Biodegradable lubricants rapidly decompose to water, carbon dioxide, and minerals due to the action of naturally-occurring microorganisms or enzymes present in soil or groundwater. Readily biodegradable lubricants undergo ≥60% decomposition by mass, and inherently biodegradable lubricants undergo somewhat less (between 20 and 60%), in OECD 301 testing. They are typically used in environmentally sensitive applications.

The separation of liquid from a lubricating grease, also referred to as “oil separation.”

Blending is the process of mixing components to produce a mixture with desired properties.

The surface color (usually blue or green) of a lubricating oil or grease when viewed by reflected daylight at an angle of about 45 degrees from the surface. Bloom is associated with the absorption of ultraviolet light in the oil and may not be visible if the sample is viewed using artificial light.

See Lubrication.

Visual appearance of grease when the undisturbed surface is viewed in an opaque container. See also Texture. Bulk Appearance should be described in the following terms-

• Bleeding – Free oil on the surface or in the cracks of grease.
• Cracked – Surface cracks
• Grainy – Small granules or lumps of thickener or additive particles.
• Rough – Many small irregularities.
• Smooth – Relatively free of irregularities.