Answer: Many solvent-based adhesives have been replaced by emulsions and 100% reactive systems because of health and flammability concerns, plus legislation covering VOCs. However, there are still some adhesives that use solvents for performance and other reasons. Many pressure-sensitive adhesives are still made using solvents for performance and productivity reasons, although only the manufacturer has to handle the solvents (the end-user, of course, is not exposed to them). Some rubber adhesives, such as Neoprene-based products, often work better in their solvent forms than in latex. Solvent cements are still widely used in medical device manufacturing to bond PVC tubing and are considered essential in bonding plastic piping for plumbing applications. There has been some renewed interest in using solvents that are derived from renewable "biobased" feedstocks rather than from petroleum resources. Most people are aware of solvents like d-limonene, which is extracted from citrus fruits. Recently, new cost-efficient processes have been devised to generate solvents like 2-methyl tetrahydrofuran. The main commercial goal for this solvent is to make P-Series fuels that are formulated for flexible fuel vehicles, but the solvent shows potential as a lower-cost alternative to solvents like THF that are used to formulate PVC pipe cements.