At a glance
| Chemical family | Chlorinated persistent organic pollutants; a class of 209 possible congeners rather than a single substance. Filed under building & environmental sources, because PCBs reach a bedroom as legacy residue and not as a product ingredient |
| CAS number | 1336-36-3. Read this identifier carefully: it names the whole class, not one molecule. PubChem returns no compound record for it, and the NTP profile defines the entry as polychlorinated biphenyls carrying one to ten chlorine atoms |
| Classification | IARC Group 1, carcinogenic to humans (Monograph Volume 107). The US National Toxicology Program reaches the weaker call of "reasonably anticipated to be human carcinogens", first listed in 1981. EU harmonised classification: STOT RE 2 (H373), Aquatic Acute 1 (H400), Aquatic Chronic 1 (H410) |
| Where you encounter it | House dust, chiefly in older buildings: PCB-containing caulk and elastic sealants, heat insulation, and the capacitors in pre-1979 fluorescent light ballasts. A smaller current source is inadvertent formation during pigment manufacture |
| Sleep micro-environment relevance | Settled dust and indoor air, not emissions from bedding. The routes worth naming are inhalation of indoor air and incidental dust ingestion, which matters most for crawling toddlers |
| Activated carbon capture | Not the control that matters here. PCBs are semivolatile and partition into dust and onto surfaces, so filtration may capture particle-bound material while leaving the source untouched; no study in this evidence base measured a bedroom-level reduction from any device Inferred — from the compound's semivolatile, dust-partitioning behaviour |
Regulatory & certification status
PCBs are one of the few compounds in this Atlas where the word "banned" is literally accurate rather than loose. Each row states the governing instrument for that jurisdiction. Where a status could not be confirmed against a primary source, it is left unasserted rather than filled in.
| European Union | Prohibited. PCBs are listed in Annex I Part A of the POPs Regulation (EU) 2019/1021 under CAS 1336-36-3 / EC 215-648-1, which bans manufacture, placing on the market and use. That is a genuine prohibition, unlike a REACH Candidate List identification or a CLP hazard classification. One exemption is recorded: "Without prejudice to Directive 96/59/EC, articles already in use at the time of entry into force of this Regulation are allowed to be used." Regulatory — EUR-Lex |
| EU harmonised classification | Present, but narrow. CLP Annex VI Table 3 carries "polychlorobiphenyls; PCB" at Index No. 602-039-00-4 with STOT RE 2 (H373), Aquatic Acute 1 (H400) and Aquatic Chronic 1 (H410), signal word Warning, and a specific concentration limit of C ≥ 0.005% for H373. Note what is absent: no carcinogenicity classification appears in the harmonised entry, even though IARC places PCBs in Group 1. Annex VI covers only the harmonised subset agreed by Member States, and it has not been revisited for PCBs since the original CLP entry became applicable on 1 December 2010. Absence from Annex VI is not absence of hazard. Regulatory — ECHA, CLP Annex VI Table 3, Index No. 602-039-00-4 |
| United States | Prohibited by statute. TSCA section 6(e) bans manufacture, processing and distribution in commerce, with implementing rules at 40 CFR Part 761; US manufacture stopped in August 1977. EPA IRIS carries PCBs as CASRN 1336-36-3. The National Toxicology Program lists them in the Report on Carcinogens as "reasonably anticipated to be human carcinogens", a weaker conclusion than IARC's, held since 1981. California Proposition 65 lists polychlorinated biphenyls for cancer (1 October 1989, No Significant Risk Level 0.09 µg/day) and for developmental toxicity (1 January 1991); a separate entry covering PCBs of 60% or more chlorine by molecular weight was listed for cancer on 1 January 1988. Regulatory — OEHHA · NTP |
| Canada | Prohibited, but not by the instrument several neighbouring pages in this Atlas cite. PCBs are not covered by the Prohibition of Certain Toxic Substances Regulations, 2025 (SOR/2025-270), which addresses polybrominated biphenyls and polychlorinated terphenyls and mentions chlorobiphenyls only in an exemption clause. They are controlled instead by the dedicated PCB Regulations (SOR/2008-273) under the Canadian Environmental Protection Act, 1999, whose section 6 provides that "Except as provided in these Regulations, no person shall (a) manufacture, export or import PCBs or a product containing PCBs in a concentration of 2 mg/kg or more", with release limits of 2 mg/kg for liquids and 50 mg/kg for solids. Regulatory — PCB Regulations (SOR/2008-273) under CEPA 1999 |
