A Boil Water Advisory (BWA) is a public health warning indicating that tap water may be contaminated with pathogens. The primary danger is accidental ingestion, not skin contact. For most healthy adults, showering with tap water is acceptable during an advisory, provided specific precautions are followed to prevent the water from entering the body.
Why Contaminated Water Poses a Risk
The pathogens potentially present in contaminated water, such as bacteria, viruses, or protozoa, primarily target the gastrointestinal system. If swallowed, these microorganisms can cause illnesses characterized by symptoms like diarrhea, vomiting, and abdominal cramps. The skin is an effective barrier and does not absorb these waterborne pathogens, meaning the risk of infection through simple skin contact is negligible.
The two main exposure routes during a shower are accidental ingestion and the inhalation of water aerosols. Ingestion can occur easily if water splashes into the mouth or nose during regular showering or hair washing. Inhalation risk increases because showering creates a fine mist of water droplets, or aerosols, which can carry contaminants deep into the respiratory tract. Hot water is particularly problematic because it generates more steam and fine aerosols than cooler water.
Essential Precautions for Showering Safely
To minimize risk, healthy adults should take short, lukewarm showers with a gentle flow. Using lower water pressure and reducing the temperature limits the production of steam and fine aerosols, which carry the highest risk of inhalation. Avoid directing the shower spray directly at the face and keep the mouth and eyes tightly closed while under the water.
Individuals with open surgical wounds, recent skin abrasions, or a compromised immune system should exercise caution. For these vulnerable populations, and for infants and young children, a full shower or bath should be avoided entirely. Instead, use a sponge bath with bottled water or tap water that has been boiled and cooled.
Managing Other Household Water Activities
Other personal hygiene activities require different levels of precaution due to their connection with ingestion. Brushing teeth demands the use of bottled water or water that has been brought to a rolling boil for at least one minute and then cooled. Untreated tap water should never be used for this purpose because accidental ingestion is likely.
Handwashing can be done safely with tap water and soap. The key is to ensure no water is swallowed, and hands should be completely dried afterward. If hands are being washed immediately before preparing food, use bottled or previously boiled water for the final rinse.
When bathing infants or pets, the risk of accidental ingestion is high because they may splash or drink the water. Sponge bathing with cooled, boiled water is the safest option for babies. Pets should also be provided with bottled or boiled and cooled water for drinking until the advisory is lifted.