Chemical sensitivities differ from allergies, as they do not evoke an immune response, though they can suppress immune function with long-term exposure. There are different types of sensitivities. One of the most common is an aldehyde

Aldehydes are found in perfumes, new furniture, carpets, paints, leathers, and similar items. The nutrients molybdenum and/or selenium can help break down the aldehydes. If you notice a symptom such as a headache, nausea, or fatigue while you paint a room or during/after you get your hair permed; it's most likely an aldehyde sensitivity. Some people have a genetic tendency towards an aldehyde sensitivity, for others it is provoked by a yeast/fungal infection (usually in the digestive tract) where the yeast converts another chemical into the aldehyde, giving you more than you can handle. Whenever painting, installing a new floor or carpet, or new furniture is purchased, it is always a good idea to put certain plants in that room or rooms to help draw the aldehydes out of objects so the aldehydes are removed much more quickly. The plants that help the most with this are golden pathos, spider plant, elephant ear, and lacy tree philodendrons. Use one plant for every 100 or so square feet of room. Or, in the case of some new furniture, putting the plant above or on a table next to it will suffice. Taking the nutrients molybdenum and selenium may help or completely eliminate your aldehyde problem. Always check with a qualified physician first - I have to say that.

Another type of chemical sensitivity is a hydrocarbon sensitivity that is found in more volatile chemicals such as gasoline, as well as products such as Sharpe magic markers. Hydrocarbon sensitivities are usually provoked by a fatigued immune system. Therefore, building up the immune system usually helps a lot.

Many people are also sulfite sensitive, where they cannot handle sulfite containing foods such as wines, certain dried fruits, and most balsamic vinegars. Many restaurants preserve their salad bars with sulfites to keep them [looking] fresh longer. Sulfite sensitivities cause headaches and other nagging symptoms in people and they don't even realize that they are sulfite sensitive. Molybdenum and selenium help this sometimes.

MSG sensitivities are also very common, and there are a lot of people who either don't know their symptoms are coming from MSG, or they don't know that they are getting hidden forms of MSG in their everyday foods. MSG is derived from glutamic acid, a natural amino acid. It is found in foods such as tomatoes, milk, and mushrooms. It functions as a neurotransmitter and combined with the amino acids cysteine and glycine, makes the powerful compound gluthathione, necessary for detoxification and cell repair. The following paragraph on MSG comes from the website http://www.msgmyth.com. I couldn't have explained it better myself. Also check out their Hidden Names for MSG there - they'll surprise you.

"Our normal digestive process slowly breaks down this natural or "bound" glutamic acid and it is then delivered to glutamate receptors in our body and brain. Broken down this way, it is harmless. In a factory, however, the bound glutamic acid in certain foods (corn, molasses, wheat) is broken down or made "free" by various processes (hydrolyzed, autolyzed, modified or fermented with strong chemicals, bacteria, or enzymes) and refined to a white crystal that resembles sugar. This substance is known as monosodium glutamate or MSG. It is 78.2% glutamate, 12.2% sodium, and 9.6% water. It is odorless and has no distinct flavor, although some describe a salty/sweet flavor. Its chemical formulation has been modified and it is technically known as D-glutamic acid. It also contains some L-glutamic acid, pyroglutamic acid, and other contaminants this factory made version causes sensitive individuals more serious reactions than any other form of glutamic acid. Keep in mind that there is no D-glutamic acid, pyroglutamic acid, or other contaminants in the protein found in plants and animals, only L-glutamic acid."