Dust Almanac

Eastern white cedar

Thuja occidentalis · Cupressaceae · softwood

Also known as: northern white cedar, white cedar, eastern arborvitae, arborvitae

Region: Eastern Canada and the northeastern and Great Lakes United States

Planed board of eastern white cedar with light tan wood, fine straight grain and a few small dark knots.

Eastern white cedar is a light, soft, aromatic, decay-resistant softwood from eastern North America. It is used for shingles, fencing, log homes, canoes, and outdoor projects.

Health hazards

  • Cancer

    Evidence: Applies to all wood dust

    IARC classifies all wood dust as carcinogenic to humans, mainly linked to cancer of the nasal cavity and sinuses after long-term heavy exposure. This applies to every species, so dust control matters whatever you cut.1

    Effects
    nasal and sinus cancer
    Exposure route
    inhalation
    From
    dust

  • Asthma / respiratory allergy

    Evidence: Confirmed in clinical testing

    Quebec shingle-mill workers developed asthma from eastern white cedar dust, confirmed by specific inhalation challenge, and plicatic acid (the red cedar asthma agent) was shown to be the cause. About 4 to 7 percent of workers at one sawmill had confirmed occupational asthma.23

    Effects
    occupational asthma
    Exposure route
    inhalation
    From
    dust

Not finding a hazard listed here does not mean this wood is safe. All wood dust is hazardous; see how to protect yourself.

Exposure limits

Workplace exposure limits (8-hour average, mg/m³)
BodyLimitNotes
ACGIH TLV1 mg/m³ (inhalable)8-hour time-weighted average, as restated by OSHA source
UK WEL (softwood)5 mg/m³Applies to all softwood dust
NIOSH REL1 mg/m³Recommended limit for all wood dust

Compare limits across agencies.

Cancer classifications

Known compounds

  • plicatic acid: causal agent of asthma; present at roughly half the level found in western red cedar source

Cross-reacts with western red cedar (Thuja plicata) through plicatic acid (Cartier-1986). People with red cedar asthma should treat this wood the same way.

Sources

  1. IARC Working Group on the Evaluation of Carcinogenic Risks to Humans. Wood Dust and Formaldehyde. IARC Monographs on the Evaluation of Carcinogenic Risks to Humans, Vol. 62. Lyon: International Agency for Research on Cancer; 1995. Link
  2. Cartier A, Chan H, Malo JL, Pineau L, Tse KS, Chan-Yeung M. Occupational asthma caused by eastern white cedar (Thuja occidentalis) with demonstration that plicatic acid is present in this wood dust and is the causal agent. J Allergy Clin Immunol. 1986;77(4):639-45. Link
  3. Malo JL, Cartier A, L'Archeveque J, Trudeau C, Courteau JP, Bherer L. Prevalence of occupational asthma among workers exposed to eastern white cedar. Am J Respir Crit Care Med. 1994;150(6 Pt 1):1697-701. Link
  4. US Occupational Safety and Health Administration. Occupational Chemical Database: Wood Dust. Last updated 06/23/2023. Link

Last reviewed .