Volatile organic compound — banned solvent

Carbon tetrachloride in the bedroom

By — 19-year firefighter and entrepreneur. Published July 2026.

Carbon tetrachloride is a fully chlorinated one-carbon compound historically used as a solvent, fire extinguisher fluid, and chemical feedstock. IARC classifies it as Group 2B (possibly carcinogenic). It is banned under the Montreal Protocol as an ozone-depleting substance and has been largely eliminated from consumer products since the 1970s. Its bedroom relevance is limited — it is a legacy environmental contaminant that may be present at trace levels in ambient air and near contaminated sites.

Carbon tetrachloride — Embr Bedroom Chemistry Atlas

At a glance

Chemical familyChlorinated solvent — ozone-depleting substance
CAS number56-23-5
ClassificationIARC Group 2B (possibly carcinogenic to humans); Montreal Protocol ozone-depleting substance (phased out); EPA Group B2 (probable human carcinogen)
Where you encounter itLegacy contamination near dry cleaning and industrial sites; trace levels in ambient air (declining); historical uses: fire extinguisher fluid, dry cleaning solvent, grain fumigant
Sleep micro-environment relevanceMinimal direct bedroom relevance. Carbon tetrachloride has been eliminated from consumer products since the 1970s-1980s. Trace levels in ambient air are detectable but extremely low and declining globally

Regulatory & certification status

European UnionREACH Annex XVII restricts use. Banned from consumer products. CLP Carc. 2 (H351). Ozone Regulation (EC) 1005/2009 implements Montreal Protocol phase-out. Regulatory
United StatesEPA MCL for drinking water: 5 µg/L. Clean Air Act hazardous air pollutant. California Proposition 65 listed (cancer). Banned from consumer products. Regulatory
CanadaCEPA Schedule 1. Montreal Protocol implementation. Drinking water guideline: 2 µg/L. Regulatory
InternationalIARC Group 2B (possibly carcinogenic). Montreal Protocol — ozone-depleting substance, production phased out. Global atmospheric levels declining. Regulatory

What it is

Carbon tetrachloride (CCl4) is the simplest fully chlorinated hydrocarbon — four chlorine atoms on a single carbon. It was widely used as a dry cleaning solvent, fire extinguisher fluid, refrigerant, grain fumigant, and chemical feedstock. Its production for dispersive uses was phased out under the Montreal Protocol (1987) because it is an ozone-depleting substance. IARC classified carbon tetrachloride as Group 2B based on sufficient evidence of carcinogenicity in animals (liver tumours) and inadequate evidence in humans. It is highly toxic to the liver and kidneys. Global atmospheric concentrations have been declining since the phase-out but remain detectable.

Where it shows up in bedding

Carbon tetrachloride has no use in modern bedding products and was never a mattress material. Its bedroom relevance is limited to trace ambient air contamination and potential vapour intrusion near contaminated industrial sites. Unlike some other chlorinated solvents (trichloroethylene, perchloroethylene), carbon tetrachloride is rarely implicated in residential vapour intrusion because its production and use have declined so substantially. For most bedrooms, carbon tetrachloride is not a meaningful exposure source.

The Embr Exposure Ledger: Carbon tetrachloride

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.

This compound appears in 6 of the Embr Exposure Ledger’s 10 exposure datasets.
Is it in the air?
In U.S. outdoor air: about 2.9 in a million added lifetime cancer risk.Source: EPA AirToxScreen (2020) — modeled ambient air-toxics concentrations and risk
At what level would it matter?
Published benchmarks exist: an inhalation reference concentration of 0.1 mg/m³ (EPA IRIS) and a residential indoor-air screening level of 0.47 µg/m³, set on a cancer endpoint (1-in-a-million excess lifetime risk). A screening level is the concentration at which EPA would look further, not a boundary between safe and harmful. The ledger holds no measured sleeping-environment concentration for this compound, so there is nothing here to compare the benchmark against — it tells you what would matter, not what is in any room.Source: US EPA, Regional Screening Levels (RSL) Summary Table — consolidated toxicity values from IRIS, PPRTV, ATSDR, Cal EPA and OPP
Who releases it?
39 US facilities reported releasing it in 2024 across 13 states and territories; 29 Canadian facilities have reported it (1993-2024). These are self-reported quantities leaving a facility, not levels anyone encountered, and the two national programs are not added together — they use different reporting thresholds.Source: US EPA, Toxics Release Inventory (TRI) Basic Data File, 2024 reporting year; Environment and Climate Change Canada, National Pollutant Release Inventory (NPRI), releases 1993-present
Does the law flag it?
Listed under California Proposition 65 for cancer since 1987. Carries an EU-wide binding classification as carcinogenic (category 2). That classifies the substance itself; it does not restrict any product.Source: California OEHHA Proposition 65 List (Safe Drinking Water and Toxic Enforcement Act of 1986)Source: EU CLP Annex VI

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.

Citations

  1. IARC (1999). Carbon Tetrachloride. IARC Monographs Vol. 71. Source Regulatory
  2. ATSDR (2005). Toxicological Profile for Carbon Tetrachloride. Source Regulatory
  3. UNEP. Montreal Protocol on Substances that Deplete the Ozone Layer. Source Regulatory

Frequently asked questions

  • Is carbon tetrachloride still used?

    Carbon tetrachloride is still produced in limited quantities as a chemical feedstock (to make refrigerants and other chemicals), but all dispersive uses (solvents, fire extinguishers, grain fumigants) have been eliminated under the Montreal Protocol. You will not encounter it in consumer products.

  • Can carbon tetrachloride contaminate a home?

    Only if the home is located near a contaminated industrial site where carbon tetrachloride was historically manufactured or used in large quantities. Vapour intrusion from contaminated groundwater is theoretically possible but rare for this compound. If you suspect industrial contamination near your home, contact your state environmental agency for testing.

Related compounds

Embr is a sleep environment company researching and addressing the chemistry of the bedroom. Research and product development in progress.

Last reviewed 2026-07-07. If you find a factual error, contact us.