|Molar mass||172.26 g·mol−1|
Except where noted otherwise, data is given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
|what is: / ?)(|
p-Menthane-3,8-diol, also known as para-menthane-3,8-diol, PMD, or menthoglycol, is an active ingredient used in insect repellents. It smells similar to menthol and has a cooling feel. There are eight possible isomers of PMD, and the exact composition is rarely specified and is commonly assumed to be a complex mixture.
E. citriodora oil, when refined to increase its PMD content for use in insect repellents, is known in the United States as oil of lemon eucalyptus (OLE) or by the tradename Citriodiol. Some commercial PMD products are not made from E. citriodora oil, but rather from synthetic citronellal.
Refined OLE contains approximately 64% PMD (a mixture of the cis and trans isomers of p-menthane-3,8-diol). OLE has been notified under the European Biocidal Products Directive (BPD) 98/8/EC (now BPR Regulation (EU) No. 528/212) under its generic name "PMD rich botanic oil" and is currently proceeding through the registration process with the Health and Safety Executive in the UK. It is also registered with Canada's Pest Management Regulatory Agency under the generic name "PMD and related oil of lemon eucalyptus compounds". It is the only natural active ingredient that is permitted to be used an insect repellent in the United States and Europe.
PMD can be synthetically manufactured from materials derived from natural sources. This 2011 study also shows that E. citriodora oil contains only 1-2% PMD and is therefore different from OLE as registered with the EPA which has a minimum 64% PMD. A 2006 study showed that PMD is as effective as DEET when used in like quantities.
- John C. Leffingwell. "Cool without menthol & cooler than menthol and cooling compounds as insect repellents". Leffingwell & Associates.
- PubChem Compound Search
- Drapeau, Jeremy (2011). "Green synthesis of para-Menthane-3,8-diol from Eucalyptus citriodora: Application for repellent products". Comptes Rendus Chimie 14 (7-8): 629–635. doi:10.1016/j.crci.2011.02.008.
- Carroll, Scott P.; Loye, Jenella (2006). "PMD, a Registered Botanical Mosquito Repellent with Deet-Like Efficacy". Journal of the American Mosquito Control Association 22 (3): 507–13. doi:10.2987/8756-971X(2006)22[507:PARBMR]2.0.CO;2. PMID 17067054.