The Red List

About the Red List

The Living Building Challenge (LBC) Red List represents the “worst in class” materials, chemicals, and elements known to pose serious risks to human health and the greater ecosystem that are prevalent in the building products industry. The International Living Future Institute (ILFI) believes that these materials should be phased out of production due to human and/or environmental health and toxicity concerns. While there are certainly other items that could be added, this list was determined by selecting items with the greatest potential impact if they were significantly curbed or eliminated from the building industry. ILFI worked with the Healthy Building Network and the Pharos Project to develop the original Red List in 2006.

Red List classes are added or retired with each new version of the LBC Standard. The revised chemical groupings that were established as part of the LBC 4.0 release more suitably categorize Red List chemicals by function, application within the building products sector and structural similarity. The chemical classes are described below, and the chemicals included in each group are detailed in the 2023 LBC Red List CASRN Guide. While all chemicals in the 2023 LBC Red List CASRN Guide fall within the list of chemical classes outlined in the Standard, not necessarily all chemicals in an LBC Red List Class are included in the enforceable CASRN Guide. The CASRN Guide itself is typically updated on an annual basis in January, and seeks to ensure that the Red List remains a leadership tool and reflects best available science.

The Watch List

With the release of the Living Building Challenge 4.0, ILFI also introduced the LBC Watch List. The intent of the LBC Watch List is to signal to manufacturers and project teams that ILFI has identified certain chemicals and compound groups for potential inclusion in the LBC Red List. The Watch List does not impact a product’s Declaration Status, nor the ability of project teams to use products that contain these chemicals on LBC projects. The LBC Red List CASRN Guide remains the enforceable screening list.

The Watch List fills an important gap in the identification and prioritization of chemicals for Red List inclusion. Substances on the Watch List may be additionally designated as “Priority for Red List Inclusion” (Priority) to indicate ILFI’s intent to add them to the Red List in future versions. A chemical must be designated as “Priority” for at least 12 months before it can be added to the Red List.

Priority designation provides a transparent “on-ramp” for the Red List, gives space and time for stakeholder dialogue about when and if to add those substances to the Red List, and provides manufacturers and consumers alike time to phase these chemicals out of products and design, contributing to the collective goal of a healthier materials economy. A chemical designated as Priority for Red List Inclusion will flag in light orange on a Declare label, but does not impact the product’s Declaration Status.

CASRNs may be added to the Watch List, or designated as Priority as part of ILFI’s quarterly update of its program resources. Substances will only be added to the enforceable Red List from the Priority List, and only as part of an LBC Red List Annual Update that occurs in January of a given year. Substances may also be “downgraded” from the Red List to Priority or Watch List or removed entirely from any list as part of the annual update process.

ILFI believes that this transparency and update schedule will result in a Red List that is regularly reviewed for alignment with best available science and market realities, and will push the industry further and faster towards a future free of toxic chemicals and materials.

Annual Updates to the LBC Red List

ILFI commits to a comprehensive annual review and update of the composition of the LBC Red List and LBC Watch List in order to reflect the evolution of voluntary restricted substances lists and global regulations as well as innovation of the building products manufacturing industry. Each annual update is supported by ILFI staff research and recommendations from a rotating advisory group whose membership consists of non-profit organizations, toxicology professionals and safer chemistry advocates. Using the Healthy Building Network’s Pharos project, ILFI identifies and adds chemical CASRNs to the LBC Red List chemical classes through both individual additions and class-based approaches of functional and structural similarity. Methodologies for inclusion utilize hazard screening based on GreenScreen Benchmark scores from full GreenScreen assessments and GreenScreen List Translator scores that are presented within Pharos, and a consideration of authoritative lists (lists based on a comprehensive expert review by a recognized authoritative body) in which a chemical is included as well as latest available environmental toxicology research and scientific reports. The result is a Red List and Watch List that affirm the precautionary principle in their intention and design, represent the collective knowledge of the industry in a unified and aligned voice, and emphasize their role as tools for advocacy.The currently effective LBC Red List and LBC Watch List are effective as of May 1, 2023. Prior to this, the lists were last updated in April 2022. The 2023 update to the Lists continues due diligence efforts to move chemicals to the Red List, through the 12-month minimum period of Priority for Red List Inclusion designation, and continues the Red List’s function as an effective screening tool of the pulse of the sustainable buildings and products sectors. In addition, movements of CASRNs between the Red List and Watch List provide ILFI the ability to make other significant changes for the subsequent annual update, a prioritization process that will be completed by ILFI as part of each annual update’s planning process. The updates to the list are summarized below. ILFI encourages its community of users and the greater industry to examine the 2023 LBC Red List CASRN Guide for specific CASRN updates and changes.

