assurance decision will then have to be made on
whether to accept or reject the ingredient or the
concentrate batch.
Alternatives may include utilizing a more
effective anti-oxidant, synergizing it, adding a
chelating agent, or possibly drastically reducing
tramp air (oxygen) in the aerosol can by using a
BOV (bag-on-valve) system, CO2 tunnel, purging
or other approaches. Reformulation using a less
oxidized, or more stable lipid or aldehyde containing
fragrance—or by simply eliminating the
troublesome ingredient—are ultimate options.
Popular cookware lubricant sprays are generally
formulated with about 7% lecithin derivative,
73% vegetable oil and 20% hydrocarbon propellant.
A tiny amount of water may be included in
some. The vegetable is selected from such items
as corn oil, soybean oil, canola oil, sunflower
oil and olive oil, and may contain mixture, mainly for brand extension and
labeling inducements. The vegetable oils are almost always supplied with
traces oil-soluble anti-oxidants to prevent rancidity. These additives are
almost always proprietary and are not identified in label ingredient listings.
If these vegetable oils are stored in sealed drums or in No. 316 stainless
steel tanks with lids, and in cool places, there is little danger of oxidative free radical attack. Some
conservative fillers may opt to blanket their tanks of vegetable oil with heavier-than-air argon gas for
added protection if lengthy storage is anticipated.
Ultimately, there is no need or advantage for fillers to add anti-oxidants when formulating cookware
lubricants. Their main use is in personal care products.
Skin care aerosols usually contain 20 or more ingredients. The concentrates should be compounded
by stirring a minimum of air into the product. Tank transfers should be non-splashing and
made using pumps that do not suck any tramp air into the product. In the packaging program air
(oxygen) minimization is best with BOV systems, and most challenging in the case of pump sprays,
where air enters the dispenser upon every actuation.
Considering all the aspects of anti-oxidant protection, susceptible
personal care aerosols may list ingredients such as one or two antioxidants,
ascorbyl palmitate (Vitamin C Palmitate synergist), EDTA
(chelating agent to sequester trace metal ions) and pH control agents
(to optimize EDTA functionality). The use of two anti-oxidants may be
preferred since they are often synergistic. The usual pH range is very
slightly alkaline: pH = 7.5–8.5 at 25°C.
In Summary
The use of anti-oxidants is generally restricted to personal care specialty
products, especially skin care. This is a very large and expanding
market. They act to prevent oxygen free radicals from creating rancidity
and other malodors due to their chemical action on lipids with double
bonds, aldehydes and other susceptible ingredients used in these
products.
They work be preferentially reacting with oxygen free
radicals to form other free radicals that are too stable to
engage in chain reactions that cause ingredient disruption.
Several anti-oxidants have been described, including
their relative activity, preferred use levels, possible
synergism and other factors.
They are sometimes described as preservatives, which
is actually a much broader term that can include anti-microbial
agents, stabilizers and other ingredients. Spray
June 2019 SPRAY 35