ORANGE OIL vs. OTHER TERMITE TREATMENTS

Ads and marketing campaigns from large companies tout orange oil as a “green”, “organic” or “safe” alternative against termites. But is it truly effective against termites or just another marketing ploy? Is orange oil truly a green and organic product that is safer than others? How does it compare to other treatments and is it reliable?

History and Facts: Since the fifties the rind acid of citrus is mechanically, steam or chemically extracted to produce d-Limonene (C10H16), a hydrocarbon oil (terpene) also found in conifer trees and some other plants. Orange oil extract (OOE) is not a comestible product and should not be confused with orange juice. OOE is used as a fragrance, solvent, degreaser and dispersing agent in products like candles, paint stripper, detergents, cleaners, shampoo and sprays. In most insecticides citrus oil has been used as a mild repellent against fleas, mites and ticks. Since the 80s d-Limonene has been added as a fragrance ingredient in mild pest repellents againt ants, mosquitoes, spiders and other common household insects.

Is Orange Oil Organic, Green & Safe?  d-Limonene is extracted from the skin of various citrus fruit (oranges, lemons, grapefruit, etc.) generally used for oils, enhancers and extracts and most likely from non-organic produce due to lower cost. Unless it is made exclusively from organic produce, orange oil would not qualify for the “Organic” label we expect on our local fruit stands. As a rind bi-product, d-Limonene would seem like a green and safe product. However orange oil is highly acidic and can cause skin and eye irriation and damage, it is flammable and should be use cautiously, and its vapors can cause respiratory problems. The MSDS for d-Limonene requires use of protective gear including goggles and oil compatible nitril gloves, clothing and a breathing mask suited for oil fumes to prevent skin, eye and respiratory injury. Orange oil is a powerful acidic product that should not be used on plastics, painted or laquered surfaces including hardwood floors, painted trim and baseboards, vinyl surfaces, wallpapers and cloth wall or floor coverings to prevent damage. It is not advised to use orange oil on crops unless diluted as the acidity of d-Limonene may damage plants.

 

Orange Oil and Termites – Separating Facts From Fiction: In early 2000 d-Limonene was once again revived and heavily marketed with the backing of Florida University researchers and big financial investors under a new exclusive name. Ads showing children drinking orange juice suggest that orange oil is as natural and safe as eating oranges. But orange juice is not to be confused with orange oil, which is acidic and a strong skin and eye irritant against pets and humans. These ads try to attract as many customers as possible and do not mention that orange oil is not effective against all types of termites and that the best results from research show limited effectiveness against drywood termites, the target pest of orange oil treatments.

Orange Oil and Termite Treatments: Lab test and results from UC Berkeley, Davis and Riverside's Entomology Departments show that d-Limonene has a short life of only a few days after application. It lacks the required residual effect to effectively kill and prevent whole drywood termite colonies from surviving the treatment and re-infesting the treated wood members. Unlike other chemical treatment against Drywood Termites, it is critical that orange oil reaches each and every termite in the colony or the colony may survive. Unfortunately no current technology can tell if all termites have been killed at time of treatment, so most companies treating with orange oil also recommend using another residual termiticide such as Tim-Bor, Bora-Care or Termidor to leave a long term residual effect that orange oil does not provide.

Local Treatment	Percent Death After 3 Months	Smell/Odor Sent/Vapor	Type of Insecticide	Transfer Effect Between Termites	Residual Effect After Treatment
Termidor-SC (Fipronil)	100%	None	Non-Repellent	Yes	Yes
BoraCare/TimBor (Sodium Borate)	98-99%	None	Non-Repellent	No	Yes
Optigard-ZT (Thiametoxam)	81%	Yes	Non-Repellent	Yes	Yes
XT-2000 (d-Limonene)	81%	Yes	Contact/Repellent	No	No
Premise 75 (Imidacloprid)	41%	None	Non-Repellent	Yes	Yes
Untreated	3%	N/A	N/A	No	N/A

SOURCE: Dr. Vernard Lewis, UC Berkeley & Dr. Michael Rust, UC Riverside – 2009

Orange Oil vs. Fumigation:  After some companies claimed that orange oil treatments were similar or better than fumigation treatments, the California Structural Pest Control Board reminded pest management professionals not to confuse and misinform customers: “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. Like Termidor, BoraCare and Tim-Bor, orange oil treatment entails injection or surface treatment of wood members. Sulfuryl fluoride fumigation is best for complete eradication of large infestations or to inaccessible areas where a local treatment is not feasible. Fumigation has been extensively researched and effectively used for decades with strict procedures and specific control safety measures reviewed and supervised by Structural Pest Control Board, EPA and Department of Pesticide Regulation. Every year, thousands of residential and commercial structures, freight railroad cars and trucks, food silo and storage depots are fumigated under strict supervision against termites, beetles, rodents and other food born pests. Fumigation is always considered a last result option and may be the only solution for large and widespread infestations where local treatments are not technically or financial feasible.We will discuss the pros and cons, advantages and inconveniences or fumigation in our next blog.

 

Orange Oil vs. Other Termiticides: Like other plant pyrethrums or pyrethroids, orange oil is a contact insecticide. The effectiveness and smell last only a few days and has no residual effect to kill or prevent termite re-infestation like TimBor. Orange oil does not have a transfer effect between termites like Termidor-SC or Altriset (non-repellent), and the scent of orange oil can be detected by termites who will avoid it. Given analysis and results, we recommend treatment with Termidor, BoraCare or TimBor for a more effective and lasting treatment, even when using orange oil as an insecticide.

Orange Oil & Health Hazards: Orange Oil can stain wall coverings and hardwood flooring and should be applied carefully. The volatile citrus oil is a repellent to many pets and can cause some humans and pets to experience allergies and breathing difficulties to asthmatics and citrus allergic subjects with Pantothenic Acid (or Vitamin B-5) deficiency. Though it is the product of citrus peels that may seems less toxic, 92% d-Limonene (orange oil) is a very acidic product that can cause severe skin and eye damage and it is still not approved as a retail pesticide, even after more than 10 years of research from the IPCS and EPA. Chemical treatments with orange oil require protective gear to prevent injury and should not be used without precaution. Diluted orange oil types of pesticides for gardening are available as mild repellents. In doubt, consult your doctor before treatment, tell your pest operator of allergies you may have to avoid reactions, always follow the label direction and always wear protective gear.

Conclusion: In spite of its ”green and eco-friendly" marketing appeal, orange oil is not as effective or long lasting against drywood termites as other termiticides like TimBor, BoraCare and Termidor-SC. Depending on the accessibility and size of the infestation, we apply local treatments using one or several reliable termiticides to combat and eradicate Drywood Termite infestations. 

For more information from one of our Licensed Inspectors or to have your home inspected call us at (415) 456-9620