How we research and rate the evidence

Dust Almanac exists to replace uncited wood toxicity charts with information you can check. Every hazard claim links to a source, and every hazard carries a label that says what kind of evidence stands behind it.

Evidence levels

Each hazard on a species page has one of four labels. The label depends on the type of source, not on anyone’s opinion of how dangerous a wood is. We do not use star ratings or potency scores.

Some examples:

• Western red cedar asthma is level 1: it has been confirmed by inhalation challenge in large groups of workers.¹
• Oak as a carcinogen carries level 2, because ACGIH names it specifically.²
• Every species carries a level 0 cancer entry, because IARC classifies all wood dust as carcinogenic to humans.³

A species can have several hazards at different levels. Labels are shown as text, not just color.

What the levels don’t tell you

• They are not a risk ranking. A level 3 report may describe a serious reaction; a level 1 confirmation may involve a handful of people.
• No label means “not studied”, not “safe”. Many woods have never been looked at. HSE itself notes that woods missing from its list may also cause harm.⁴ Absence of reports is not evidence of safety, and every species page says so.

Where our information comes from

We use four tiers of sources:

• Tier A: agencies and regulations. IARC monographs, OSHA, NIOSH, UK HSE, and EU law.³²⁵⁶⁷
• Tier B: peer-reviewed reviews. Used to find the original studies, such as reviews of wood dust allergy and asthma.⁸⁹¹⁰ We cite the original study wherever we can.
• Tier C: primary studies. Case reports, clinical studies and workplace surveys. These are the main sources on species pages.
• Tier D: technical references. Botanical name databases and timber references, used for names and wood facts, not health claims.

For each source we record the DOI, PubMed ID or official URL, when we accessed it, and whether we checked it ourselves. If we couldn’t verify something, we say so in our review notes rather than filling the gap from memory.

Sources we don’t cite

Popular wood toxicity charts, compiled databases and forum posts are useful for spotting woods we haven’t covered yet. We never cite them as evidence or copy them. We go back to the original studies instead.

Botanical names

Trade names are confusing: one name can cover several trees, and one tree can have several names. We check every botanical name against Plants of the World Online or World Flora Online, and note old names as synonyms. Where a source names only a trade name, we say so.

Data and copyright policy

• Facts, in our own words. Facts such as “this wood has caused asthma” are not copyrighted, but other people’s wording, charts and rating systems are. We write every summary ourselves and never paste abstracts or chart entries.
• Built species by species. We build each entry from primary sources, not by reworking someone else’s chart.
• Images are our own or carry a clear open license, with credit recorded.
• Exposure limits come from the official current documents. Where a document has been withdrawn or replaced, we use the current one.

This is not legal or medical advice. It is a reference that points you to the original sources.

Reviews and dates

Each page and species card shows a “last reviewed” date. Sources and limits change; if you spot something out of date, please tell us.

How to contribute

Corrections and additions are welcome, and no account is needed. Use the Report a correction link on any species page, or Suggest a species.

What we need

• For a new hazard or correction: the species, what should change, and a source with a DOI, PubMed ID or official agency URL.
• For a better source: the claim it supports and the full citation.
• Write in your own words. Please don’t paste abstracts or charts.

What happens next

Every submission is manually reviewed. Accepted changes go through the same review and validation as the rest of the data. After you submit, you get a private status link to follow its progress.

Reporting a reaction

You can tell us you reacted to a wood. These reports help us decide what to research, but they are never published and are not a medical service. If you have symptoms, see a doctor (Symptoms).

Thanks

Dust Almanac was inspired by The Wood Database, Eric Meier’s long-running reference on wood species, which has helped countless woodworkers identify woods and learn about their hazards. We built our own entries from primary sources so every claim can be traced, but the idea of a friendly, species-by-species guide is theirs. If you want to know how a wood looks, works and finishes, start there.

Last reviewed 2026-11-07.