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When building or purchasing a home, consumers ask whether
CPVC piping or traditional copper plumbing is best for hot and cold potable
water supply. This Builders Websource Tech Note explores the benefits and
considerations of both CPVC and copper plumbing for domestic water supply
use. Applications, environmental considerations, lifecycle costs,
limitations and health effects are examined. Results from over 100 pages of
research are condensed into this handy authoritative guide for professionals
and consumers alike.
Over the years, a range of materials have been used to
deliver potable water for industrial and residential uses. Early on,
galvanized steel pipe was used for water distribution. This suffered from
high cost of installation and internal corrosion, which after 30-40 years of
use eventually constricts the water flow to the point of being ineffective.
For several decades now, copper tubing has been the mainstay and preferred
method of water distribution inside residential structures, accounting for
approximately 85% market share in new construction. When installed properly
and when the water supply is non-acidic, copper plumbing has proven the test
of time as a reliable and safe delivery vehicle for potable water.
However, in recent years, new materials have entered the market to
challenge copper's dominance. PB, or Polybutylene tubing was popular for its
low cost of installation compared to copper. However, excessive failures in
the field led to class action lawsuits and the ultimate banning of PB in
1995. Over the years, a better substitute has emerged called CPVC, or
chlorinated polyvinyl chloride. B.F. Goodrich (now called just "Goodrich")
holds multiple patents on the resins, which it licenses to pipe
manufacturers under the name FlowGuard Gold®. (As of June 2001, FlowGuard
Gold® is now marketed under the Noveon name). CPVC is typically beige or
light grey in color and is now approved by virtually every model building
code for use in residential water distribution systems.
Compared to copper, CPVC appeals to some homebuilders due to its
lightweight nature, ease of installation and lower overall installed cost.
Often, these savings can be passed on to the consumer in terms of overall
lower prices for homes.
However, as with any new material that challenges the proven performance
of its predecessors, CPVC is not without its critics. Many professional
plumbers avoid installing CPVC for fear of callbacks or lawsuits. With the
PB scare still in recent memory, many do not understand the pros and cons of
CPVC vs. copper plumbing, and therefore stay away for fear of the unknown.
This Tech Note is designed to demystify CPVC and help to educate
consumers and professional under what conditions CPVC should be used, while
pointing out the important considerations of both materials.
Benefits and Considerations of CPVC Plumbing
Benefits of CPVC pipe include:
Resistance to corrosion and abrasion
Smooth bore for improved flow and reduces water noise
High impact strength
Easy, cost-effective installation
Competitively priced vs. copper
Lightweight reduces heavy lifting
Less subject to jobsite theft
Self-insulating to minimize thermal loss
Integral flame retardancy and low smoke density
Pressure rating of 100 PSI @ 180° F, 400 PSI at 73° F
Short-term pressure rating > 200 PSI
Flexibility virtually eliminates water hammer (no water hammer
arrestors required under normal conditions)
Inert to acidic soils and corrosive water supplies
Can be buried directly under slabs with no chemical interaction with
Eliminates pressure leaks at solder joints
Easy for DIY'ers
Virtually no sweating or condensation
Relative price stability over time
Considerations of CPVC pipe include:
Generally limited to 1/2" to 2" Copper Pipe Size
Some complaints of "plastic taste" in water
Fittings and pipe subject to cracking or damage on job site if dropped
or stepped on
Solvents used to join fittings and pipe contain volatile organic
compounds (VOCs) which are known pollutants and require proper ventilation
Subject to melting during a fire (becomes viscous at 395° F)
High coefficient of expansivity (1 inch in 50 feet over 50-degree
temperature change) (3.4x10-5 in/in/°F)
Inner CPVC pipe surface can support the growth of bacteria including
legionellae pneumophilia (ref. A Comparison of the Colonization by
Bacteria of Copper and Other Materials Commonly Used in Plumbing Systems
with Special Reference to Legionella Pneumophila)
Due to ease of installation, CPVC is sometimes installed by less
skilled labor, potentially resulting in more frequent incidence of
Subject to cracking during earthquakes
Generally requires a 24-hour cure period before pressurizing with
Standards and code compliance (eg. FlowGuard Gold®)
Meets or exceeds ANSI/NSF Standard 61 for potable water
Meets of exceeds all ASTM and industry standards
Meets model building codes, BOCA National Plumbing Code, National
Standard Plumbing Code, Standard Plumbing Code, Uniform Plumbing Code,
CABO 1- and 2-Family Dwelling Code, Canadian Plumbing Code
Health Effects of CPVC
Much has been written about the potential health effects of
residual vinyl chloride monomer, or RVCM which is found in trace amounts in
plastics containing Polyvinyl Chloride, including CPVC and PVC pipe.
