Optical Particle Identification

Optical Particle Identification (OPID):

OPID is useful whenever large particles consisting of common indoor contaminants are present, for example, “dust bunnies” under the couch or fibrous particulate collecting on desks. The standard analytes included in the OPID are:

• Insulation: fibrous glass & mineral wool
• Cellulose: cotton fibers, plant matter, paper fiber & starches
• Synthetic fibers such as polyester from clothing and nylon from rugs
• Both human and animal hair and skin detritus
• Biologicals such as mold, pollen, diatoms & algae
• Insect fragments, moth scales, dust mites and spider silk
• Minerals are limited to asbestos, quartz (sand) and calcite

Results are expressed in particles per cubic meter for air samples and percent for dust and bulk, unless specified. We can report the results in other formats to meet your needs; just describe them on the CoC. Sampling is best achieved by grab-bag or microvacuum for dust and 0.4um PC or 0.45um MCE cassette for air. Air-O-Cell cassettes can also be used; however, differentiation of the types of insulation fibers, synthetic fibers and the types of cellulose are limited. Whenever performing air sampling it is important to collect at least one dust sample from each area. Many types of particles have a rapid settling rate and can be missed by air sampling alone.