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What is Chemical Sensitivities?

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Three Things You Should Know

Before I go into detail about Chemical Sensitivities, it is important to note that most chemicals and fragrances are potentially harmful to anyone, not just a person with CS. Unfortunately, modern society has chosen to use many dangerous chemicals and synthetic substances that our bodies do not have the innate ability to detoxify. There is a great deal of research into the potential long term effects of our continuous exposure to chemicals and fragrances, much of which points to a possible correlation with the increased prevalence of cancer and other terminal illnesses, asthma and other respiratory diseases, cognitive issues and learning disabilities/developmental delay (including autism), mental health and behavioral problems, and many other illnesses. Many of the chemicals and fragrances in our everyday products are neurotoxins (damage the nervous system and brain), endocrine disruptors (disrupt the normal functioning of hormones), carcinogens (contribute to the development of cancerous cells), hepatotoxins (damage the liver), mutagens (alter the DNA in cells), allergens (cause allergic reactions), reproductive chemicals (affect fertility), and teratogens/embryotoxins (interfere with the normal development of an embryo or fetus). For more information and links to various research, please read the Causes section below as well as Why Is Fragrance-Free/Non-Toxic Living So Important: Health Risks for All Individuals.


Chemical Sensitivities (CS) - also known as Multiple Chemical Sensitivity (MCS), Environmental Illness, or Chemical Injury - is a chronic condition in which a person develops various adverse symptoms from exposure to chemicals in their environment. Although healthy people often react to toxic substances, the difference is that a person with CS has much more severe, debilitating, and prolonged symptoms and also reacts to much smaller amounts of chemicals. Their reactions are repetitive and reproducible, and symptoms are generally relieved after the toxic chemicals are removed or within a consistent amount of time thereafter. Chemical Sensitivities affects approximately 12 - 30% of the population, depending on the source consulted. (Sources: 1, 2, 3)


What do we mean by “chemicals?” Obviously, everything around us is made of certain chemicals, including our bodies, the trees in our backyard, and the stars in the sky. Not all chemicals are harmful. In general, what I am referring to on this website are those chemicals that are synthetic or man-made. However, this distinction is not always clear as many naturally occurring substances can be toxic to the body as well, including lead, mercury, aluminum, arsenic, and radon.

Fragrance chemicals, specifically, tend to cause some of the greatest difficulty for a chemically sensitive person. When the word “fragrance” is listed in the ingredients of a product, it is a generic term that can represent literally hundreds of chemicals and chemical combinations. Fragrance chemicals are designed to stick to people’s skin and clothes, and also to waft long distances through the air – that is why they create such problems for the chemically sensitive person. Some synthetic chemicals are only a health risk to the person using them. But many are a health risk to everyone around that person as well. An example of this is fragrance chemicals - you cannot use them without negatively affecting the health of everyone around you.

It is also important to note that a chemical does NOT have to have a strong smell in order to be toxic. In fact, many dangerous chemicals are completely odorless. (Yes, the name of this website is a bit of a misnomer!)

The following is a list of many of the specific products and chemicals that can cause a chemically sensitive person to have a reaction.

- Perfumes and colognes
- Fragranced laundry detergent (on their clothes or somebody else's)
- Fabric softener and dryer sheets (even if fragrance-free, these still contain chemicals that
   are carcinogens, narcotics, neurotoxics, and "hazardous waste" as classified by the EPA)
- Fragranced hand and body lotions, soap, and shampoo
- Most commercial air fresheners (including Febreeze, which contains over 80 KNOWN toxic
- Cigarette smoke and smoke from woodstoves, campfires, burning leaves, etc.
- New carpeting, furniture, or flooring, and other household furnishings and fixtures
  (all contain a multitude of chemicals that “off-gas” into the air)
- Toxic household mold and mildew
- Ink, toner, magazines, newspapers, and other printed materials
- Petrochemical fuels, including diesel, gasoline, and kerosene
- Cleaning products made with harsh detergents, solvents, or fragrances
- Pesticides and herbicides (both in food and in the air)
- Paints, glues, and sealants
- New clothing and fabrics (these are processed with
many chemicals, including
- New electronics or appliances (both internal and external parts off-gas very strong
- Chlorinated water in swimming pools 
- Fluoride, chlorine, and other chemicals found in drinking water
- Excessive quantities of dust and dust mites
- Artificial colors, flavors, sweeteners, and preservatives in food
- Residues of chemicals and fragrances on someone's clothing or hair
- Cats, dogs, and other animals

Also be sure to check out the American Academy of Environmental Medicine's definition of Chemical Sensitivities.