Proponents and detractors alike continue to debate the long-term health
impact due to extended exposure to RVCM.
VCM is made by heating ethylene
dichlroride (EDC) to 700 degrees F in the presence of oxygen. VCM is used to
produce PVC resins which are used to make pipe and other materials using a
process known as polymerization. During this process, most, but not all of
the VCM is consumed. Trace amounts remain trapped in the PVC resin where it
either outgasses into the atmosphere, or migrates into food or drink stored
in containers or pipes made of PVC. This remaining chemical is residual
vinyl chloride monomer, or RVCM.
For the record, all national building codes have approved CPVC for
potable water distribution in the United States and Canada. These approvals
have come after extensive testing and quality control standards which guide
the production of these products. Today's product meets stringent
ANSI/NSF-61 standards for water quality control. There is no scientific
evidence that CPVC tubing made to current US standards is in any way harmful
However, there is little argument that extended exposure to VCMs which
exceed government standards, can lead to neurological and liver effects as
well as cancer, such as angiosarcoma - a normally rare form of liver cancer.
As long ago as 1961, Dow Chemical researchers concluded that exposure to
Vinyl Chloride levels greater than 50 ppm were considered potentially
Generally, high exposure levels of VCM have been historically limited to
workers who produced CPVC and PVC products on a daily basis. In some cases,
there have been increased incidences of rare illnesses clustered in areas
near manufacturing facilities using vinyl chlorides. The shroud of secrecy
surrounding VCM broke when, on January 23, 1974, B.F. Goodrich responsibly
reported that it had traced three fatal cases of angiosarcoma among workers
at its Louisville, Kentucky plant.
In a 1998 Houston Chronicle article by Jim Morris called "Toxic Secrecy,"
the ill effects of long-term exposure to VCM is well documented.
Furthermore, the US Environmental Protection Agency (EPA) produced a revised
fact sheet on January 27, 1998 on Vinyl Chloride as part of the National
Primary Drinking Water Regulations.
The EPA report, which is intended to be an unbiased information source,
states that "vinyl chloride [can] potentially cause neurological effects
from acute exposure at levels of 0.002 mg/L."
"Drinking water levels with are considered 'safe' for short-term
exposures: For a 1--kg (22 lb.) child consuming 1 liter of water per day: a
one- to ten-day exposure of 3 mg/L; upto a 7-year exposure to 0.01 mg/L."
"Major human exposure will be from inhalation of occupational atmospheres
and from ingestion of contaminated food and drinking water which has come
into contact with polyvinyl chloride packaging materials or pipe which has
not been treated adequately to remove residual monomer."
Granular activated charcoal and packed towared aeration are considered
the best technologies available for treatment of water containing RVCM.
Other findings reveal that extended exposure to VCM has been linked to a
hand disability called acroosterolysis, although this has been generally
limited to people who routinely cleaned production reactors. It should be
noted, however, that according to ASTM Standard F402-88--and underscored by
the Plastic Pipes and Fittings Association (PPFA) User Bulletin 8-82--gloves
should be worn when handling CPVC pipe, although many installers fail to
follow these guidelines or are unaware of them.
In addition, an unusual level of brain cancer was reported between 1951
and 1977, including astrocytoma and glioblastoma, at one manfacturer,
although the manufacturer denies any conclusive linking.
Today, the production of CPVC pipe is strictly regulated. NSF (National
Sanitation Foundation), a public non-profit organization dedicated to public
health and safety, audits many manufacturers of plastic pipe including CPVC,
PVC, acrylonitrile-butadiene-styrene (ABS), polyethylene (PE), and
cross-linked polyethylene (PEX).
Products with the NSF certification are tested in accordance with NSF
Standard 61. PVC and CPVC pipe is tested twice annually for RVCM, ensuring
that production samples remain below established maximum allowable levels.
Products with the NSF-pw certification are further tested for compliance
with all other properties, including health-related.
Therefore, if CPVC is contemplated for use in any structure for a potable
water supply, it is critical that the product is NSF certified. Most codes
make this a requirement, but it is no guarantee that the contractor has
followed these guidelines when purchasing materials. Imported products from
other regions outside the US may not meet these guidelines and could pose a
health risk over time.
