Asthma and Respiratory Risks

People with asthma can be exceptionally sensitive to air contaminants, including those in ordinary cleaning products. A 2009 study led by Jonathan Bernstein, a physician and leading asthma and allergy researcher at the University of Cincinnati College of Medicine, measured worsening symptoms in asthmatic women after they had completed housecleaning tasks (Bernstein 2009).

A growing body of evidence suggests that using cleaning products can also cause asthma to develop in healthy people. A 10-country study of more than 3,500 individuals who were initially free of asthma found that nine years later, those who used spray cleaners at least once a week to clean their homes had a 30-to-50 percent increased risk of developing asthma during the study period (Zock 2007). This association was linked primarily to commonly used spray products such as air fresheners, glass cleaners and furniture cleaning sprays. The risk increased the more often people used sprays or the greater the number of different sprays used.

The research team calculated that with the widespread use of spray cleaners and the high level of asthma risk, one in seven cases of adult asthma could be attributed to the use of these products (Zock 2007).

Preliminary findings also suggest that fetal exposure to household cleaning supplies may affect respiratory health. In a series of studies on parents and children, scientists at three British universities determined that children born to women who frequently used cleaning supplies in their homes while pregnant had a higher risk of persistent wheezing and reduced lung function (Sherriff 2005; Henderson 2008). The increased risk of these respiratory symptoms persisted for at least eight years after in utero exposure and was independent of many other indoor air pollutant exposures and potential confounding factors.

Asthmagens or Respiratory Irritants

Asthmagens: ingredients that can cause or worsen asthma

• *2-Bromo-2-Nitropropane-1,3-Diol
• Alkyl Dimethyl Benzyl Ammonium Chloride
• Alkyl Dimethyl Ethylbenzyl Ammonium Chloride
• Didecyldimethylammonium Chloride
• Diethanolamine
• Dioctyl Dimethyl Ammonium Chloride
• Distearyldimonium Chloride
• *DMDM Hydantoin
• Ethanolamine
• Formaldehyde
• Glutaral
• Monoethanolamine Citrate
• Quaternium-15
• Quaternium-24
• Sodium Hypochlorite (Bleach)
• Sulfuric Acid
• Triethanolamine

* While not asthmagens themselves, these ingredients release formaldehyde, which is a recognized asthmagen.

Worker studies highlight asthma risk

Extensive studies show clear links between on-the-job exposure to cleaning supplies and the development of asthma in workers who had never shown previous signs of the disease (Medina-Ramon 2005, 2006; Rosenman 2006; Arif 2009; Quirce 2010; Zock 2010). Building custodians, teachers and health care workers are commonly exposed to cleaning supplies and are particularly afflicted by work-related asthma (Zock 2001; NIOSH 2004; Medina-Ramon 2005; Jaakkola 2006; Kogevinas 2007; Mazurek 2008). Many individuals recently diagnosed with asthma make a direct connection between exposure to certain cleaning products or chemicals and their condition. Studies have linked new cases of asthma to use of or exposure to spray cleaners, chlorine bleach sprays, disinfectants, air fresheners, drain cleaners, oven cleaners, furniture polish, carpet cleaners and floor waxing and stripping products (Nielsen 1999; Zock 2001, 2010; Medina-Ramon 2006; Obadia 2009; Quirce 2010; CDPH 2012).

A 2003 study led by Kenneth D. Rosenman, a professor of medicine at Michigan State University, found that 12 percent of the work-related asthma cases in four states were associated with exposure to cleaning products (Rosenman 2003). Four-fifths of the workers reporting work-related asthma linked to cleaning supplies had never suffered from the condition previously. Twenty-two percent of those afflicted worked as building custodians. In addition, seven of nine extensive epidemiological studies from several nations found an increased risk of asthma for people working as cleaners, with rates of asthma and asthma-type respiratory symptoms 1.5-to-2.5 times higher than in the general population (Rosenman 2006).

Chemicals can cause or worsen asthma

Several ingredients that are common in cleaning supplies are classified as asthmagens, meaning that they can cause asthma to develop in otherwise healthy people. In 2009, an EWG evaluation of 21 common school cleaners found that six of them emitted at least one of three common asthmagens into the air – formaldehyde, methyl methacrylate and styrene – when they were used as directed.

Many types of industrial chemicals can cause asthma. Those of greatest concern in cleaners include:

• Quaternary ammonium compounds, or “quats,” such as benzalkonium chloride, added as germ killers in antibacterial cleaning supplies and disinfecting air fresheners; they are also used as fabric softeners;
• Ethanolamines (mono-, di- and triethanolamine), commonly used to control product acidity (pH); they also act as detergents in many classes of cleaning products;
• Bleach (sodium hypochlorite) and ammonia (ammonium hydroxide), perhaps the most widely recognized cleaning ingredients in the world (AOEC 2012).

Many harsh acidic (low pH) or basic (high pH) cleaners aggravate asthma symptoms because they irritate the lungs. Moreover, if improperly mixed, bleach and acidic or ammonia-based cleaners can react to form extremely high concentrations of chlorine gas, which can cause a person to develop asthma after a single intense exposure (AOEC 2012). Other chemicals, like quats, bleach and ammonia, can cause asthma through allergic reactions that develop slowly after frequent, long-term exposures to lower concentrations of the substances (Bernstein 2006; AOEC 2012).

Impurities and chemical reactions

Many ingredients in cleaning products evaporate easily, and some can react with other contaminants in the air to produce new, asthma-inducing chemicals. Some of these volatile organic compounds, or VOCs, have been measured at levels up to 100 times higher than those found outdoors and can exceed safety limits established for industrial facilities (Nazaroff 2006; EWG 2009; Bello 2010).

Airborne reactions involving volatile organic compounds can produce ozone, a powerful lung irritant. Long-term exposure to ozone during childhood can cause permanent lung damage (Kunzli 1997; Gilliland 2001). While there is little conclusive evidence that ozone alone can cause asthma, the subject merits more extensive study.

Pine- and citrus-based cleaners contain a class of volatile chemicals known as terpenes, which indirectly increase asthma risks. Terpenes may also be found in air fresheners and cleaners that contain other essential oils for fragrance. They react with ozone to form formaldehyde, an asthmagen and known human carcinogen.

The California Air Resources Board recommends that consumers avoid using citrus and pine oil cleaners, especially on warm, smoggy, high-ozone days (CARB 2008). Ozone-forming volatile organic compounds and ozone-reactive terpenes from pine and citrus oils may act together to increase formaldehyde air pollution. The combined effects on air quality of cleaning products that release these chemicals have not been studied and are a cause for concern.

Childhood asthma is at an all-time high

Surveys by the federal Centers for Disease Control and Prevention have detected a dramatic increase in childhood asthma across the country over the past few decades. At present, nearly 1 of every 10 children in the U.S. – 9.3 percent of the U.S. population under age 18 – has asthma (CDC 2008), up from 7.5 percent in 1996 and just 3.6 percent in 1980 (CDC 2006). Childhood asthma is more common in African-American, Latino and low-income communities (CDC 2006; Babey 2007; Meng 2007). More asthma sufferers are being hospitalized than at any other time in American history, mirroring the documented trends in asthma prevalence (CDC 2006). The annual direct medical cost of asthma in children and adults for the year 2007 was estimated at $37 billion nationwide (Kamble 2009). Reducing in utero and childhood exposures to cleaning supplies that pollute the air with asthmagens and lung irritants may constitute an important investment in a healthy future.