| United Kingdom | Prohibited. The assimilated Regulation (EU) 2019/1021, as amended, continues to apply in Great Britain, and PCBs remain in its Annex I, so Article 3(1) prohibits manufacture, placing on the market and use subject to Article 4. Equipment and disposal duties run through the Environmental Protection (Disposal of Polychlorinated Biphenyls and other Dangerous Substances) (England and Wales) Regulations 2000 as amended by SI 2020/489, which required equipment containing more than 0.005% PCBs in volumes above 0.05 dm³ to be taken out of use no later than 31 December 2025. The UK is a Party to the Stockholm Convention in its own right. Regulatory — assimilated POPs Regulation (EU) 2019/1021; the 2000 Disposal Regulations as amended by SI 2020/489 |
| Australia | Australia ratified the Stockholm Convention on 20 May 2004, in force for Australia on 18 August 2004, and is reported to have prohibited import and manufacture of PCBs in the 1970s. Secondary reporting also describes a later Schedule 7 designation on the IChEMS Register, but the primary instrument could not be opened for this page, so neither that designation nor its effective date is asserted here. Regulatory — Stockholm Convention ratification record for the 2004 dates; the 1970s prohibition and the IChEMS designation rest on secondary reporting, not a primary instrument read for this page |
| International | Listed under the Stockholm Convention in Annex A (elimination, with specific exemptions) and Annex C (unintentional production). PCBs are one of the original twelve POPs named when the Convention text was adopted in 2001, in force 2004. Two operational deadlines follow: identify, label and remove PCB-containing equipment from use by 2025, and achieve environmentally sound waste management of PCB liquids and contaminated equipment no later than 2028. IARC classifies polychlorinated biphenyls as Group 1, and separately places the dioxin-like PCBs carrying a WHO Toxicity Equivalency Factor (PCBs 77, 81, 105, 114, 118, 123, 126, 156, 157, 167, 169, 189) in Group 1, both in Volume 107. Regulatory — IARC |
| Certifications | No credible certification scheme tests bedding for PCBs, and none needs to: the substance is prohibited across the major markets and is not in the textile or foam supply chain. A product advertised as "PCB-free" is making a marketing statement, not reporting a measurement. Inferred — from the prohibition status and the absence of any bedding-relevant use |
| The 72-hour test window | Missed entirely, and beside the point here. A short chamber emissions test is built to catch volatile organics coming off a new product. PCBs are semivolatile, they partition into dust and onto surfaces, and there is no bedding source for a chamber to detect in the first place. Inferred — from the compound's volatility profile versus the VOC focus of short chamber tests |
What it is
PCBs are a family of chlorinated aromatic compounds built on a biphenyl backbone, carrying anywhere from one to ten chlorine atoms. That gives 209 theoretically possible congeners, which is why the CAS number on this page behaves differently from most in the Atlas: 1336-36-3 identifies the class, and PubChem returns no single compound record for it. Commercial mixtures were sold under trade names such as Aroclor.
Industry valued them for being chemically stable, heat-resistant and electrically insulating. Those properties made excellent dielectric fluids for transformers and capacitors, and useful plasticisers in sealants and paints. Every trait that made them good at those jobs also made them almost impossible to get rid of. They resist breakdown, they accumulate in fat, and they stay in buildings long after the products containing them are gone.
The carcinogenicity assessments have not converged. IARC's classification list records "001336-36-3 Polychlorinated biphenyls 1 18, Sup 7, 107 2016", placing the class in Group 1, carcinogenic to humans. Regulatory — IARC classification list The US National Toxicology Program says instead that PCBs "are reasonably anticipated to be human carcinogens based on sufficient evidence of carcinogenicity from studies in experimental animals", a position it has held since 1981. Regulatory — NTP Report on Carcinogens Both calls are current, from bodies reading the same literature. Showing the gap is more useful than quietly picking the scarier one.
