Dust Almanac

Redwood

Sequoia sempervirens · Cupressaceae · softwood

Also known as: California redwood, coast redwood, sequoia

Region: Coastal northern California and southern Oregon, USA

Planed board of coast redwood with reddish-brown heartwood, straight banded growth rings and a pale sapwood edge.

Coast redwood is a light, reddish, decay-resistant softwood from coastal California and Oregon. It is used for decking, siding, outdoor furniture, planters, and burl veneer and turning stock.

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

    Three workers have been reported with asthma from redwood sawdust, each confirmed by an exposure or inhalation challenge test. The cause is thought to be small chemical compounds in the wood.23

    Effects
    occupational asthma
    Exposure route
    inhalation
    From
    dust

  • Hypersensitivity pneumonitis

    Evidence: Reported

    'Sequoiosis' is a lung inflammation described in 1967 in people who breathed redwood sawdust. It is often attributed to molds growing on moldy redwood dust rather than the wood itself, but we could not confirm that from the original abstract.4

    Effects
    sequoiosis, granulomatous pneumonitis
    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

Giant sequoia (Sequoiadendron giganteum) and dawn redwood (Metasequoia) are different trees. In European timber trade 'redwood' often means Scots pine (see the pine page).

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. Chan-Yeung M, Abboud R. Occupational asthma due to California red wood (Sequoia sempervirens) dusts. Am Rev Respir Dis. 1976;114(5):1027-31. Link
  3. doPico GA. Asthma due to dust from redwood (Sequoia sempervirens). Chest. 1978;73(3):424-5. Link
  4. Cohen HI, Merigan TC, Kosek JC, Eldridge F. Sequoiosis. A granulomatous pneumonitis associated with redwood sawdust inhalation. Am J Med. 1967;43(5):785-94. Link
  5. US Occupational Safety and Health Administration. Occupational Chemical Database: Wood Dust. Last updated 06/23/2023. Link

Last reviewed .