A pressure washer uses a high-velocity stream of water compressed through a narrow nozzle to clean various surfaces. The force generated by this equipment is substantial, reaching pressures high enough to cut through wood or concrete. Improper use can result in fatal accidents due to the extreme physical and electrical forces involved, which can cause severe trauma to the human body.
The Danger of High-Pressure Injection
The most unique hazard associated with pressure washing is the high-pressure injection injury. These machines can generate pressures over 2,500 pounds per square inch (PSI), but pressure as low as 100 PSI is sufficient to penetrate human skin. This force turns the water stream into a hypodermic needle, piercing the skin and injecting water, cleaning chemicals, or bacteria deep into the underlying tissues.
The initial wound may look deceptively minor, often just a small puncture mark, causing the injured person to delay seeking treatment. However, the injected material causes rapid internal damage, leading to severe swelling and increased pressure within the body’s compartments. This condition, known as compartment syndrome, can quickly restrict blood flow and cause tissue necrosis. Furthermore, foreign substances or bacteria introduced beneath the skin can lead to life-threatening infections like sepsis, or the formation of embolisms if forced into the bloodstream. Immediate surgical intervention is often necessary to decompress the tissue and prevent permanent disability or death.
Fatal Electrical Hazards
The combination of high-pressure water and electricity creates a significant risk of electrocution. Electric pressure washer models carry this risk directly through their power cords and motors. Using a unit with a damaged cord, operating the equipment in standing water, or having wet hands on the electrical components can complete a deadly circuit.
Gas-powered washers do not eliminate the electrical hazard entirely, as many accessories and components may still involve electrical connections. To mitigate the risk of severe electric shock, electric pressure washers should be plugged into a Ground Fault Circuit Interrupter (GFCI). A GFCI constantly monitors the flow of electricity and rapidly cuts power to the unit if it detects an irregularity. This device acts as a safeguard, tripping the circuit faster than a typical circuit breaker, which can prevent a fatal shock.
Serious Projectile and Fall Risks
Beyond the direct hazards of injection and electrocution, pressure washers present indirect dangers that can cause severe trauma. The sheer force of the water stream can transform loose debris on a surface into high-velocity projectiles. Gravel, paint chips, wood splinters, and other materials can be launched at speeds sufficient to cause severe eye, head, and facial trauma.
The recoil, or kickback, generated by the powerful spray wand can lead to dangerous instability for the operator. If the user is on an elevated platform, such as a ladder or scaffolding, the sudden force can cause a loss of balance and a serious fall. Additionally, pressure washing creates extremely slippery conditions from the combination of water, soap, and loosened grime. A simple slip on this wet surface can result in severe injuries like concussions or broken bones, especially if the operator falls onto the running equipment.
Safe Operation Practices
Preventing severe outcomes begins with wearing appropriate protective equipment. This includes safety goggles or face shields to guard against flying debris, closed-toe shoes with non-slip soles, and gloves to protect hands from the stream and electrical components. Before starting the machine, inspect all hoses, connections, and electrical cords for signs of wear or leaks.
The nozzle should never be pointed at people, pets, or any part of the body. If using a gas-powered model, operate it exclusively in open, outdoor areas with ample ventilation. Gas engines emit high concentrations of carbon monoxide, which can rapidly cause poisoning, unconsciousness, and death if used in an enclosed space. Always ensure the unit is plugged into a functional GFCI outlet to protect against electrical faults and never bypass any safety features.