These petro-chemical (PC) and synthetic lubricant defoamers are available in two convenient forms: a 40% active solution in a hydrocarbon solvent (PC-1244, PC-1644, PC-1844, and PC-3144) and as a viscous liquid which is 100% active (PC-1344). All are free of unbound silicone. As received, they are stable during prolonged storage of four years or more.

PC defoamers effectively defoam both synthetic and petroleum systems due to their surface-active nature and limited compatibility. In order to effectively prevent foam formation and quickly break any foam that has formed, the defoamers exhibit a surface tension that is lower than the surrounding fluid, lubricant, or oils. The optimum particle size, to ensure efficient product performance and long-term stability in a formulated oil, is 1 to 10 microns.

Due to the differential in surface tension between the defoamer and the fluids, oils, or lubricants, the defoamer particles migrate to the surface to prevent foam formation. As materials flow from areas of low-surface tension to high-surface tension, fluid will flow away from the defoamer particle. A thinning of the bubble wall occurs until pressure differences become great enough to cause a rupture of the lamella of the air bubble.