Notable Changes in 2023

Perfluorinated and Polyfluorinated Alkyl Substances (PFAS) / Perfluorinated Compounds (PFCs), In 2023, ILFI moved 5,938 per- and polyfluoroalkyl substances (PFAS) from the Priority List to the Red List. This continues the process of restricting PFAS as a class, and brings the total number of PFAS on the Red List to 10,819 compounds.  Please review the following resources for additional information regarding ILFI’s decision and guidance for program compliance.

Fact Sheet: The Living Building Challenge (LBC) Red List 2022 Updates: A Guide for Project Teams

Fact Sheet: The Living Building Challenge (LBC) Red List 2022 Updates: A Guide for Manufacturers

How annual LBC Red List changes affect Product Manufacturers

An active Declare label with a status of LBC Red List Free, LBC Red List Approved, or LBC Compliant at the time of specification (when the project team places the product order with the manufacturer) is sufficient documentation of product compliance with I13 Red List. This remains true even if a constituent chemical in the product is added to the Red List prior to the label’s expiration date. ILFI will encourage project teams to download the Declare label information at the time of specification.

Products in Declare will be evaluated against the LBC Red List version that is active when a manufacturer submits the product for its annual label renewal. At that time, a product with a Declare status of LBC Red List Free, LBC Red List Approved, or LBC Compliant may subsequently receive Declared status because a constituent chemical was subsequently added to the Red List and the product formulation wasn’t changed. ILFI will inform project teams that if they did not document the compliance status of the Declare label at the time of specification, they may cross-reference the Red List ingredient identified on the renewed Declare label with the contents of the Red List at the time of project registration, to demonstrate compliance.

Alkylphenols are a large family of organic compounds used in a wide variety of products, including cleaning products, beauty products, contraceptives, coatings, fragrances, thermoplastics, carbonless copy paper, and agrochemicals. Most concerns are focused on alkylphenol ethoxylates (APEs), which bioaccumulate and have been shown to cause endocrine disruption in fish. APEs are in cleaning products that end up in waterways from wastewater treatment effluent. Some alkylphenols, especially nonylphenol, are being phased out in Europe, and more research into their impacts is needed. A few governments with environmentally preferable purchasing programs restrict or ban APEs


Antimicrobials are a class of chemicals designed to kill or inhibit the growth of microbes. Antimicrobials are frequently used in soaps and building materials, including countertops, paints, and doorknobs. Nineteen antimicrobials were banned in soaps and bodywashes by the FDA in 2016. Antimicrobials used in building materials are regulated by the EPA as a pesticide, falling outside of the scope of the FDA’s ban. Antimicrobials are often used as a preservative in building materials, but the health benefits of their use have not been established or substantiated. Some antimicrobials are endocrine disruptors, and have been shown to impair learning and weaken muscle function.

Interest in building products with applied antimicrobial treatments has increased significantly during the recent global COVID-19 pandemic. While information regarding individual substances’ efficacy in controlling propagation of SARS-CoV-2 remains incomplete, “no evidence yet exists to demonstrate that products intended for use in interior spaces that incorporate antimicrobial additives result in healthier populations.” (COVID-19 Statement: Understanding Antimicrobial Ingredients in Building Materials, Perkins and Will and Healthy Building Network (2020)) ILFI continues to monitor the situation and commits to presenting current information about reported or potential human and environmental health impacts of antimicrobial substances as commonly used within the building industry and supporting its community of users in best utilizing this information in their own practice.


Asbestos is a mineral fiber that is used in a variety of construction materials for its strength and heat resisting capabilities. It is often found in wall insulation, vinyl floor coverings, paint compounds, roofing, heat-resistant fabrics, and automobile brakes. Exposure occurs as asbestos fibers are released into the air during use, demolition, work, building, or repair of asbestos-containing materials. Asbestos is a known human carcinogen, increasing risks of lung cancer, mesothelioma, and asbestosis.