Specifying CPVC Pipe (example)
All hot and cold water plumbing pipe shall be manufactured
from a Type IV, Grade I Chlorinated Polyvinyl Chloride (CPVC) compound with
a Cell Classification of 23447-B per ASTM D1784. The pipe shall be
manufactured in strict compliance with ASTM D2846 to SDR 11 Copper Tube Size
(CTS) specifications, consistently meeting or exceeding the quality
assurance requirements of this standard. All CPVC CTS pipe shall be packaged
immediately after its manufacture to prevent damage, and shall be stored
indoors at the manufacturing site until shipped from the factory. The pipe
shall be manufactured in the USA by an ISO 9002 certified manufacturer, and
shall carry the National Sanitation Foundation (NSF) seal of approval for
potable water applications, meeting section NSF 14 and 61 water standards.
Benefits and Considerations of Copper
Benefits of copper pipe include:
Proven, long-term durability in non-acidic installations
Biostatic - does not support bacteria growth
Very diverse material. Can be used for potable water supply,
drain/waste/vent (DWV), natural gas supply, high-pressure steam and other
Very fire resistant; high melt point (1981°F) is 5-times higher than
Widely accepted by all building codes
Contemporary US-Made copper pipe is 99.9% pure according to ASTM
specifications (note that older copper pipe may contain higher amounts of
High rated internal working pressure (see Table)
Ready for use with minimal delay
Can be bent to avoid obstructions, minimizing joints
Available in annealed (soft) and drawn (hard) versions for ultimate
Small external diameter relative to CPVC - fits in tight places
Joints are not bulky
Long warranties available (up to 50 years)
Preferred by most homeowners - can increase resale value of home
Can be pressure tested in 10 minutes
Considerations of copper pipe:
Some report of "metallic taste" to water
Can produce "pin hole" leaks in presence of acidic water
Limited in some areas to use only when water pH is less than 6.5 - 6.8
Can leach lead or copper into water supply
Suitable for use when pH is between 6.5 and 8.5
Subject to jobsite theft
Labor intensive installation process requires skilled plumber
Calcium build-up can occur, constricting water flow
Higher initial installed cost (labor and materials)
Thermal loss - requires insulating jacket
Condensation can occur if not properly insulated
Noisy at high water velocities
Subject to water hammer at velocities higher than 5 FPS; may require
water hammer arrestors to mitigate damage
Copper joints prone to failure at high temperatures (180°F and
Installation with gas torch is a potential fire hazard
Repairs difficult for DIY'ers, requiring special training and tools
Cannot make solder repairs with water in pipes
Price of copper fluctuates over time depending on raw materials demand
Health Effects of Copper Pipe
Although the health side-effects of copper plumbing are
relatively uncommon, the EPA lists copper as a contaminant in drinking
water. The maximum permissible level is 1.3 mg/L. The Plumbing
Manufacturer's Institute is aware of instances of copper-related illnesses.
New copper installations, coupled with aggressive or acidic water can be a
toxic combination. The acid pulls copper molecules into the water supply and
can cause nausea and abdominal discomfort. Furthermore, older copper
installations, including faucets, may contain higher levels of lead,
including lead solder which was commonly used before 1987.
Fine Homebuilding Magazine, "although copper is resistant to corrosion,
there are conditions that copper tubing doesn't like. They include hard well
water; soft, acidic water; excessive water velocity or turbulence in the
line; too much flux during installation; and what the Copper Development
Association calls "aggressive soil conditions." Those who have had trouble
with thinner-walled tubing may switch to type L or type K for longer service
Copper proponents point out that this is not a "pipe" problem, but a
water pH problem and that the source of the aggressive water should be
rectified. However, this is not always practical, particularly with in many
rural areas where wells are common. In severe situations, pH neutralizers
are available which can treat incoming water to provide more benign
conditions to copper pipe.
Acid neutralizers for a single family dwelling are available for less
than $500 and can treat incoming water with pH of 5.5-6.9, depending on
model. Anything under a pH of 7 is considered acidic and should be treated.
Calcite and Corosex are used to raise the pH of the water. Generally, a
whole house sediment filter is recommend to be placed after treatment to
remove unwanted contaminants.
