Ads on the radio tout “Orange Oil” as a new "Green" alternative to fumigations and conventional chemical treatments against termites. But is it a valid bio-degradable and ecological alternative or is it just another new marketing ploy? How does it compare to other insecticides and is this a truly effective and reliable termite treatment?

History and Facts: The rind acid of the cistrus is mechanically, steamed or chemically extracted to produce d-Limonene (C10H16 ), a hydrocarbon oil (terpene) also found in conifer and some other plants. The orange oil extract (OOE) is used as fragrance, solvents or dispersing agents found in various products from candles to paint stripper, cleaners, detergents, shampoo, sprays and some insecticides. Orange oil extracts are used mostly as mild repellents against fleas, mites and mosquitoes.

Orange Oil and Termite Treatment: Lab test from UC Berkeley, UC Davis and UC Riverside's Entomology Departments show that d-Limonene has a very short afterlife of only 2 to 3 days and lacks a residual effect to kill and prevent termites from reinfesting treated areas. Orange oil application does not work in soil treatment against Subterranean Termites, even as a repellent due to its short life. When applied directly to wood against Drywood Termites it is critical that the oil reaches each and every termite or the colony will survive and continue feeding on the house. There is no current technology to know if all termites have been killed so most companies also recommend using another termiticide such as Tim-Bor, Bora-Care or Termidor. Comparison results of independant lab controlled tests from the universities listed above show that orange oil is less performant than Termidor or Tim-Bor over long period of time.

Orange Oil vs. Fumigation: According to the Structural Pest Control Board of California “orange oil is another localized treatment tool… against the elusive drywood termite. It is not an alternative to all-encompassing methods of treatment” such as fumigations (SPCB Newsletter). Like Termidor, Bora-Care and Tim-Bor, orange oil treatment entails injection and/or surface treatment of infested wood members. Vikane fumigant (sulfuryl fluoride) has been researched and effectively used for decades with very strict and controlled procedures and specific safety measures, all reviewed and supervised by the California Structural Pest Control Board, the Department of Pesticide Regulations and the Environment Protection Agency. For additional comparison between orange oil and fumigation treatments check: http://www.ywfumigation.com/images/vs.pdf

Orange Oil vs. Other Termiticides: Like plant pyrethrins or synthetic pyrethroids, orange oil is another contact insecticide. The effectivness and smell last only 2 to 3 days and the treatment has no long lasting residual effect against remaining termites or to prevent them from re-infesting treated areas. The challenge is to kill all termites on contact or the colony will survive. This is very hard to do since the technician does not know where all colony members and the queen are located. Orange oil does not have a chemical transfer effect from one termite to another such as Termidor-SC (non-repellent) nor does it have any lasting effect such as as Termidor, Bora-Care or Tim-Bor to keep termites from re-infesting treated areas. Given analysis and results, we prefer and recommend using Termidor, BoraCare or TimBor for a more effective and long lasting treatment.

Orange Oil & Health Hazards: Orange Oil may stain wall coverings and wood surfaces and should be applied carrefully. As a citrus bi-product, orange oil appears as a green alternative. However its health hazard may not be limited to termites. The volatile citrus oil is a repellent to pets and can cause some humans and pets to experience allergies and some breathing difficulties, particularly among asthmatics and citrus allergic subjects with Pantothenic Acid (or Vitamin B-5) deficiency. Though it is labelled low toxicity, 90%+ pure d-limonene is still not approved for retail sale and results from renound organizations such as the IPCS and EPA will soon provide additional data. In doubt, consult your doctor prior to any treatment and inform your pest operator of any allergies you may have to avoid any reactions. An alternative is to use odorless products such as Bora-Care, Tim-Bor or Termidor-SC.

Conclusion: In spite of its "green and eco-friendly" marketing appeal, orange oil is not an all encompassing solution to completely erradicate all termites. Its just another insecticide that may be used in some local treatments. But studies show that orange oil is not as effective or long lasting as TimBor, Boracare or Termidor in eliminating termite colonies, particularly in hidden and hard to reach areas. Depending on accessibility and infestation size, Marin Termite will provide local secondary treatments using orange oil base insecticides, Termidor-SC, Bora-Care and/or Tim-Bor to combat and erradicate Drywood Termites.