between 100°F and 108°F (38°C to 42°C), which provides rapid rewarming without the risk of thermal injury caused by hot water. Continue rewarming for 10 to 15 minutes, or until the skin’s color and sensation return. Avoid rubbing or massaging the injured tissue, as this can cause additional mechanical damage to the delicate, frozen cells.
Recognizing Severe Injury and Follow-Up Care
After initial rewarming, signs of blistering, persistent numbness, or skin that remains hard and waxy indicate a severe injury requiring immediate professional medical attention. Due to the deep freezing effect, liquid propane injuries can cause full-thickness tissue damage, similar to a third-degree thermal burn. The patient should be transported to a hospital immediately for definitive care, especially if the injury covers a large area or involves the hands, feet, or face.
Medical professionals manage the injury like a severe burn, often involving sterile dressings and pain medication. Potential complications include long-term nerve damage, infection, and tissue necrosis, which may require surgical debridement or skin grafting. Physicians also monitor for signs of vascular compromise, which can lead to compartment syndrome or the need for amputation in severe cases.