With some common-sense precautions, it is safe to handle and dispose of fire-retardant-treated wood products.
As with other wood products, wear long-sleeved shirts and long pants and use gloves when handling fire retardant lumber.
Follow good personal hygiene after handling fire retardant wood. Wash hands and any exposed areas thoroughly after handling, especially before eating, drinking or using tobacco products.
Avoid inhalation of sawdust from fire retardant wood products. When sawing the wood, wear a dust mask. When power-sawing, wear goggles to protect eyes from flying particles.
Sawdust or chips from fire retardant wood should not be used as mulch or for landscaping. If sawdust from fire retardant wood accumulates on clothes, launder before reuse. Launder work clothes separately from other household clothing.
At the end of the service life of fire retardant wood, either because it has become obsolete with new development or because it has fulfilled its life expectancy, it should be disposed properly.
Wood preservatives used in pressure treating are covered under the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA). This does not apply to fire retardants because they are not considered pesticides intended to keep biological agents from deteriorating the wood.
As such, disposal of fire retardant wood can be treated nearly the same as untreated wood. It can be disposed of normally into a landfill, provided you check local or state regulations.
Of course, burning fire retardant wood is not advised, since even at the end of its service life, it still retain is protective qualities against fire. However, it can be burned in commercial or industrial incinerators or boilers in accordance with federal, state and local regulations.