There are between 50 and 75 countertop manufacturers in the southern California four county area that includes Los Angeles, Orange, Riverside and San Bernardino. There may be as many as 400 cabinet manufacturers and 1,000 woodworking manufacturers in the same four county area. Most of these companies are small and medium sized businesses. Many of the countertop, cabinet and woodworking companies manufacture countertops. The companies use adhesives to bond veneer to wood, particleboard and medium density fiberboard. Many manufacturers have post-forming operations where the edges of the countertops are bonded using adhesives. Several years ago, adhesive formulators used 1,1,1-trichloroethane (TCA) in the adhesives they offered to this industry. TCA production was banned in 1996 because TCA contributes to stratospheric ozone depletion. In the mid to late 1990s, the formulators stopped using TCA and they began formulating with alternatives like methylene chloride (METH) and various types of non-chlorinated solvents including toluene, xylene, methyl ethyl ketone (MEK), hexane and heptane. Companies that manufactured countertops converted to adhesives that relied on METH or the other VOC solvents. They also used many of these same solvents to clean their application equipment.