Why should oxygen cylinder regulators be strictly avoided from contact with grease during use?

Oxygen is relatively stable at room temperature, but it will show strong oxidizing properties under high pressure, high temperature or high-speed airflow. Organic substances such as grease and lubricants are very susceptible to oxidation reactions under these conditions, especially in an environment containing concentrated oxygen. The chemical bonds of these substances will quickly break under the action of oxygen, releasing a large amount of heat energy, which will cause combustion or even explosion.
There is usually a high-pressure oxygen environment in the oxygen cylinder regulator, especially at the connection with the oxygen cylinder, where the pressure may be as high as 150-200 bar (about 2200-3000 psi). Under this high pressure, the oxidizing ability of oxygen is enhanced. If combustibles such as grease are present, oxygen will react with it quickly to produce local high temperature. This reaction process can spontaneously ignite without an open flame, which is called "compression combustion" or "spontaneous combustion", which is also the root cause of the danger when grease comes into contact with oxygen.
Grease contacting oxygen cylinder regulators may cause the following safety hazards:
Fire risk: Once grease and oxygen undergo a violent oxidation reaction, the high temperature generated can ignite other combustible materials in the regulator, causing fire inside or near the equipment, which may cause serious personal injury.
Explosion risk: Under high pressure conditions, the spontaneous combustion of grease can not only cause fires, but also explosions, especially in closed or confined oxygen systems. Once an explosion occurs, the regulator, oxygen cylinder, and even the entire oxygen supply system may be destroyed in an instant.
Damage to equipment: Even if there is no fire or explosion, the presence of grease will generate heat when oxygen flows, causing the local temperature of the equipment to be too high, causing damage or failure of the regulator components. In addition, grease will block the valves or channels inside the regulator, affecting the normal circulation of oxygen, and thus affecting the oxygen supply function of the regulator.