Where it shows up in the bedroom
Not in the bed. ATSDR's toxicological profile states that "No known consumer product currently manufactured in the United States contains PCBs, but PCBs are still released during some industrial processes." Regulatory — ATSDR Toxicological Profile PCBs were dielectric fluids and plasticisers, never sold as a mattress flame retardant, and nothing in a mattress, a pillow, a duvet or a set of sheets made today contains them. There is no bedding source to remove.
They are still in the room, though, and the measurements are unambiguous. Harrad and colleagues sampled domestic dust in four countries and reported median total PCB concentrations of 200 ng per gram in Texas homes, 260 ng/g in Toronto, 48 ng/g in Birmingham and 46 ng/g in Wellington. Peer-reviewed — Harrad et al. 2009 Those were ordinary homes, sampled decades after the ban.
Persistence indoors is a matter of slow removal rather than fresh supply. Whitehead and colleagues, working from California residential dust, concluded that "Estimated half-lives ranged from 5-18 years, indicating that PCBs are removed very slowly from the indoor environment", and found that home age explained differences between houses, with older homes carrying more. Peer-reviewed — Whitehead et al. 2014 Construction from before 1979 is where the classic indoor sources sit: PCB-containing caulk and elastic sealants, heat insulation, and the capacitors inside fluorescent light ballasts, which ATSDR notes can warm during operation and raise indoor air levels.
One finding reframes where to look. DellaValle and colleagues examined carpet dust from 1,187 US homes and reported that "Our findings suggest that outdoor sources of PCBs may be significant determinants of indoor concentrations", with developed land and population density tracking indoor levels. Peer-reviewed — DellaValle et al. 2013 A bedroom is largely receiving PCBs, from outdoors and from its own building fabric, rather than generating them.
A single qualification keeps this from being purely historical. Hu and Hornbuckle tested 33 commercial paint pigments bought from three local paint stores and detected more than 50 PCB congeners, several of them dioxin-like, formed inadvertently during pigment manufacture. Peer-reviewed — Hu & Hornbuckle 2010 PCB-11 is one of the congeners formed on that pathway. A freshly painted bedroom wall is therefore a small, current and entirely legal source in a way that no mattress is.
What the research says
- Measurable in ordinary house dust across four countries. Median total PCBs of 46 to 260 ng/g in homes sampled in the US, UK, Canada and New Zealand. Peer-reviewed — Harrad et al. 2009
- Estimated indoor half-life of 5 to 18 years. Removal from the indoor environment is very slow, and home age explains differences between houses, with older homes carrying more. Peer-reviewed — Whitehead et al. 2014
- Outdoor determinants matter. Across carpet dust from 1,187 US homes, indoor levels tracked developed land and population density. Peer-reviewed — DellaValle et al. 2013
- A small current source still exists. More than 50 congeners, including dioxin-like ones, were detected in 33 retail paint pigments as inadvertent by-products of manufacture. Peer-reviewed — Hu & Hornbuckle 2010
- No consumer product source. US manufacture ended in August 1977, and no consumer product currently made in the country contains PCBs. Regulatory — ATSDR Toxicological Profile
- The two cancer calls differ. IARC says Group 1, carcinogenic to humans; NTP says reasonably anticipated to be a human carcinogen. Regulatory — IARC classification list · NTP Report on Carcinogens
What helps reduce it
Wet-cleaning and HEPA vacuuming. The pathway is settled dust rather than a continuous emission, so removing dust acts on the actual route. Whitehead's within-home trends showed indoor levels do decline, just slowly. Peer-reviewed — Whitehead et al. 2014
