The appliance industry is one of the largest consumer product industries. For practical purposes, two categories of appliances are distinguished: ‘Major Home Appliances’ and ‘Comfort Conditioning Appliances’. In 1999, 70.7 million major home appliances and 49.5 million comfort conditioning appliances were sold in the United States, for a total of 120.2 million appliances. The cost of corrosion in home appliances includes the cost of purchasing replacement appliances because of premature failures due to corrosion. For water heaters alone, the replacement cost was estimated at $460 million per year, using a low estimate of 5 percent of the replacement being corrosion-related. The cost of internal corrosion protection for all appliances includes the use of sacrificial anodes ($780 million per year), corrosion resistant materials (no cost estimate), and internal coatings (no cost estimate). The cost of external corrosion protection using coatings was estimated at $260 million per year. Therefore, the estimated total annual direct cost of corrosion in home appliances is at least $1.5 billion.The average consumer buying an appliance is only marginally interested in corrosion issues; therefore, during the useful life of the appliance, no corrosion management is done by consumers.
For example, very few people realize that there is an anode in every water heater, and that this sacrificial bar of metal should be checked and if necessary replaced with a new one, to prevent water heater failure due to internal corrosion. The life expectancy of appliances is determined from past experience and sales data. Improved corrosion design for appliances can increase their life expectancy. However, if improved corrosion protection would mean the use of more expensive components for the appliances, then consumers may not be interested.