Feature Article

Antimicrobial Chemicals in Buildings: Hygiene or Harm?

August 2, 2007

Fear of infection is hardly a new phenomenon, but it seems to have risen to a fever pitch in recent years. Modern medicine appeared to have all but conquered infectious disease decades ago—but in the last three decades our society’s confidence in that victory has unraveled. Diseases like AIDS, anthrax, “mad cow disease,” severe acute respiratory syndrome, antibiotic-resistant tuberculosis, and bird flu have perplexed and challenged the medical establishment, and popular culture and the press have seized on reawakened fears of uncontrollable diseases, reporting on health emergencies around the globe with ever greater fervency. 

The market for antibacterial lotions, soaps, and wipes has exploded, and antimicrobial compounds are now common in other consumer items like shampoos, deodorants, shoes and apparel, and food-preparation and storage items, despite widespread evidence that these compounds often don’t work as advertised. But now even our buildings are getting in on the trend. The use of chemicals in building products, especially to kill mold, is centuries-old, but antimicrobial chemicals are proliferating in heretofore rarely seen places: furniture, flooring, wallcoverings, textiles, countertops, sunshades, doorknobs and push-plates, ductwork, and caulking. 

To say that cultural fears are driving these trends would be simplistic, however. In buildings, mold growth has long been known to compromise the structural integrity of buildings, and research over the last decade has increased concerns about mold’s effects on indoor air quality. Providing sanitary conditions in homes and commercial buildings alike has become a greater focus in preventing the spread of disease-causing pathogens. Hospitalization is a leading cause of 
death in the U.S.; among other hazards, infections acquired during hospital treatment kill more than 80,000 people annually (nearly twice the number of people killed in automobile accidents), leading to strong interest in antimicrobials from healthcare facilities. 

Some of these infections are caused by “superbugs,” pathogens that have developed resistance to multiple antibiotics used in medicine. (Antibiotics differ from antimicrobials in being specifically medicinal in nature and often being based on compounds derived from fungi and bacteria that are capable of killing fellow microbes.) Similar concerns associated with widespread use of antimicrobials suggest that bacteria could evolve resistance to them, becoming more deadly. The inherent toxicity of antimicrobial compounds—many of which are pesticides—also raises concerns that treatments to prevent disease could cause other problems.

This article examines applications of antimicrobials in buildings, asking whether they are warranted, and looking at how antimicrobials work. It also explores health and safety concerns and suggests ways to make buildings more hygienic, with or without antimicrobials.

Microbes—and Antimicrobials 

The Freedonia Group, a market research firm, projects that U.S. demand for disinfectant and antimicrobial chemicals will increase 5% annually to $930 million in 2009, up from $730 million in 2004. Those dollar figures represent growth in sales from 238 million pounds (108 million kg) in 2004 to 273 million pounds (124 million kg) in 2009. This growth is spread across several categories, with paints and coatings accounting both for the greatest volume compared with other categories, such as plastics and healthcare, and some of the strongest growth. Another product category, copper-based biocides, most commonly used as wood preservatives, accounted for another $245 million in sales in 2005, according to Freedonia, and shows similarly strong growth. (For more on protecting wood from insects and mold, which is not discussed in this article, see EBN Vol. 15, No. 8).