Know the age of the building. Home age explained differences between homes, and pre-1979 construction is where PCB-containing caulk, sealants and fluorescent-ballast capacitors are concentrated. Peer-reviewed — Whitehead et al. 2014
Retire pre-1979 fluorescent light fittings. ATSDR identifies these ballasts as a source that can warm during operation and raise indoor air PCB levels. A light fitting is a discrete removable object rather than a diffuse condition, which makes this one of the few clean wins available. Regulatory — ATSDR Toxicological Profile
Get a professional assessment before renovating an older building. Disturbing PCB-containing caulk or sealant is what converts a static source into an airborne one. Inferred — from the documented building-material sources and the dust pathway
Hand-washing before meals for young children. Incidental dust ingestion is the route where toddlers diverge from adults, which makes hand hygiene a bigger lever for them than for anyone else in the house. Inferred — from the dust-ingestion exposure route
What does NOT help
- Replacing the mattress. No PCB source exists in modern bedding, so a new bed changes nothing about PCB exposure. On a site about mattress chemistry, that is the single most important sentence on this page. Regulatory — ATSDR Toxicological Profile
- Hunting for a "PCB-free" certification on a sleep product. No credible scheme tests bedding for PCBs, because the substance is prohibited and is not used in the supply chain. Inferred — from the prohibition status and the absence of any bedding use
- Airing the room out the way you would for foam VOCs. PCBs are semivolatile and partition into dust and onto surfaces. An estimated 5-to-18-year indoor half-life is not something a weekend of open windows resolves. Peer-reviewed — Whitehead et al. 2014
- Assuming an old-house dust problem is an indoor-materials problem. Outdoor sources may be significant determinants of indoor levels, so source-hunting confined to the bedroom can miss the real driver. Peer-reviewed — DellaValle et al. 2013
- Buying an air purifier as the primary control. Filtration may capture particle-bound PCBs, but it does nothing about the source, and no study in this evidence base measured a bedroom-level reduction from one. Inferred — no intervention study in the sources reviewed measured a bedroom-level reduction
Open research questions
- Whether the inadvertent-formation pathway that puts PCB-11 into paint pigments also puts it into dyed textiles. That would be a genuine bedding-level source rather than a room-level one, and no source reviewed here establishes it. Speculation
- No measured PCB concentration exists for a sleeping-environment microenvironment specifically: the bed, the bedding, or the breathing zone during sleep. This matches what the Atlas keeps finding across compounds. Presence is documented; sleeping-zone dose is not. Inferred — no such measurement appears in any source reviewed for this page
- Australia's reported IChEMS Schedule 7 designation for PCBs rests on secondary reporting only. The primary instrument needs to be read before this page asserts it. Inferred — secondary sources only; primary instrument not opened
- IARC's classification list dates Monograph Volume 107 to 2016 while the IARC publications catalogue gives 2015; the Working Group met in 2013. This page uses 2016, the date printed in the classification list itself. Regulatory — IARC classification list
The exposure ledger for Polychlorinated biphenyls (PCBs)
One chemical, several public questions, answered from independent datasets and joined here — the environment it shows up in, the body burden it carries, how it is regulated, and what actually reduces it.
Detection and body-burden figures are occurrence data, not a personal measurement or a health diagnosis. Part of the Embr Exposure Ledger — an open, cross-dataset chemical join (download the data), reusable with attribution.
Where you meet Pcbs across your home
The same compound turns up in more than one place you live. Here's where it shows up in Embr — each links to the full breakdown for that part of your home.