The chemicals in our environment and everyday personal care products affect multiple organs and bodily systems, including the immune, central nervous, respiratory, endocrine, digestive, musculoskeletal, and reproductive systems. Thus, the symptoms of Chemical Sensitivities vary greatly amongst different individuals. The most common symptoms include: headaches, migraines, or sinus issues; extreme fatigue, weakness, and loss of energy; cognitive dysfunction such as difficulty concentrating, memory loss, and  severe disorientation, commonly referred to as “brain fog”; dizziness, vertigo, and  heart palpitations or arrhythmia; nausea and vomiting; itching, burning, rashes, hives, and other skin irritation; difficulty breathing, coughing, congestion, and sore throat; muscle and joint pain; and many other symptoms. In severe cases, one can even experience seizures, loss of consciousness, or anaphylactic shock (an extreme allergic reaction that can involve heart failure, circulatory collapse, and/or severe asthma-like breathing difficulty). These symptoms are often triggered from exposure to minute amounts of chemicals, such as a friend who is wearing perfume or whose clothes were laundered in fragranced detergent and dryer sheets.

Although many people, including healthy people, may have small reactions to certain chemicals, such as getting a headache after sitting next to someone wearing perfume, the experience is very different for a person with CS. For most chemically sensitive people, these symptoms are very severe, persistent, and debilitating. They may have chronic brutal headaches that last day in and day out for months or longer. They may be so tired  and weak that they literally cannot get out of bed - lifting their arms and legs feels like an astronomical effort and they literally cannot do it. Or the cognitive symptoms may become so severe that they cannot organize or understand their own thinking - they have difficulty following a train of thought to its completion, they struggle to carry on a normal conversation, they are disoriented and lose brief moments of consciousness, and cannot drive safely. Difficulty breathing may lead to anaphylactic shock, and many other symptoms can also become very extreme and debilitating.

For more information on the daily experience of people living with Chemical Sensitivities, please see What's It Like to Live With Chemical Sensitivities?


As mentioned above, chemicals and fragrances are harmful to all people, whether that harm is noticeable or not. Why someone would develop a noticeable sensitivity to chemicals and fragrances is the subject of this section.

Chemical Sensitivities can occur on its own or it can be a symptom  of  another illness which has weakened the body, its immune system, and its detoxification pathways. Chronic infections are a huge factor in the development of CS - they are much more common than most people think and are generally undiagnosed. These include chronic viruses (i.e. Epstein Barr, Cytomegalovirus, Parvovirus), chronic bacterial infections (i.e. Lyme Disease and its coinfections, Streptococcus, Staphylococcus), parasites (yes, surprisingly common), yeast overgrowth (Candida), fungal infections, and gut dysbiosis in any form. Biotoxin illness from infections or from mold exposure is also a huge factor which requires very specific treatment (see for details).

Other illnesses than can cause a sensitivity to chemicals  or fragrances include Asthma, AIDS, Cancer, Chronic Fatigue Syndrome, Fibromyalgia, Addison's Disease (or secondary adrenal issues), Mast Cell Activation Syndrome, sinus problems, autoimmune disorders, heavy metal toxicity, unidentified allergies, leaky gut syndrome, etc. The reverse is also true - the chemicals in our environment can contribute to the development of many of the above diseases as well - either directly (by causing direct damage to the affected bodily systems) or indirectly (by weakening the body's defenses and making a person more susceptible to illness).
Various inherited genetic defects can also be a cause of CS - a mutation of the MTHFR gene, for example, can severely inhibit the body's detoxification abilities.

