At a glance
| Chemical family | Engineered nanoparticulate — amorphous carbon produced by hydrocarbon combustion (not the same as soot) |
| CAS number | 1333-86-4 |
| Classification | IARC Group 2B (possibly carcinogenic to humans, Monographs Vol. 93, 2010). Lung inflammation and tumour development in rats at high doses. The key distinction from soot: carbon black is manufactured with controlled properties |
| Where you encounter it | Tires and rubber products (major use); printing inks and toners; plastics and coatings; carbon paper; house dust (from printers, tire wear, and rubber products) |
| Sleep micro-environment relevance | Present in bedroom air and dust from laser printer/copier toner emissions and from outdoor tire wear dust infiltration. Some black-pigmented rubber mattress components contain carbon black |
Regulatory & certification status
| European Union | REACH registered. Not on the SVHC candidate list. CLP does not classify carbon black as a carcinogen (the EU classification committee considered the rat lung overload mechanism not relevant to humans at occupational exposures). No consumer product restriction. Regulatory |
| United States | OSHA PEL: 3.5 mg/m3 (TWA). NIOSH REL: 3.5 mg/m3 (TWA), 0.1 mg/m3 for ultrafine carbon black. California Proposition 65 listed (cancer, based on IARC 2B). Regulatory |
| Canada | OEL: 3.5 mg/m3 (TWA). No consumer product restriction. Regulatory |
| International | IARC Group 2B (possibly carcinogenic, Monographs Vol. 93, 2010). Not classified as a carcinogen by the EU CLP committee. ACGIH TLV: 3 mg/m3 (inhalable fraction). Regulatory |
What it is
Carbon black is an industrially manufactured form of elemental carbon produced by the controlled incomplete combustion or thermal decomposition of hydrocarbons (natural gas or petroleum). It consists of near-spherical primary particles (10-500 nm) that aggregate into larger structures. Carbon black is not the same as soot — it is manufactured with controlled particle size, surface area, and structure, while soot is an uncontrolled byproduct of combustion. IARC evaluated carbon black in 2010 and classified it as Group 2B based on sufficient evidence of carcinogenicity in rats (lung tumour development after chronic inhalation of high concentrations) and inadequate evidence in humans. The mechanism in rats — particle overload, persistent inflammation, and secondary genotoxicity — may be a rat-specific high-dose phenomenon rather than predictive of human cancer risk at lower exposures.
Where it shows up in bedding
Carbon black is not a standard bedding ingredient, though some black-pigmented rubber components (mattress feet, elastic bands, rubber grips) may contain it. The more relevant bedroom exposure pathways are: (1) toner particle emissions from laser printers or photocopiers placed in or near the bedroom — these emit ultrafine particles that include carbon black and other toner components; and (2) outdoor tire wear dust that infiltrates indoors through windows, doors, and ventilation. Tire wear particles (TWP) are composed primarily of tire rubber (which is approximately 30% carbon black by weight) and road surface material. In urban bedrooms near busy roads, tire wear-derived carbon black can be a significant component of indoor particulate matter.
Citations
- IARC (2010). Carbon Black. IARC Monographs Vol. 93. Source Peer-reviewed
- Baan, R.A. (2007). Carcinogenic hazards from inhaled carbon black, titanium dioxide, and talc not containing asbestos or asbestiform fibers. The Lancet Oncology, 8(9): 763-764. Source Peer-reviewed
- ECHA. Carbon Black — Substance Information. Source Regulatory
Frequently asked questions
Should I move my printer out of the bedroom?
Yes, if practical. Laser printers and photocopiers emit ultrafine particles during printing — these particles include toner components that contain carbon black. Placing the printer in a separate, ventilated room reduces overnight particle exposure. Inkjet printers produce fewer particle emissions than laser printers.
Is carbon black the same as soot?
No. Carbon black is a manufactured material with controlled particle size, surface area, and purity. Soot is an uncontrolled byproduct of incomplete combustion that contains PAHs, metals, and other contaminants in addition to elemental carbon. The distinction is important because soot's carcinogenicity (IARC Group 1 for some occupational exposures) is partly driven by its PAH content, while carbon black's Group 2B classification is based on a particle-overload mechanism in rat lungs.
Related compounds
Embr is a sleep environment company researching and addressing the chemistry of the bedroom. Research and product development in progress.
Last reviewed 2026-07-08. If you find a factual error, contact us.