With respect to possible lead poisoning, much has been written about the
harmful effects lead can have, particularly on young children whose brains
are in a state of rapid development. Lead has been linked to learning
disabilities and other side effects which are irreversible. If you suspect
that your drinking water contains lead, have it tested by a certified
laboratory. Testing of so called "first water", which is what comes out of
the tap initially is compared to water which has been flowing for several
minutes. Levels of lead are determined. Often, simply by running water for
20 seconds prior to drinking it is a good safety precaution if your pipes
contain lead solder. Brass fixtures, particularly those made before 1987,
may contain high levels of lead than permitted by current standards.
The Safe Drinking Water Act (SDWA) requires that after June 19, 1986 only
"lead free" pipe, solder or flux may be used in the installation or repair
of (1) Public Water Systems, or (2) any plumbing in residential or
non-residential facility providing water for human consumption, which is
connected to a Public Water System. Under section 1417(d), "lead free" as
defined in the SDWA means that solders and flux may not contain more than
0.2 percent lead, and pipes, pipe fittings, and well pumps may not contain
more than 8.0 percent lead.
Cast fittings are made from Copper Alloy C84400 which consists of 81%
Copper, 7% Lead, 3% Tin and 9% Zinc per ASTM Specification B584. Wrot Copper
fittings are made from commercially pure copper mill products per ASTM
Specifications B75 Allow C12200.
Today, copper pipe made in the US generally conforms to very high levels
of purity with virtually no lead or other minerals. The final product is
called phosphorus-deoxidized, high residual phosphorus copper. It bears the
designation C12200 under the Unified Numbering System (UNS) used to identify
metals and alloys. This copper is 99.9%+ copper (Cu), and is of
essentially the same purity as fire-refined copper produced from ore. It is
produced to the specifications of ASTM B88.
Studies sponsored by the International Copper Association indicate that
copper contains certain beneficial characteristics with respect to bacteria
growth. Copper is biostatic and does not readily support the growth of
bacteria. As a result, copper may offer certain advantages in reduced
formation of biofilms and bacteria growth within the pipe.
Materials Cost Comparison of CPVC to Copper Tubing
As of the time of writing, the following table compares the
US list price of CPVC CTS (copper tubing size) to traditional copper tubing.
Prices will fluctuate but this give a relative indicator of the price
differential between raw materials from two different manufacturers. In
smaller sizes (1/2"-3/4") commonly found in residential applications, CPVC
is 20-30% cheaper. In larger sizes (1"-2"), copper pipe is 10-18% cheaper.
This analysis does not take into account cost of couplings or labor required
to install either product. This table merely highlights that CPVC and copper
are priced competitively with each other. Labor costs would typically swamp
the differential in materials cost between CPVC and copper.
Item (per ft.)
% Price Differential
CPVC vs. Copper
CPVC price list: Thompson Plastics, Inc. as of June
Copper price list: Cambridge-Lee Industries, Inc.
Price Sheet # 42 Effective March , 2001.
Application of Copper Pipe
Domestic Water Service
Solar, Fuel Oil
Domestic Water Service
Solar, Fuel Oil
HVAC, Natural Gas
Domestic Water Service
Solar, Fuel Oil
(L cleaned and capped/degreased)
(K & L cleaned and capped/degreased)
Medical Gas Systems
50 ft. Coils
100 ft. Coils
Source: Cambridge-Lee Industries, Inc.
Working Pressure of Copper Tube
Plumbing Tube Data - Rated Internal Working
Pressure for Copper Tube
Service temperature up to 200º F, S=4800 psi
(annealed), 9000 psi (hard drawn)
Source: Cambridge-Lee Industries, Inc.
Either CPVC or copper plumbing can make a suitable
infrastructure for reliable delivery of potable water. CPVC is best in
situations where aggressive or acidic water is prevalent (pH less than 7)
and there is no acid neutralization scheme in place. CPVC has been in use
for over 35 years and provides reliable service assuming proper installation
is observed. Although most model building codes now approve use of CPVC,
always check with your local building department to ensure its compliance in
your area. Some cities or states have specific restrictions on the use of
CPVC. Copper plumbing is still king when it comes to market share and
consumer preference. To avoid pin hole leaks and copper toxicity, copper
pipe works best in neutral to slightly basic water conditions (pH 7.0 -
8.5). If installed correctly, along with attention to mitigation of water
hammer and erosion due to aggressive water or soil, copper plumbing can last
the life of the structure with little maintenance and overall long-term
Builders Websource® is a corporate
member of ASTM International—a non-profit engineering body dedicated in
part to the standardization of building materials specifications,
products, systems, and test methods for improved health, safety, and
reliability of residential and commercial structures.