Overview: Leaching Concerns

Chemical interactions between water and piping materials — typically oxidation — and the principles of osmosis mean all piping materials leach substances into water to some degree. Some materials are far safer than others, however. For example, lead pipes and fittings have emerged as a serious public health threat in homes, schools, and businesses with aging plumbing.

The leaching impacts of commonly used materials such as plastic and some metals are not as well known. Here’s an overview based on current research:

• Lead Leaching – Lead is an established neurotoxin and dangerous to human health; prolonged exposure can lead to a range of serious conditions. According to the Environmental Protection Agency, no level of lead exposure is safe. Water crises in communities across the country show the impacts of lead contamination and explain why recent infrastructure investments seek to replace lead with safer piping materials.
• Plastic Leaching – Research into leaching from plastic pipes has found scores of chemicals that pass into drinking water from plastic piping, fittings, and the solvents/glues used to bind them. These substances — including carcinogens such as benzene — leach from pipe walls over time, especially plumbing exposed to heat or hot water. Disinfectants used by water companies also can interact with plastic pipes, producing secondary chemicals.
• Copper, Iron, & Steel Leaching – These common pipe materials leach metal particles at levels generally regarded as safe.