“WARNING: This area contains chemicals known to the State of California to cause cancer and birth defects or other reproductive harm.”

Anyone who has been in California recently has seen this sign on numerous buildings. Proposition 65, which the state’s voters passed in 1986, requires this sign to be displayed on any structure where people are exposed to harmful chemicals listed in a state-run database. The warning signage usually refers to exposures to building contents, but the buildings themselves also can contribute. How can it be that even the greenest buildings in California still have this warning on them? While the building industry has begun considering environmental criteria in choosing building materials—such as recycled content, low levels of VOC emissions, no added formaldehyde, and FSC-certified wood—we have not yet tackled the matter of long-term health.

This issue came to the forefront for my firm, Anshen+Allen Architects, during early design work for several healthcare projects in California. We realized the Proposition 65 sign would be required. What irony­: The very buildings dedicated to providing care and upholding the medical field’s Hippocratic oath of “do no harm” are known to contribute to some of our greatest health problems? As designers, what could we do to avoid this contradiction? The design team was accustomed to asking product representatives if their goods are low-VOC, but what about asking if they contain teratogens—toxins that can cause birth defects? The designers quickly realized that there was no proven system of researching and testing which materials are potentially harmful to building inhabitants.

So Anshen+Allen teamed with chemists at McDonough Braungart Design Chemistry (MBDC), who could assist in determining whether an element such as “perfluorooctane sulfonate” was problematic (as well as how to pronounce it). Filtering criteria were developed to determine if building materials being considered for a project contain any chemicals that are:

• listed on the California Proposition 65 list

• classified as known carcinogens

• classified as known teratogens (toxins that cause birth defects) or mutagens (toxins that cause DNA defects in embryos)

• on the U.S. Environmental Protection Agency’s (EPA) list of “Chemicals of Concern,” which pose a risk to the public

• known to harm the adult reproductive system

The International Agency for Research on Cancer defines known carcinogens as “those substances for which the evidence from human studies indicates that there is a causal relationship between exposure to the substance and human cancer.” Good resources for known carcinogens are listed by the U.S. Department of Health & Human Services National Toxicology Program (ntp.niehs.nih.gov).

Unfortunately, a good centralized database of known teratogens and mutagens does not yet exist. However, there are ongoing studies by the EPA (epa.gov) and other governmental agencies to determine chemical classifications for them. For instance, the EPA recently began to consider including polybrominated diphenyl ethers (PBDEs), which commonly are found in building flame retardants, to its “Chemicals of Concern” list.

The California Office of Environmental Health Hazard Assessment (oehha.ca.gov) manages the Proposition 65 list, which is one of the world’s most comprehensive lists of chemicals that cause cancer, infertility, and birth defects. It is used by other governments and manufacturers to determine toxicity, and it is one of the easiest to use as a reference when reviewing products.

But even with the filtering criteria described above and the assistance of chemists on our healthcare projects, the Anshen+Allen design team discovered that investigating each material requires a significant investment of time. Often, full disclosure of material content is a major hurdle that stymies the entire process. Weighing the findings of dozens of reports and research studies that often are in disagreement also is a challenge. But many tools are being developed that hopefully will make this process easier. One example is the Healthy Building Network’s Pharos Project (pharosproject.net), an online tool that provides “the critical health and environmental data about the manufacture, use, and end of life of building materials specified and used every day.”

Factoring health criteria into material selection adds another layer of data collection and filtering on top of a process already overloaded with information. Design teams and owners usually filter building materials based on seven criteria: cost, code compliance (fire/smoke spread ratings), performance and durability, maintainability, comfort and safety (slip resistance), aesthetics, and ease of replacement. Adding environmental criteria (i.e., recycled content or FSC-certified materials) and health criteria makes material selection an exercise in database management.

With this in mind, we realized that instituting this process on an entire building would be an exercise beyond the project’s time frame and budget. Analyzing the hundreds of materials that go into the construction of a building would have been overwhelming, and we knew we could not just look at one choice for paint or flooring; we had to look at multiple options so we could compare them. How could our efforts have maximum impact while still keeping the exercise within a reasonable budget? Three concepts helped narrow the range of materials to research: contact, repetition, and spill-over. Would a person likely touch, smell, lick, or chew on the material? This is an important factor in a children’s hospital. In other words, would people likely come into contact with the material in a way that they could absorb toxins directly via mucous membranes? In hospital design, two rooms are repeated—inpatient rooms and exam rooms—so a second filter looked for repetition and the economy of scale that comes with it. The materials in these rooms also tend to spill over into the surrounding spaces, which also was analyzed. For example, a paint chosen for the patient rooms tends to be installed in the surrounding hallways, nurse stations, and other workrooms. With these three filters, we felt we could reasonably explore all the options—which still ended up being about 130 different finish materials for the patient and exam rooms collectively.

The next challenge was execution. The design team originally put together a long questionnaire with the intention of sending it to manufacturers. However, MBDC had experience with manufacturers’ nondisclosure agreements and convinced the team that this tactic would not get very far. Manufacturers are reluctant to share their ingredients or formulas, because they are seen as trade secrets. The team had to rely on material safety data sheets (MSDS) and other public information, which contain extremely good clues about the composition of materials. The chemists on the team then deduced the ingredients that were missing from the MSDS. Armed with this information, the team set about creating a scoring system to rank comparable materials. The system deducted points for every known toxin in a product, weighted by an estimate of the percentage of the material’s content that was toxic and the severity of the toxin.

We were surprised to discover that the worst offenders usually were the additives. For example, fabrics ranked OK on their own, but the flame retardants were toxic. Carpets were OK, but not the stain-resistant finishes. The flooring was OK, but not the sealers. This led the team to reduce the need for these coatings, specifying rubber floors or linoleum that doesn’t need sealing, or specifying carpets that are less likely to harbor microbes to avoid the need for antimicrobials.

The team was disappointed to discover that realizing the vision of a 100 percent toxin-free environment is not achievable in today’s market. Some of the classes of materials, such as epoxy paints, did not have a single high-scoring material. In cases like this, with no acceptable alternative, the team was forced to concede and specify the best option available, even if it had scored low.

Not unlike the decade-long process to reduce and eliminate VOC off-gassing materials, the process for bringing these kinds of health criteria into the mainstream could be slow. However, as designers, pushing the manufacturers and asking the right questions can create a domino effect. Already, we are having an impact and noticing that blank stares are turning into intelligent discourse about a material’s make-up. Hopefully, one day we will see a different kind of sign on our structures.

“GREAT NEWS: This area contains only products the State of California considers to be extremely beneficial to your health.”

Tyler Krehlik is an associate principal at Anshen+Allen ( anshen.com ) in San Francisco.