Pellet Mills. Throughout North America, pellet mills receive, sort, grind, dry, compress and bag wood and other biomass waste products into a conveniently handled pelletized fuel. Today, over 80 pellet mills across North America produce in excess of 1.1 Million tons of fuel per year.

Pellet Appliances. There are more than 23 fireplace manufacturers that produce pellet stoves and fireplace inserts. Due to the attractiveness of pellet heat to the consumer market, pellet appliance manufacturers are committed to supporting the category and investing in research to further the sophistication of the appliances.

Industry Standards. The pellet fuel industry has developed fuel standards that must be met by all pellet mills. These industry standards assure as much uniformity in the final product as is possible for naturally grown materials that become processed, but not refined, fuel. The pellet fuel industry, through the PFI, has determined that pellet mills have the responsibility to test and certify their product. The Institute recommends that manufacturers conduct both in-plant and independent laboratory tests of their product on a regular basis.

PFI-graded fuel must meet tests for:

• Density: consistent hardness and energy content (minimum 40 pounds/cubic foot)
• Dimensions: length (1 ½” maximum) and diameter (1/4” x 5/16”) to assure predictable fuel amounts and to prevent jamming
• Fines: limited amount of sawdust from pellet breakdown to avoid dust while loading and problems with pellet flow during operation (amount of fines passing through 1/8” screen no more than .5 percent by weight)
• Chlorides: limited salt content (no more than 300 parts per million) to avoid stove and vent rusting
• Ash content: important factor in maintenance frequency

Grades of Pellets
Pellet mills produce two grades of fuel – Premium and Standard. The only difference between the two is ash content. Standard grade fuel is usually up to 3% ash content, while premium grade is less than 1 percent. This difference is a result of the pellet contents. Standard pellets are derived from materials that produce more residual ash, such as tree bark or agricultural residues. Premium pellets are usually produced from hardwood or softwood sawdust containing no tree bark. Premium pellets make up 95 percent of current pellet production and can be burned in all appliances. Standard pellets should only be burned in appliances designed to burn the higher ash content pellets.

TESTING LABS
American Interplex Corp. Laboratories 8600 Kanis Road Little Rock, AR 72204 Ph: 501/224-5060 Fax: 501/224-5072	Envirocompliance Laboratories, Inc. 10357 Old Keeton Road Glen Allen, VA 23059 Ph: 804/550-3971 Fax: 804/550-3826
Interpoll Laboratories 4500 Ball Road, NE Circle Pines, MN 55014-1819 Ph: 612/786-6020 Fax: 612/786-7854	MVTL Laboratories PO Box 1873 Bismarck, ND 58502 Ph: 701/258-9720 Fax: 701/258-9724
OMNI-Test Laboratories/OMNI Environmental Services 5465 SW Western Ave., Suite G Beaverton, OR 97005 Phone:  503/643-3788 Fax:  503/643-3799	PSI (formally Braun Intertech Northwest, Inc.) PO Box 17126 Portland, OR 97217 Ph: 503/289-1778 Fax: 503/289-1918
RADCO 3220 East 596 Street Long Beach, CA 90805 Ph: 562/272-7231 Fax: 562/529-7513	Timber Products Inspection 1641 Sigman Road Conyers, GA 30012 Phone:  770-922-8000 ext. 302 Fax:  770-785-6192
Twin Ports Testing 1301 North 3 Street Superior, WI 54880 Ph: 715/392-7114 Fax: 715/392-7163	Wood Science & Technology Centre University of New Brunswick 1350 Regent Street Fredericton, N-B E3C 2G6 CANADA Ph: 506/453-4507 Fax: 506/453-3574