There is a lot of debate regarding the cause of Chemical Sensitivities when not caused by another illness. This is largely due to the lack of attention given to this condition by doctors and medical research organizations. However, the general consensus is that CS is commonly caused by one high-dose exposure to a certain chemical or combination of chemicals, or by chronic and repeated exposure to any amount of a chemical or combination of chemicals. In our society, chemical exposure is impossible to avoid; therefore, we are all at risk for developing CS and should engage in regular detoxification efforts and play close attention to our environment, our diet, the products, we use, etc.

There are a couple of different theories as to why chemical exposures would lead to the development of CS.

With the “total load” theory, the idea is that t
he body has a relatively finite space to work with and the detoxification pathways, specifically, have a certain capacity of how much toxic material they can remove and how quickly. Since we are exposed to and absorb such an overwhelming amount of toxins, the body cannot effectively remove it all and trace amounts are left behind. Even a healthy person cannot effectively process and remove everything. The toxic material left behind builds up and is stored in fatty tissues and other areas of the body. The more build up there is, the less efficient the body becomes at detoxing from new exposures. Eventually a tipping point is reached and the body is so severely hampered in its detoxification process that symptoms or illness develop. Just our daily exposure to everyday toxins can be enough to actually cause Chemical Sensitivities - our bodies simply can't keep up with the modern chemical load.

Another theory is that the chemicals we are exposed to in our everyday environment cause direct damage to the body, resulting in weakened functioning of various organs, systems, and processes. On a daily basis, we are exposed to potent chemicals that can cause significant damage to the immune, digestive, endocrine, nervous, respiratory and other systems. The resulting imbalances in the body can weaken many essential physiological processes, including the detoxification process,  and lead to a sensitivity to chemicals and fragrance. This is made worse by the fact that most people don't get the nutrients they need to support these essential processes due to soil depletion and poor dietary choices. Thus, the cycle continues and the damage to the body increases.

Yet another theory focuses on the injury done to the brain specifically. This theory proposes that severe or prolonged chemical exposures can injure an individual’s brain on a neurological level, particularly in the area of the limbic system, and that this injury is what leads to the development of Chemical Sensitivities. The result is that the limbic system gets locked into an overactive condition in response to external threats and creates a continual state of emergency within the body. The brain literally becomes wired to look for and perceive threats. The brain then triggers the shutting down or vamping up of certain
bodily systems and processes as an effort at self-preservation, and thus creates a chronic stress response in the body. This theory has become more and more prevalent within the CS community over the past several years, and many people are having huge success in treating their CS using brain retraining programs. For more information, visit

The most commonly reported exposures that trigger the onset of CS are indoor air pollution. This can include a variety of specific exposures, including moving into a new home with brand new paints, stains, sealants, carpeting, pressure-treated wood, and other new materials or furnishings; working in a new or recently renovated building; having toxic mold and mildew in your home or workplace, or other contaminants such as radon, asbestos, carbon monoxide, lead-based paint, or poorly contained heating fuels; or working in a profession where you are regularly exposed to  toxins, such as construction, agriculture, transportation, automotive repair, cosmetology, etc. (Office work can also be a toxic profession if you sit close to a printer or photocopier.) In some of these situations, especially the case of toxic mold, a person is often given the diagnosis of Sick Building Syndrome, a condition whose symptoms are generally identical to Chemical Sensitivities. Once the contaminants are removed, it is likely that the person's health will improve, but sometimes the damage is so severe that it can take years or even decades to reverse; in some cases, it may be permanent.

Occupational exposure is also a commonly reported trigger of the onset of CS. Many professions involve use of or contact with particular chemicals, including construction and manufacturing, hospital and other medical work, landscaping and lawn care, cosmetology and beauty salons, printing and general office work, mining, and many more.

Outdoor air pollution, especially when living in a large city or a heavily polluted area, can also be a significant load on the body, as can the many daily exposures that we don’t even think about such as second hand smoke, residential pesticide or herbicide use, and pesticide residue in our foods. Local spraying of pesticides is also a common trigger of CS.

It is important to note that Chemical Sensitivities is not about a person simply disliking smells or fragrances. It is about the chemical composition of these smells; natural scents are generally not a problem for people with CS. It also is not a psychological reaction. It is a real, physiological reaction to chemicals in the environment, and these reactions often occur without the person's awareness of the presence of these chemicals.