Bisphenol A (BPA) and chemicals with structural or functional similarity, or BPA structural analogues (NTP 2017), are used to manufacture polycarbonate plastics, epoxy resins and other products. The plastics are used in many consumer products, such as drink bottles, DVDs, eyeglass lenses, electronics, car parts, and other products that must not break easily. Epoxy resins are used for lining food cans and water pipes, and for many sales receipts. Most recent testing in animal models and epidemiological studies in humans have shown that early life BPA exposure adversely effect neurological function and development, as well as adversely affect male sex organs (such as the prostate gland) in fetuses, infants, and small children (Inadera 2015). Most health organizations advise against the use of BPA for baby bottles and related infant products. BPA has also been found in breast milk demonstrating that this chemical has the potential to expose infant populations. BPA structural analogues such as Bisphenol S (BPS) are often less legally restricted and considered a “regrettable substitution” for BPA and pose many of the same risks as BPA.


California-banned solvents herein refer to the volatile organic compounds (VOCs) designated as Group II Exempt Compounds by South Coast Air Quality Management District (South Coast AQMD) Rule 102. This designation results from the US EPA’s use of the criterion of smog formation (defined as an organic compound’s contribution to the formation of ground-level ozone) to inform the regulatory definition of a VOC. As a result, US federal air quality regulations focus on VOCs that increase ground-level ozone concentrations, and exempt (meaning exclude) compounds with negligible reactivity. The basis of this determination is the ground-level ozone forming potential of ethane. Rules promulgated by South Coast AQMD (including Rule 1113 – Architectural Coatings, Rule 1143 – Consumer Paint Thinners and Multi-Purpose Solvents, and Rule 1168 – Adhesive and Sealant Applications) therefore serve as gap-filling measures, limiting exempt compounds’ product concentration and content by regulation when they are not regulated by the EPA. Additionally following these Rules that limit the percentage by weight of these exempt compounds in their respective product types, cyclic, branched, or linear, volatile completely methylated siloxanes (VMS) are not subject to the percentage by weight limit and are not included in the LBC Red List. Though the South Coast AQMD is an authority having jurisdiction (AHJ) overseeing specific sectors of the California building products market, its restrictions on VOCs are considered industry exemplars and have influenced a significant proportion of these product industries to conform to its standards.


PVC’s vinyl chloride monomer building block is a known human carcinogen, according to the US Department of Health and Human Services. In addition, PVC is a Persistent Organic Pollutant Source Material. Due to its chlorine content, PVC often contains other Red List ingredients, such as cadmium, lead, and phthalates. The manufacture and disposal of chlorinated polymers can result in the production of dioxins and disposal phases. Dioxins are some of the most potent toxins known to humans, with no known safe limit for exposure and a strong propensity for bioaccumulation. In addition, dioxins are highly persistent in the environment.

Chloroprene is a Persistent Organic Pollutant Source Material. Due to its carbon- chlorine base, chloroprene contributes to the creation of dioxins at different points in its life cycle (often manufacturing and/or disposal). According to the World Health Organization, dioxins are some of the most potent toxins known to humans, with no known safe limit for exposure and a strong propensity for bioaccumulation. In addition, dioxins are highly persistent in the environment.

Chlorinated Polyethylene (CPE) and Chlorosulfonated Polyethylene (CSPE) are Persistent Organic Pollutant Source Materials: due to their carbon-chlorine bases, these products contribute to the creation of dioxins and furans at different points in their life cycle (often manufacturing and/or disposal). According to the World Health Organization, dioxins are some of the most potent toxins known to humans, with no known safe limit for exposure and a strong propensity for bioaccumulation. In addition, dioxins are highly persistent in the environment. Similarly, furans accumulate in animal fat, concentrating as they travel up the food chain. Non-chlorinated polyethylene products are readily available in many product categories.


Chlorobenzene is used primarily as a solvent, a degreaser for auto parts, and a chemical intermediary for making other chemicals, so exposures are primarily a risk to workers making or using it. Most exposures are through inhalation of fumes. Short-term exposure can cause headaches, sleepiness, nausea, numbness, muscle spasms, and in extreme cases, unconsciousness. Chronic (long-term) exposure can cause increased signs of neurotoxicity (numbness, etc.) and irritation of the upper respiratory tract. In animals, chronic exposure has also caused kidney and liver damage. Chlorobenzene is broken down by sun and bacteria in the environment and does not accumulate in the food chain.


According to US EPA, the depletion of the Earth’s protective ozone layer by chlorofluorocarbons (or CFCs) is responsible for an increased incidence of skin cancer, cataracts, impairment of human immune systems, and damage to wildlife. CFCs have been banned from production in the United States since 1995.

Hydrochlorofluorocarbons (HCFCs) are potent ozone-depleting compounds. While less destructive than the now-banned chlorofluorocarbons, HCFCs are targeted for gradual phaseout by the US EPA, with a total ban going into effect in the year 2030. According to US EPA, the depletion of the Earth’s protective ozone layer is responsible for an increased incidence of skin cancer, cataracts, impairment of human immune systems, and damage to wildlife.


