Water dispensers, whether large bottled units or plumbed-in systems, offer a convenient source of readily available drinking water. However, a water dispenser is not a maintenance-free appliance, and neglecting its upkeep can introduce potential biological and chemical hazards. Understanding these risks is necessary to ensure the water dispensed remains clean and safe for consumption. Safety concerns primarily revolve around microbial growth within internal components and the possible leaching of chemicals from plastic parts.
How Microbial Contamination Occurs
The enclosed environment of a water dispenser’s internal reservoir and tubing presents conditions that can promote the growth of microorganisms. This contamination often begins with the formation of a biological film, known as biofilm, which adheres to the dispenser’s surfaces. Biofilm provides a protective layer, shielding the organisms from the low levels of disinfectant that may be present in the water supply.
Water that sits in the dispenser’s cold tank or internal lines for an extended period is considered standing water. This lack of circulation and the ambient temperature of the room create an ideal breeding ground for opportunistic pathogens. Studies frequently detect bacteria such as Pseudomonas aeruginosa and various coliform bacteria in poorly maintained dispensers, which can pose a risk, particularly to people with compromised immune systems.
Contamination is not limited to the internal components; external surfaces play a significant role in spreading germs. The spigots, dispense buttons, and drip trays are high-touch areas that frequently come into contact with hands, cups, and airborne particles. This external contamination can migrate to the water as it is dispensed or back into the reservoir, highlighting the need for routine external cleaning.
Understanding Chemical and Material Safety
Beyond microbial issues, the materials used in the construction of water dispensers and bottles can introduce chemical concerns. Many plastic components, such as reusable water cooler bottles, are traditionally made from polycarbonate plastic containing Bisphenol A (BPA). BPA is a chemical that may leach from the plastic into the water, a migration often accelerated by heat or when the plastic begins to degrade.
Phthalates are another group of chemicals often added to plastics to increase their flexibility. These chemicals are also known to leach into the water. Because of these concerns, many manufacturers now advertise “BPA-free” plastics or utilize stainless steel reservoirs and components.
When selecting a unit, choosing one with stainless steel parts or verifying the food-grade quality of the plastics is a prudent step. Furthermore, if internal components like heating elements or pipes degrade, heavy metals may leach, though this is uncommon in modern, well-maintained units.
Essential Cleaning and Maintenance Practices
Maintaining a strict cleaning schedule is the most effective way to mitigate both microbial and chemical risks associated with water dispensers. For bottled units, a deep internal sanitization is typically recommended every three to six months, depending on the manufacturer’s guidelines and the frequency of use. Plumbed-in, or point-of-use, units often require internal sanitization less frequently, generally every six months, but filter changes must be performed regularly as specified by the manufacturer to ensure water quality.
The internal cleaning process involves draining the system and circulating a sanitizing solution through the reservoir and lines. Common, effective household sanitizers include a diluted bleach solution or white vinegar. The solution should be allowed to sit for 10 to 15 minutes before being thoroughly flushed with fresh water.
External surfaces, including the spigots, the dispensing area, and the drip tray, should be wiped down daily with a food-safe sanitizing wipe or spray, paying special attention to areas touched most often.
When replacing a water bottle on a bottled unit, users should first wash their hands and carefully wipe the neck of the new bottle to prevent introducing contaminants into the reservoir. For units that dispense hot water, a physical safety feature, such as a child safety lock, is incorporated to prevent accidental scalding. These mechanisms must be checked periodically to ensure they are functioning correctly.