Citations
- Harrad S, Ibarra C, Robson M, Melymuk L, Zhang X, Diamond M, Douwes J (2009). Polychlorinated biphenyls in domestic dust from Canada, New Zealand, United Kingdom and United States: Implications for human exposure. Chemosphere. Median total PCB dust concentrations of 200 ng/g (Texas), 48 ng/g (Birmingham), 260 ng/g (Toronto) and 46 ng/g (Wellington). DOI 10.1016/j.chemosphere.2009.03.020 Peer-reviewed
- Whitehead TP, Brown FR, Metayer C, Park JS, Does M, Dhaliwal J, Petreas MX, Buffler PA, Rappaport SM (2014). Polychlorinated Biphenyls in Residential Dust: Sources of Variability. Environmental Science & Technology. Estimated indoor half-lives ranged from 5 to 18 years, indicating PCBs are removed very slowly from the indoor environment. DOI 10.1021/es403863m Peer-reviewed
- DellaValle CT, Wheeler DC, Deziel NC, De Roos AJ, Cerhan JR, Cozen W, Severson RK, Flory AR, Locke SJ, Colt JS, Hartge P, Ward MH (2013). Environmental Determinants of Polychlorinated Biphenyl Concentrations in Residential Carpet Dust. Environmental Science & Technology. Carpet dust from 1,187 US homes; outdoor sources may be significant determinants of indoor concentrations. DOI 10.1021/es401447w Peer-reviewed
- Hu D, Hornbuckle KC (2010). Inadvertent Polychlorinated Biphenyls in Commercial Paint Pigments. Environmental Science & Technology. 33 pigments from three retail paint stores; more than 50 congeners detected, including several dioxin-like PCBs. DOI 10.1021/es902413k Peer-reviewed
- Agency for Toxic Substances and Disease Registry (2000). Toxicological Profile for Polychlorinated Biphenyls (PCBs). U.S. Department of Health and Human Services. "No known consumer product currently manufactured in the United States contains PCBs, but PCBs are still released during some industrial processes." ATSDR Regulatory
- National Toxicology Program (2021). Report on Carcinogens, Fifteenth Edition — substance profile: Polychlorinated Biphenyls. U.S. Department of Health and Human Services. CAS No. 1336-36-3; reasonably anticipated to be human carcinogens; first listed in the Second Annual Report on Carcinogens (1981). NTP Regulatory
- International Agency for Research on Cancer (2016). Agents Classified by the IARC Monographs, Volumes 1–123. World Health Organization. Polychlorinated biphenyls, Group 1, Volumes 18, Sup 7 and 107; dioxin-like PCBs with a WHO Toxicity Equivalency Factor separately in Group 1. IARC Regulatory
- European Parliament and Council of the European Union (2019). Regulation (EU) 2019/1021 on persistent organic pollutants (recast), Annex I Part A. Official Journal of the European Union. Polychlorinated Biphenyls (PCB), CAS 1336-36-3, EC 215-648-1; manufacture, placing on the market and use prohibited, with an exemption for articles already in use at entry into force. EUR-Lex Regulatory
Frequently asked questions
Are there PCBs in my mattress?
No. PCBs were dielectric fluids and plasticisers, never sold as a mattress flame retardant, and they have not been manufactured in the United States since August 1977. ATSDR states that no known consumer product currently manufactured in the United States contains PCBs. Replacing a mattress does not change anyone's PCB exposure, and no credible certification scheme tests bedding for them because they are not used in the supply chain.
If PCBs were prohibited decades ago, why are they still in house dust?
Because they leave indoor spaces very slowly. Whitehead and colleagues estimated indoor half-lives of 5 to 18 years in California homes, which means a building can still be shedding what it absorbed before the ban. Harrad and colleagues measured median dust concentrations of 46 to 260 nanograms per gram across homes in the United States, the United Kingdom, Canada and New Zealand.
Where in a home do PCBs actually come from?
Mostly the building, and partly outdoors. PCB-containing caulk and elastic sealants, heat insulation and the capacitors in pre-1979 fluorescent light ballasts are the classic indoor sources, and ATSDR notes those ballasts can warm during operation and raise indoor air levels. DellaValle and colleagues found that levels in carpet dust from 1,187 US homes tracked outdoor variables such as developed land and population density, so a good share of what settles in a bedroom arrived from outside it.
What is actually worth doing?
Treat it as a dust problem rather than a product problem. Wet-cleaning and HEPA vacuuming address the pathway that matters, hand-washing before meals matters most for crawling toddlers, and retiring pre-1979 fluorescent light fittings removes a discrete source. If an older building is being renovated, get a professional assessment first: disturbing PCB-containing caulk or sealant is what turns a static source into an airborne one.
Related compounds
Embr is a sleep environment company researching and addressing the chemistry of the bedroom. Research and product development in progress.
Last reviewed 2026-07-25. If you find a factual error, contact us.