Formaldehyde is classified by the International Agency for Research on Cancer and the State of California as a known human carcinogen. Common health effects at low levels of exposure to this volatile organic compound include irritation and sensitization, and the compound also acts as an asthma trigger. Long-term exposure is associated with nasal cancers and leukemia.

Halogenated Fire Retardants (HFRs) are a broad class of flame retardants containing chlorine or bromine that have aroused concern due to their exponential accumulation in human beings in recent years. HFRs are persistent bioaccumulative toxins, meaning that they accumulate in organisms and the broader environment, often reaching alarmingly high concentrations as they travel up the food chain. In addition, certain halogenated products have shown evidence of harm to humans and other animal species. According to the Washington State Department of Ecology, for example, the toxicity endpoints of concern for Penta-PBDE include adverse effects on neurological development, reproduction, thyroid hormone disruption and possible liver toxicity.

HFRs include PBDE, TBBPA, HBCD, Deca-BDE, TCPP, TCEP, Dechlorane Plus, and other retardants with bromine or chlorine. Boron is not an HFR and is allowed. Many products, including virtually all foam insulations, contain HFRs.


Organotin compounds are a class of substances containing a bond between tin and carbon. Organotin compounds are used in the production of PVC, silicone rubber, and polyurethane. Exposure can cause memory loss, eye irritation, and liver damage. Certain organotin compounds are neurotoxins and acute exposure can be lethal. Organotin compounds are persistent in the environment and pose a threat to aquatic life at elevated concentrations. Animal studies have indicated organotin compounds might damage the immune and nervous systems.


Perfluorinated and Polyfluorinated Alkyl Substances, also commonly referred to as PFAS, are synthetic manufactured fluorine-containing chemicals that exist in many forms with many uses in building and consumer products. Perfluorinated Compounds, or PFCs, are a subset of PFAS. Building product applications of PFAS include roofing materials, paints and coatings, sealants, caulks, adhesives, carpets, and more, providing highly desirable functions such as weatherproofing, corrosion prevention, lubrication, friction reduction, and grease and water resistance. PFAS and PFCs are characterized by their carbon-fluorine bonds, which are some of the strongest bonds in all of organic chemistry. The wide range of uses for PFAS and PFCs increases the potential for human and environmental exposure and is magnified by their indefinite persistence in the environment and potential for bioaccumulation. While most individual PFAS have not been studied for their impacts to human and environmental health, their persistence contributes to bioaccumulation to levels that we know to be potentially harmful. In many cases, relatively safer non-fluorinated alternatives exist for these applications and many building product sectors are already making a transition to safer chemistries.


Mounting evidence from animal studies show the hormone-disrupting potential of phthalates, primarily orthophthalates, prompting the National Research Council to urge the US Environmental Protection Agency to pursue a “cumulative risk assessment” of this class of chemicals to determine their interactivity. Testing by the Centers for Disease Control and Prevention shows that phthalates are nearly ubiquitous in the US population, with highest concentrations in women and in children aged 6 to 11 years. The endocrine disrupting nature of phthalates has implications for childhood and reproductive development, as well as cancer incidence. The European Union and over a dozen countries have banned the use of phthalates in children’s products, as has the State of California.


PCB manufacturing in the United States stopped in 1977 but the compound is long-lasting in the environment (mostly in soils) around old manufacturing and disposal sites, in old electrical transformers and electrical devices, and in fish and their predators. PCBs make good coolants, lubricants, and insulators for electrical equipment of all kinds. They are known to cause cancer in animals and are probable human carcinogens, but exposure tends to be limited to people who worked in the electrical industry many years ago, lived close to manufacturing sites, and/or ate contaminated fish. Health effects also include acne-like skin conditions and neurobehavioral and immunological changes in children.


PAHs are a group of chemicals that are often produced by the incomplete combustion of organic material, particularly wood and fossil fuels. PAHs are commonly inhaled in tobacco smoke or smoke from indoor stoves fueled by wood or coal. They can also be ingested by eating burned meat. PAHs are also used to manufacture certain types of dyes. Exposure to PAHs is linked to lung, skin, and urinary cancer, and short-term exposure may cause vomiting and diarrhea. Almost every American has detectable levels of PAHs in their body.

