Let me introduce you to guayule (pronounced why-you-lee). Guayule is a desert shrub from the southwest United States that seems to be proving itself as an acceptable alternative to the allergenic rubber latex currently used in the U.S. The allergenic latex comes from the Brazilian rubber tree (Hevea brasiliensis), which is grown primarily in Malaysia. Currently, the U.S. relies completely on foreign imports of the Hevea latex for use in rubber manufacturing. More than 2,000 different species of plants can produce rubber, but guayule and Hevea are the only two that have had commercial success.
Guayule has an interesting history. It was first used for rubber production in the early 1900s but fell into disuse because of civil unrest in Mexico, as well as depletion of the plant. A company in California started production again in the 1920’s, but the effort ceased again, this time because of the Great Depression. During World War II, the U.S. government started the Emergency Rubber Project to meet the need for the transportation and defense industries, since Japan had cut off the main supply of rubber from Southeast Asia. Guayule rubber was produced in huge quantities. However, at the end of the war, Winston Churchill asked President Truman to cease guayule production, in order to protect the interests of the existing British rubber plantations in Malaysia. Truman agreed the remaining guayule plants were destroyed, and the production information was “classified” by the U.S. government until the 1970s. In the 1970s, high oil prices and the increased cost of synthetic rubber caused renewed interest in guayule. Scientific research and political lobbying improved guayule’s commercial viability as an alternative source of rubber.
Enter the 1990s and the explosion of latex allergy. The United States Department of Agriculture and a company named Yulex teamed up in 1997 to explore methods of guayule latex production. Preliminary research trials have shown guayule to be an effective barrier against bacteria and viruses. Prototype gloves and condoms are impermeable to viruses smaller than bacteria, and to those the same size or smaller than disease-causing viruses such as HIV, hepatitis B, and herpes simplex. The other good news is that guayule has not caused allergic reactions in human trials, including in people with a pre-existing Type I latex allergy.
Yulex currently holds two patents that cover the process for extracting latex from the guayule shrub, as well as the end products derived from guayule latex extraction. The company has already established relationships with manufacturers of medical products and is focusing first on gloves, condoms, and catheters. Yulex plans to launch a line of surgical gloves by 2017, followed by the marketing of catheters and condoms. A few specialty products such as surgical tubing, dental dams, and medical adhesives may be available by late 2018. Guayule latex has the potential to be used in over 300 different medical items.