It can be difficult to recover from Chemical Sensitivities, but it can be done if you are dedicated and patient. Possibly the most difficult part of it is determining what you have to do to get better.  There has not been enough solid medical research conducted about CS and many, if not most, doctors do not know how to treat it. People with CS often end up going from doctor to doctor trying to find a solution and spending lots of money trying a multitude of supplements, treatments, or medications that are recommended to them. They often end up conducting their own research and, in effect, becoming their own doctor. Unfortunately, many chemically sensitive people become sicker as time goes on and do not improve. But it is possible to get better or at least to dramatically decrease the level of sensitivity. In my experience, and from what I understand about others' experiences, recovery is much more successful when using a holistic approach and working with a combination of traditional medical doctors (such as a primary care physician, allergist, immunologist, nutritionist, or other specialist) and alternative practitioners (such as a naturopath, homeopath, chiropractor, acupuncturist, or energy healer). If you are willing to look into multiple approaches and to explore both physical and mental/emotional healing, you will most likely get better results.

The two most common methods of treatment for Chemical Sensitivities are avoidance and detoxification. Avoidance means literally staying away from all fragrances and other toxic chemicals as much as possible. Although this will help a person's health a lot, it is virtually impossible unless the person wishes to have no home, no car, no job, no bed, no clothes, no books, no computer, and definitely no social life. (For more on this topic, please see Can You Avoid Chemicals?.) It is very important to eliminate as many toxic exposures as you can, just remember this is not the cure. Some of the heaviest toxins that people are regularly exposed to include: household mold and mildew, chemically based building materials (fresh paint, floor varnish, pressure-treated wood, etc.), household carpets (especially if new),  perfume/cologne, scented laundry detergent, dryer sheets, fabric softener,  air fresheners, and cigarette or wood stove smoke. It is important for EVERYONE to avoid these things as much as possible. Without eliminating these, healing will be slow or non-existent. (For more on this topic, please see How to Go Fragrance-Free/Non-Toxic.)

The next step is to treat any underlying conditions which contribute to the Chemical Sensitivities. In many cases, CS will not improve without treating these underlying conditions.  See the full list in the Causes section above. The two most common underlying conditions, in my experience are:

  1. Chronic infections - These are much more common than you would think! And are usually undiagnosed. These include chronic viruses (i.e. Epstein Barr, Cytomegalovirus, Parvovirus), chronic bacterial infections (i.e. Lyme Disease and its coinfections, Streptococcus, Staphylococcus), parasites (yes, surprisingly common), yeast overgrowth (Candida), fungal infections, and gut dysbiosis in any form. Biotoxin illness from infections or from mold exposure is also a huge factor which requires very specific treatment (see for details). For many with CS the more they treat the underlying infections, the healthier they get.

  2. Genetic defects that interfere with your body's detox pathways. Surprisingly, a huge portion of the population has these defects. If even one portion of your detox pathways is not functioning correctly, your body will not detox well on its own and using a sauna or doing a cleanse won't be very effective. It's common to feel worse while detoxing, but if you feel awful even after detoxing consistently for years, then there is probably a genetic defect at play. These defects can't be "fixed" per se, but they can be circumvented with supplements and nutrition. You can do your own genetic testing through and then work with a Naturopath (or a doctor that incorporates natural medicine) with a good understanding of genetic issues, specifically related to detox pathways.

A good example of underlying conditions is Lyme Disease. The Lyme bacteria is constantly releasing neurotoxins into the body and overloading the body's detox pathways. If your detox pathways are already compromised by a genetic issue as mentioned above, this will make things even worse. Lyme also interferes with the optimal functioning of  many (if not all) bodily systems. Without killing off the Lyme bacteria (which will take a concerted effort and multiple types of treatment), the body will remain in toxic overload and be unable to heal from CS.

If you believe that your CS may be caused by or exacerbated by another condition or weakness in the body, work with a practitioner who can identify these weaknesses and help bring you back into balance. In my experience, Naturopaths have the best comprehensive understanding of all the different components involved in this type of healing, however other types of doctors can certainly help as well.