SCCPs are most commonly used as lubricants and coolants in metal cutting and forming operations and are also used, along with MCCPs, as secondary plasticizers and flame retardants in plastics, such as PVC. Human exposure can be occupational, via inhalation of metalworking mists, or through contaminated food and dermal contact. Environmental exposure is usually from manufacturing activities, such as production, disposal, incineration, spills into waterways, and sewage effluent. SCCPs and MCCPs are persistent and very bioaccumulative in sediment. They have been found in marine mammals, other biota, and human breast milk in both industrial and remote areas. Toxic effects on mammals can include liver, hormone, and kidney damage that over a long term could lead to cancer in those organs.


Toxic heavy metals, including arsenic, cadmium, chromium (VI), lead (added), and mercury, pose a number of threats to health.

Arsenic is a carcinogen and can cause developmental issues.

The US Department of Health and Human Services and the International Agency for Research on Cancer have determined that cadmium is a known human carcinogen associated with lung cancer. Additionally, acute and long-term exposures can lead to lung and kidney damage, bone loss, and hypertension. In sufficient quantities, cadmium is lethal. Cadmium’s extreme toxicity means that overexposure can occur even when only trace amounts are present, such as during smelting and electroplating activities.

Chromium, primarily used in chrome plating materials, can cause breathing problems as well as nasal and lung cancer. Although chromium is a naturally occurring element and chromium III (trivalent chrome) is an essential nutrient, chromium (VI) (hexavalent chrome) can cause serious health issues, especially for factory workers who can inhale or ingest it during manufacturing. There has been concern about it in drinking water and, lacking EPA maximum allowable levels, the State of California set a public health goal for it. Chromium (VI) is used primarily for chrome plating of metals for decorative or protective finishes, making stainless steel, leather tanning, anti-corrosive agents for paints, and in textile dyes and pigments. Long-term or high-level exposure through inhalation can cause nasal irritation and ulcers, breathing problems, and nasal and lung cancer in unprotected workers. Ingestion can cause anemia and/or stomach tumors. Skin contact can cause skin ulcers and allergic reactions.

According to the Agency for Toxic Substances and Disease Registry, the environmental levels of lead have increased more than 1000-fold over the last three centuries, due almost exclusively to human activities. Lead exposure is damaging to virtually every organ and system in the human body, but is particularly damaging to the brain and central nervous system—profoundly so for young children and developing fetuses. Lead exposure is correlated with decreased IQ and delayed learning in children; scientific research has identified no safe level of lead exposure, and effects are irreversible.

According to the World Health Organization, mercury produces a suite of ill effects, including harm to the nervous, digestive, and immune systems, and even death. WHO lists children and developing fetuses as especially vulnerable to damage from mercury. Mercury bioaccumulates in the environment, eventually reaching concentrations thousands of times more intense than ambient levels.


VOCs are members of a large group of organic chemicals that can evaporate into the indoor air under normal temperature conditions and into the outdoor air, causing environmental impacts such as photochemical smog. Their health effects vary widely, from respiratory irritants to human carcinogens (such as formaldehyde), which is of concern since they are ingredients in many products in the built environment. On-site wet applied products (paints, adhesives, and sealants) are of particular concern because they can directly impact the health of installers who may not be using breathing or dermal protection, unlike in-factory wet applied materials that are (usually) applied with worker and environmental protections in place.

Unlike other items that appear on the Red List, (VOCs) are not banned outright. Wet-applied products (including coatings, adhesives, and sealants) applied on site must meet the following established emissions and/or VOC content standards: “Wet-applied products (including coatings, adhesives, and sealants) applied on site must have VOC levels below the South Coast Air Quality Management District (SCAQMD) Rule 1168 for Adhesives and Sealants or the CARB 2007 Suggested Control Measure (SCM) for Architectural Coatings, as applicable.”


Many conventional wood treatments introduce a litany of human health and environmental problems. The traits that make wood treatments effective at retarding rot and insect damage are also effective at damaging many other forms of life. According to the US Department of Health and Human Services, creosote exposure is associated with skin and scrotum cancer in humans, and liver, kidney, and gestational problems in laboratory animals. Inorganic arsenic is not only an acute toxin; it is a known human carcinogen. Pentachlorophenol is linked to liver and immune system damage in humans, and reproductive and thyroid damage in laboratory animals.

red list and watch list casrn guide

Previous versions of the LBC red list

The LBC Red List has moved to an annual update process as of 2021. Previous versions of the LBC Red List along with the dates they were active can be found in the ILFI Membership Dashboard in the “Resources” tab of the Living Building Challenge section.