Why not use Neem oil as a natural preservative
Neem oil is a natural product obtained from the seeds and fruits of the evergreen neem tree. It is used in over a hundred pesticide products and has important applications in organic farming and medicine. It has been used as a pesticide for hundreds of years and is considered safe (1).
These days, neem oil is touted as a natural alternative to synthetic preservatives.
Neem oil is a mixture of components, not a pure essential oil. Azadirachtin is the active component responsible for repelling and killing pests. The remaining components include fatty acids, essential oils and other substances. Neem oil components can also be found in other products such as toothpaste, cosmetics, soaps, pet shampoos, supplements, and medications.
Most cosmetic products include water as an ingredient (for emulsification); therefore, preservatives are needed to prevent spoilage and bacterial growth.
If you’ve ever purchased an all-natural, preservative-free cosmetic product, such as a face cream, and detected a “strange smell” before it was completely used up, it means the product has gone bad (i.e. contaminated with yeast, mold, bacteria or fungi). Unfortunately, these products produce natural sugars in a moist environment – the perfect breeding ground (along with a food source) for microbial growth. A product can look and smell good and still be contaminated. If the product is truly all-natural and preservative-free, it should be treated like food: fresh in small batches and refrigerated (and remember, they will expire).
Products made with natural preservatives have a slightly better shelf life if used within 30 days of opening, but you may want to ask: how good are natural preservatives versus synthetic preservatives at controlling and destroying of any intruders to protect your product (and you)? Therefore, although there are effective, naturally derived preservatives, some may be weakened by exposure to air and water and thus may not provide the same broad-spectrum protection as synthetic preservatives.
Neem oil as a natural preservative
When neem oil is used as a preservative, it acts as an antiseptic, antifungal, antibacterial, antiviral, and antiparasitic agent. Sounds pretty good, right? And it’s used as a pesticide, so it must be effective, right? (Although I doubt this argument will work in favor of synthetic preservatives!) Neem oil is effective at keeping oils from going rancid, but it does not protect the product from bacteria and yeast because it is not a broad-spectrum preservative. And it doesn’t seem to like water either. Bad news for technical managers and natural health advocates who want neem oil to be used as a preservative in water-based cosmetics instead of the much more effective (and therefore safer) synthetic preservatives available for this purpose, such as Neolone 950 .Strict regulations require such preservatives to kill all common pathogens. (Look http://personalcaretruth.com/2010/06/why-cosmetics-need-preservatives/ for an excellent article on this subject.)
The half-life of neem oil in water is anywhere between one hour and four days. “Half-life” means that the concentration decreases by 50% in the time frame measured. If we take one day as the half-life of neem oil in water, with a reasonable average of the given limits, we will see a drop in active concentration of 50% in one day, 25% in two days, 12.5% in three days, 6% for four days, 3% for five days, etc. By the time the product reaches the consumer from the day it is manufactured, the neem oil will have completely degraded and be useless as a preservative; therefore, a water-based product containing neem oil as the only preservative is not protected from contamination (which poses a greater risk to your health than synthetic preservatives).
Consumers should be more aware of the occasional misguided advice given by consumer advocacy groups, most notably Safe Cosmetics and the Environmental Working Group (and their database of deep issues). We need to question these groups as critically as we question big industry to start a dialogue. I’m not sure why these groups act like the final authority. Is it because they confirm our fears and suspicions about evil corporations? I don’t know, it’s just a guess. While their intentions may be sound, they often rely heavily on Material Safety Data Sheets (MSDS) – which are generally available to the public – as one of their sources. MSDSs are useful, of course; however, people either forget or don’t know that MSDSs provide safety procedures for workers in industrial environments to follow in the event of massive spills/exposures: these are “worst case scenario” situations that are never implemented for users of these products.
Material Safety Data Sheets (MSDS) are used to help determine product management and occupational safety and health guidelines for workers and emergency personnel who handle or work with the substance in large quantities. They are not intended for consumers, only for those in a professional environment. It’s important to remember when considering the safety issues of the products you use that: “The dose makes the poison,” or, in this case, as preservative expert David Steinberg said, “Remember that preservatives are safer than bacteria ( TM) .”
Back to the neem oil. An organic chemist like myself would look at the chemical structure of azadirachtin, the active ingredient in neem oil, and know that it would not be stable in water, as we discussed earlier, but that it is easily fragmented by this reaction with water on -small, useless pieces. Although most of us are not organic chemists, this is easy enough to understand.
Neem oil is also hydrophobic, meaning that the molecules are repelled by a mass of water. Therefore, in order to mix water and neem oil together (emulsify) for application purposes, certain surfactants must be added. And of course, when you check the pesticide/agricultural literature, you find that the diluted product must be used immediately because of its limited shelf life. But not all neem oil products have this disclaimer. It is important to note that some products containing neem oil remain “stable”. However, the product still loses its neem oil activity; it just continues to deliver pesticidal activity by virtue of the other antimicrobials in the formula.
I don’t think anyone (cosmetic manufacturers, natural product suppliers, green retailers, etc.) is trying to mislead the consumer. More likely it’s a matter of awareness (lack of it). Unfortunately, this type of misinformation puts the health of many customers at risk.
#Neem #oil #natural #preservative