Drinking water directly from a standard garden hose is generally not considered safe. The water that enters the hose from your outdoor spigot is the same quality as the water in your home’s plumbing, but the hose itself acts as a secondary system that introduces multiple sources of contamination. Water quality can degrade significantly within the hose due to the materials it is made from, microbial growth, and the metal components used for connection. Garden hoses are not regulated as drinking water dispensers and are often manufactured with industrial-grade materials not intended for human consumption.
Chemical Leaching from Hose Materials
Most common garden hoses are constructed from polyvinyl chloride (PVC), a plastic that requires chemical additives to make it flexible and durable. These additives are not chemically bound to the plastic and can leach into the water, particularly when the hose is exposed to heat or direct sunlight. This chemical migration is the most significant non-biological risk associated with drinking from a standard hose.
One common group of plasticizers is phthalates, which are used to give PVC its characteristic flexibility. Phthalates are known endocrine disruptors. Water left to sit in a hose exposed to the sun can reach high temperatures, greatly accelerating the rate at which these compounds, along with Bisphenol A (BPA), transfer into the stagnant water. Testing has found levels of BPA and phthalates in hose water that exceed safe drinking water limits.
Microbial Risks of Stagnant Water
Beyond the chemical concerns, the interior of a garden hose provides an ideal environment for the growth of microorganisms. When water remains stagnant inside the hose, especially when warmed by the sun, it quickly becomes a breeding ground for bacteria and the formation of biofilm. Biofilm is a complex matrix of microorganisms that adheres to the inside surface of the hose, protecting the bacteria from disinfectants and allowing them to multiply.
This stagnant, warm water environment can harbor potentially pathogenic bacteria, including Legionella species, which cause Legionnaires’ disease, a serious form of pneumonia. Studies have shown that Legionella densities within garden hoses can be comparable to those found in water sources linked to outbreaks. While the primary risk from Legionella is inhalation of contaminated aerosols, consuming water containing these microbes is also a risk.
The Danger of Metal Fittings and Connectors
A third source of contamination comes from the metal hardware used to connect the hose to the spigot and the nozzle. Standard brass fittings and connectors often contain lead to improve their machinability. Although regulations have limited lead content in plumbing for potable water systems, these limits do not always apply to outdoor hoses and fittings, which are typically unregulated as drinking water components.
When water sits in contact with these brass components, especially in warm, stagnant conditions, the lead can leach into the water. Tests have shown that standing water in a hose can contain lead levels exceeding the Environmental Protection Agency’s action level for drinking water. This poses a particular concern for children, as lead is a neurotoxin that can cause cognitive impairment. Choosing fittings made from materials like stainless steel or lead-free brass is necessary to mitigate this risk.
How to Choose a Safe Drinking Water Hose
For applications where you need to use a hose for drinking water, such as in an RV or for a temporary outdoor kitchen, you must choose a product specifically labeled as “drinking water safe.” These hoses are typically made from materials that comply with strict health standards, often utilizing polyurethane or specialized, food-grade PVC compounds that do not contain harmful plasticizers like BPA or phthalates.
The most reliable assurance of safety is to look for a certification mark such as NSF/ANSI Standard 61 on the packaging. This certification indicates the product has been tested and meets standards for materials that come into contact with drinking water. Even with a certified drinking water hose, you should always flush out the water that has been sitting inside to remove any contaminants that may have leached over time or any concentrated bacteria. Storing the hose in a shaded or cool location will also help to reduce the potential for both chemical leaching and microbial growth.