The materials red list (commonly shortened to simply “red list”) is a compilation of harmful-to-humans chemicals and materials compiled by the International Living Future Institute (ILFI) as part of its Living Building Challenge.
Products that contain chemicals on the red list must not be used if a building is to achieve Living Building status. There are seven performance areas, or “petals,” included in the Living Building Challenge and avoiding red list products falls under the Materials petal. This requirement is intended to ensure that buildings are not only conserving energy or limiting waste, but also protecting occupant health.
Development of the Red List
In addition to seeing chemicals on the red list phased out of production and use, ILFI hopes to influence the materials industry to be more conscientious about producing nonharmful-to-humans materials. While many products exist that may have an adverse effect on human health, the red list focuses on some of the worst offenders. It is subject to change based on emerging scientific knowledge, but currently includes:
- Chlorinated polyethylene and chlorosulfonated polyethlene
- Chlorofluorocarbons (CFCs)
- Chloroprene (neoprene)
- Formaldehyde (added)
- Halogenated flame retardants
- Hydrochlorofluorocarbons (HCFCs)
- Lead (added)
- Petrochemical fertilizers and pesticides
- Polyvinyl chloride (PVC)
- Wood treatments containing creosote, arsenic or pentachlorophenol
Alternatives to Red List Materials
Based on available market materials at a given time, ILFI does make some exceptions on a case-by-case basis. If builders are granted an exception, they must send a letter to the manufacturer of the red list material in question to explain that their purchase is not an endorsement and express a preference for the production of sustainable, non-toxic materials. There is also a “small component” clause that allows red list chemicals to be present in trace amounts. Under most circumstances, however, builders must seek out alternative products if they want a project to meet Living Building standards.
Red list alternatives do not necessarily cost more than standard materials. Typically the most difficult part about avoiding red list ingredients is finding appropriate substitutes and obtaining the necessary information from manufacturers. Below is a more in-depth look at some of the most common red list items:
PVC is a widely used plastic found in piping, electrical wire sheaths, and window frames. It contains phthalates, which are also components of flexible vinyl products, sealants, and finishes.
- There isn’t a great alternative to PVC wire sheaths. Metal-sheathed wiring (“armored” cable) can be used, but it is harder to work with and much more expensive.
- There are a few alternatives to PVC pipes. Metal (copper, steel, or ductile iron) pipes, which can be used for some purposes, are heavier, susceptible to corrosion, and typically more expensive to buy and install. Cross-linked polyethylene (PEX) and other related plastics are now being used to make flexible, convenient, and cheap pipes that do not contain PVC. Unfortunately, PEX cannot be recycled and its health effects have not been definitively studied. PEX degrades with sun exposure and may be more permeable to chemicals than other types of piping.
- Wood, aluminum, and fiberglass are common alternatives to PVC window frames. Wood requires additional maintenance, while aluminum frames should be used with some sort of thermal break to insulate the window and prevent condensation. Prices vary, and the environmental impact of manufacturing should also be considered.
- Avoid vinyl flooring, cords and hoses, shower curtains, artificial leather, pool liners, or paints made with phthalates. There are many alternative plasticizers.
CFCs and HCFCs are refrigerants used for air conditioning, heating, and, of course, refrigerators. They are also used in foams and aerosols.
- Hydrofluoro-olefin can replace these materials both as a refrigerant and a foam/aerosol to seal around windows. Carbon dioxide is a second alternative refrigerant, but unlike hydrofluoro-olefin, it requires a unique system from other refrigerants. Both carbon dioxide and hydrofluoro-olefin are cheaper than or comparable to standard refrigerants and both have low global warming potentials.
Halogenated flame retardants are found in upholstery, cloth window shades, and insulation.
- Non-halogenated flame retardants can replace halogenated ones without loss of function.
- Foam insulation can be used to avoid halogenated flame retardants found in many types of fiberglass insulation. It must be properly installed to avoid mold formation.
Formaldehyde is found in all sorts of products, from laminates to glues to wood products. Formaldehyde is often used as a binding agent in fiberglass insulation.
- Again, foam insulation is one way to avoid chemicals found in fiberglass insulation.
- Some fiberglass insulation brands use acrylic or rapidly renewable materials as a binding agent instead of formaldehyde.
- Recycled cotton insulation is another option. All of these alternatives are similarly priced to standard insulation.
Chloroprene is a synthetic rubber in water seals, gaskets, and geomembranes. Chlorinated polyethylene and chlorosulfonated polyethylene are found in geomembranes, roof membranes, and electrical sheaths and connections. Mercury is found in various types of light bulbs and lead can be present in paint, solders, or roofing. Look out for these and other red list chemicals on product labels. To be absolutely sure to avoid a certain chemical, some people choose to make their own building materials, sealants, or paints from ingredients like clay, oils, milk protein, and water, but these products do not necessarily perform exactly the same as commercially manufactured ones. Product directories (such as Declare, Green Depot, or Pharos) that emphasize ingredient transparency may be helpful in selecting red list alternatives.