Standards, Certifications, and Codes

The American National Standard for Particleboard, ANSI A208.1 (see table 3 online), classifies particleboard by density and class and is the voluntary particleboard standard for the North American industry. The standard, which covers physical and mechanical properties and dimensional tolerances as well as formaldehyde emission limits, was developed through the efforts of the Composite Panel Association (CPA, see sidebar), producers, users, and general interest groups.

The ANSI standard for Medium Density Fiberboard, ANSI A208.2 (see Table 4 online), is the North American industry voluntary standard for MDF and classifies MDF by physical and mechanical properties and identifies product grades. Specifications identified in the standard include physical and mechanical properties, dimensional tolerances, and formaldehyde emission limits.

A summary of the ANSI Property Requirements are included in CPA's Buyer's and Specifiers Guide to North American Particleboard, Medium Density Fiberboard, and Hardboard Products and Manufacturers, 2005, which is available online (www.pbmdf.com). Copies of the complete ANSI Standards for Particleboard and MDF are also available from CPA.

Third-party certification to ANSI Standards is required for many applications of composite panels. For example, the U.S. Department of Housing and Urban Development (HUD) requires the physical and mechanical properties of manufactured home decking to be third-party certified. Many building code jurisdictions require the physical and mechanical properties of particleboard underlayment and stair tread to be third-party certified. HUD requires third-party certification of formaldehyde emissions for particleboard used in mobile homes. The state of Minnesota requires MDF used as a "building material" to comply with HUD formaldehyde emissions for particleboard.

Formaldehyde in Particleboard and MDF

Approximately 80-85 percent of the typical composite panel is wood. The rest consists of resin binders, additives, and water. The adhesive (resin) most often used by the North American composite panel industry is UF. This resin is strong, colorless, economical, and provides performance criteria specified for most interior uses. The "formaldehyde" used in UF resins is a colorless chemical that is part of a large family of "volatile organic compounds" (VOCs)-those that become a gas at normal room temperature.

Over the past 15 years, technology has significantly reduced the free formaldehyde, which contributed to emissions. Panels produced today, on average, emit only about one-sixth as much formaldehyde as those produced in the early 1980s.

ANSI A208.1-1999 established voluntary formaldehyde emission limits for particleboard. These include emission limits of 0.30 parts per million (ppm) for standard industrial grades and 0.20 ppm for flooring grades. Emission limits are based on values determined under specified conditions in a standard large chamber with product loading ratios of 0.425 square meter/cubic meter (0.13 square feet/cubic feet). ANSI A208.2-2002 sets the voluntary formaldehyde emission limit for MDF at 0.30 ppm at a loading ratio of 0.26m 2/m3 (0.08 ft2/ft3).