Taps and Faucets
High quality taps and faucets are often made from chromium-nickel plated brass. These fixtures are bright, durable and have easy-to-clean surfaces. Such products can be expected to give many years, often decades, of excellent performance. Moreover, when it comes time to replace them, they are almost always collected and recycled back into new alloy products.
There is one possible concern, however: if water is left standing in such taps and faucets for an extended period, it is possible for nickel in that water to become elevated above normal levels. Consumption of this water can be avoided by running the tap for several seconds before collecting water for use. (Running the tap briefly to flush such standing water has long been a recommended practice for reasons other than the possible presence of nickel.)
How does the nickel get there?
The exterior of the brass tap or faucet is plated with a layer of nickel, which is then plated with a thin finishing layer of chromium. During the plating process, it’s possible that nickel could be plated on some of the interior surfaces of the fixture. Because the plating characteristics of chromium differ from those of nickel, it’s also possible that the chromium will not cover completely the nickel layer that may be inside the fixture.
The amount of nickel dissolved in such water, while very small, may be elevated relative to the amount of nickel normally present in the water. How elevated will depend on a variety of factors including the area of exposed nickel, the softness or hardness of the water, the length of time the water has been standing, and the age of the taps and faucets. The higher levels of nickel will be found when soft water has stagnated in new fixtures.
The actual quantity of standing water and the area of nickel exposed, if any, will be limited by the design and size of the fixture, and in any event, will be small. For example, a typical combined (hot and cold) faucet fixture will hold less than 250 ml of water (approximately 1 cup) and a single tap much less.
What is the significance of the presence of nickel in water?
While elevated dissolved nickel has been observed in water from chromium-nickel plated taps, we are not
aware of any reports in the scientific literature of adverse health consequences. However, there is a very
small subgroup of nickel sensitized people who might experience flare-ups of nickel dermatitis after
ingesting high levels of nickel in foodstuffs and water. (More information on nickel allergic contact dermatitis). In addition, laboratory
studies on pregnant female rats dosed with levels of soluble nickel approximately 400 times higher (per kilo
of body weight) than normal total human intakes from food, water and other sources have shown negative
impacts on the number of live births per rat litter. We are not aware of any reports in the scientific
literature of comparable exposures or effects for individuals in domestic environments.
What can I do to reduce my intake of nickel?
If there is any elevated level of nickel in water, it will be found in the first water out of the tap after a
stagnant period. This is called "first draw" water. The recommended practice is to let that first water pass
before collecting water for drinking or cooking. This common practice of flushing the fixture will work just
as well for other metals from the fixture, e.g., lead, and is particularly relevant if a fixture has not been
used for a period of time – overnight or longer – or if it is newly installed.
