Meyron

Reference summary — not medical advice or a personal risk estimate.

Formaldehyde

Group 1 — carcinogenic to humansAir & EnvironmentchemicalEvidence: sufficient_in_humans

Quick answer

Classified as Group 1 — carcinogenic to humans, based on sufficient evidence in humans. Breathed. Off-gassing from particleboard, plywood, and other pressed-wood products; embalming fluids; some hair-smoothing salon treatments; certain manufacturing.

Summary

Used in building products and preservatives. Associated with nasopharyngeal cancer and leukemia.

Detail

Formaldehyde is Group 1 with sufficient evidence for nasopharyngeal cancer and myeloid leukemia. Sources include particleboard and pressed-wood products, embalming, certain salon products and some manufacturing. Ventilation and low-emission certified products reduce home exposure.

What's not established

This classification is based on sufficient evidence in humans that this factor can cause cancer. It does not establish a safe exposure threshold, your personal risk, or how this factor's risk compares in size to other Group 1 agents — hazard classifications are not ranked by magnitude.

Regional relevance

global

global

Documented in these products

ShampooPermanent hair dyeOil-based paintTobacco smokeNail polishSemi-permanent hair dyeFace cream / moisturiserBody lotionMascaraWater-based paintAdhesive / gluePressed-wood furnitureNew carpet / rugsScented candles and incenseOld insulation (pre-1980)Hairdresser / salon workerNail technicianWildfire smokeCigarettesE-cigarettes / vapingHair conditionerBaby shampoo / washBody wash / shower gelFace wash / cleanserBaby wipesNail hardenerPlug-in air freshenerNew mattressNew synthetic clothing / textilesTextile dyeing / manufacturePhoto processing / darkroom workNail salon airHair salon airHair straightening / relaxer

Presence in a product category doesn't imply the product causes cancer. Click each to see the source and context.

Evidence sources

Every claim on this page traces back to one of these. Click through to read the primary document yourself.

Primary sources

NCI

NCI — Cancer-Causing Substances in the Environment

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IARC

IARC Monographs — Classifications by Cancer Site, Vols 1–140

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Supporting sources

ACS

ACS — Known and Probable Human Carcinogens

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Cancer Research UK

Cancer Research UK — Causes of cancer and reducing your risk

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EPA

US EPA — Integrated Risk Information System (IRIS) carcinogen assessments

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NTP

NTP — Report on Carcinogens (US National Toxicology Program)

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Last reviewed: October 2026

Official reference list

A government list some readers use alongside the primary evidence. Meyron is not affiliated with it. A chemical being listed does not by itself describe a risk from any particular product.