Study Says Plastic Pipe Safe to Use for Transporting Drinking Water

Plastic pipe can be used to carry drinking water into new homes and apartments without threat to health or fire safety, a state report has concluded.

A preliminary environmental impact report (EIR) found “no unavoidable significant adverse effects” from substituting plastic for copper, cast iron or galvanized steel in hot and cold water lines in residential buildings.

Concern about the use of plastic piping centers on possible threats to public health from chemicals used in the plastic, pipe-joining material, or in the surrounding soil, which may be contaminated, and on how it may affect plumbers using the material who are exposed to fire or smoke.

The studies found that a few chemicals from plastic pipe and solvent cements leach into the drinking water, but to negligible degrees which are thought to pose no health risk.

Currently, plastic pipe is not allowed to carry water inside dwellings, and only two types--polyvinyl chloride and polyethylene--are allowed for cold water outside a dwelling.

Three other types are permitted for use as drain, waste and vent pipes in structures of two stories or less: polyvinyl chloride, acrylonitrile-butadiene-styrene, and chlorinated polyvinyl chloride.

Plumbing Code Changes

The California Department of Housing and Community Development is considering allowing plastic pipe to conform with changes in the Uniform Plumbing Code, which permits plastic pipe substitution for copper or galvanized iron pipe used to carry hot and cold water in residential buildings.

The EIR also found no significant adverse effects of plastic piping on housing prices, pipe manufacturing and plumbing employment, or on energy consumed in pipe manufacturing.

The agency is seeking public comment on the EIR for the next two months, at hearings in Los Angeles Sept. 26 and in Oakland on Sept. 27.

After the hearings, a final EIR will be prepared.

In two studies commissioned by the housing department, UC Berkeley analyzed chemicals that might be released by plastic pipe into drinking water, and the California Department of Health Services studied plumbers’ exposure to chemicals used to assemble plastic pipe.

Plumbers Safe

Plumbers installing the pipe would be safe unless they drank large quantities from an unwashed pipe.

Safety aspects of using plastic pipe were unclear, since plastic pipe was thought to decrease injuries from lifting and burns, but cause more hurried work by less trained individuals.

Studies of the effects of exposure to solvents and susceptibility to fire produced no conclusions indicating significant risk or danger.

If the changes are adopted at the state level, local jurisdictions also likely would seek similar changes in their codes.