Could household cleaning products end up dirtying indoor air?

RTÉ News​

03-06-2025

Analysis: When we clean, the goal is to remove dirt and germs, but in the process, we often introduce harmful chemicals into the air
Household cleaning products are among the most widely used consumer goods, found in nearly every home. Their use, along with disinfectants, saw a marked rise during the pandemic.
As early as 3000 BCE, ancient Egyptians used soda as a detergent, and Romans employed urine (which contains ammonia) for textile cleaning. While using chemicals for cleaning is not new, today's widespread use of these products, containing of a wide range of synthetic compounds has introduced new risks. Regulations like the 2008 Classification, Labelling, and Packaging regulation in the EU have aimed to improve safety. However, more awareness and action are needed to protect public health.
When we clean, the goal is to remove dirt and germs. But in the process, we often introduce harmful chemicals into the air. Cleaning products, including disinfectants, frequently contain surfactants, acids, bases, and synthetic fragrances. Historically, some formulations included concerning substances like chloroform and endocrine-disrupting chemicals such as phthalates and cyclosiloxanes, though EU regulations have significantly restricted these substances in consumer products to concentrations below 0.1%. Awareness however is warranted since there may be risks associated with cumulative accumulation of some of these chemical.
When applied to surfaces, these products gradually emit volatile and semi-volatile organic compounds (VOCs, SVOCs). These emissions can also trigger the formation of fine particulate matter by reacting with other chemicals in indoor air. The result is a mix of pollutants that lingers in the air, long after cleaning is done.
For example, spraying cleaning products can release fine particles and gases directly into the air. While larger particles settle quickly on to surfaces, contributing to emissions from surfaces, the smaller particles remain suspended and can be inhaled. Regular use of spray based cleaning products is considered a greater risk than other types of cleaning products, leading to higher frequency of respiratory symptoms.
Even "green" or "natural" products, often marketed as safer alternatives, can emit harmful chemicals. Essential-oil-based cleaners, for instance, contain terpenes, like limonene. Limonene is a common fragrance ingredient and one of the most abundant indoor pollutants. We associate it with that fresh lime or lemon smell. Limonene use must comply with allergen labelling requirements in the EU. Limonene reacts with ozone in the air to form formaldehyde and other secondary pollutants. The concentrations of the pollutants thus reached may reduce at a very slow pace, depending on the ventilation in homes.
These reactions can also lead to the creation of particulate matter and photochemical smog indoors, further degrading air quality. Studies have found that cleaning in the afternoon, when outdoor ozone levels are higher, can worsen this effect, with pollutant concentrations remaining elevated for hours.
The health implications of exposure to cleaning products are well-documented. Professional cleaners endure a lot higher exposure due to their occupation. This has been linked to increased risks of asthma, rhinitis, and respiratory symptoms.
At home, even though the exposure is lesser, regular use of cleaning products have been associated with asthma onset and asthma-like symptoms. Skin contact with cleaning agents can cause irritation, especially when protective clothing is not used.
For home scenarios, a 90-minute cleaning session, once a week, may not raise a concern about chronic exposure. During the cleaning, there can be risks related to acute exposures, even to some trace elements in the products or due to secondary formation of chemicals. The first symptoms are often irritation of the respiratory tract (nose and throat) and eyes.
From RTÉ Radio 1's The Ray D'Arcy Show, Laura de Barra's guide to deep cleaning your kitchen
Children are particularly vulnerable. Exposure to cleaning products has been known to affect lung function, cause airway obstruction, and trigger inflammation in children. Spray cleaners, in particular, can be especially harmful due to their ability to disperse fine particles and chemicals in a form that can be breathed deep into the respiratory system.
While "green" cleaning products are often marketed as safer, research shows that they are not always free from harmful emissions. However, fragrance-free products tend to emit fewer VOCs compared to conventional cleaning products.
Improving indoor air quality requires not only better product formulations but also increased public awareness. Clear labeling, education on safe cleaning practices, and stricter regulations on hazardous substances can all help. By making informed choices and adopting safer cleaning habits, we can reduce our exposure to harmful chemicals and create healthier indoor environments for ourselves and our families.
Here are some specific, practical steps to follow:
Read Labels: Look for products with clear ingredient lists and avoid those containing essential oils, phthalates and formaldehyde.
Choose: Prefer fragrance-free or low-VOC cleaning products and not just "natural" products. At home, you can also choose ready-to-use products instead of ones that need to be diluted before every use.
Avoid Sprays: Use liquid or wipe-based cleaners instead of sprays to minimise inhalation risks.
Protection: Wear gloves while cleaning and use appropriate respiratory protection. The latter is especially important for professionals.
Ventilate: Open windows and/or doors, use exhaust fans during and after cleaning to dilute the indoor pollutants.
Timing Matters: Where possible, clean when the space is not occupied and finish several hours beforehand to allow the pollutants to dissipate. For schools and offices, this could mean cleaning after hours. At home, clean in the morning when outdoor ozone levels are lower to reduce the formation of secondary pollutants.