The next step is to work to detoxify the body as much is possible. This decreases the total load of chemicals that one carries around on a daily basis, and can help many people with CS to become less reactive. Detoxification is a much more complex process than is commonly understood. It is very important to work with a doctor or health care practitioner who fully understands this. Common methods of detoxing include chelation; saunas; dietary changes; colon, liver, or digestive system cleanses; specific vitamins, minerals, and antioxidants (i.e. the correct form of B12 for your particular genetic makeup, or certain precursors to glutathione, which is your body's master antioxidant and detoxifier); specific herbs, high quality essential oils, and other natural supplements (i.e. lemon oil, milk thistle, dandelion root, bentonite clay, and a good quality probiotic); removal of mercury amalgams; and many alternative medicine treatments such as acupuncture, homeopathy, energy work, and ionizing foot baths. Most people find that a combination of body detoxification and avoidance of chemicals and fragrances works best. Drinking lots of water is also important, as is replenishing essential nutrients lost during chronic illness and extensive detoxification.

Another option is to work with a brain retraining program such as Annie Hopper's Dynamic Neural Retraining System or the Gupta Amygdala Retraining Program. Check out for more information or search online using the term "neuroplasticity MCS." These programs have become increasingly popular within the past several years, and many people are having huge improvements in their health. Some people are having success using only these programs, and some are having success using these programs in combination with other methods of treatment as mentioned above.

Lastly, and I cannot stress this enough, it is crucial to look at your diet. First of all, look for underlying food allergies or sensitivities by working with a trusted doctor and/or trying various elimination diets to determine problem foods. But most importantly, pay attention to the overall nutritional quality of what you are eating. If you are not getting enough nutrients, if you are overeating, or if you are consuming a lot of foods with artificial colors, flavors, sweeteners, or preservatives or a lot of processed, starchy, high-carb, or sugary foods, this may be worsening your Chemical Sensitivities (as well as many of the underlying conditions that contribute to CS, such as yeast/fungal overgrowth, leaky gut syndrome, etc.). Also consider eliminating foods that are often contaminated with fungus, mold, and mold mycotoxins during their processing. These include: alcohol, wheat/gluten, sugar, corn, rye, barley, peanuts, cottonseed oil, sorghum, hard cheeses, and chocolate. Be sure to drink lots of clean water as well. Talk with your doctor or a nutritionist about your dietary needs and do some of your own research about the correlation with CS. You  may also wish to consult a practitioner who presents more unique dietary guidelines, such as those practicing Chinese medicine or Ayurvedic (Indian) medicine.  Just like any other form of treatment, if you are willing to try new things and to go through a process of trial and error with your food, you will eventually find what does and doesn't work for you and your body.

 Three Important Things You Should Know

I do not wish to go into an extensive description of the causes and physiological processes of Chemical Sensitivities here. I have presented a brief summary that should give you an idea of the overall problem, and if you want more details there are plenty of websites and other resources where this information can be found. What deserves the most attention here, in my opinion, are the following three points.

1) Chemical Sensitivities is real. People with Chemical Sensitivities are reacting to real chemicals in the environment. You may not smell anything or feel any ill effects yourself. You may think the person with CS is exaggerating, faking, or worrying so much that they are making themselves sick. However, they are, in fact, reacting to real chemicals in the environment. Because of their condition, they are so sensitive that even very low levels of toxic chemicals can trigger symptoms.

2) Chemical Sensitivities is debilitating and disabling. There are an astonishing number of people who are chronically disabled from this condition and cannot work, play, live, or love without getting incredibly sick. As mentioned earlier, many people with CS do not get better despite continually seeking many forms of treatment. The progression of this illness can be quick and drastic, and their lives become smaller and smaller as their limitations increase. Soon, many people with Chemical Sensitivities are living almost completely isolated from society because it is the only way that they can effectively manage their symptoms. And for those that do get better, it can take a lot of time and a lot of effort. (For more information, please see What’s It Like To Live With Chemical Sensitivities?)

3) Chemical Sensitivities is a social disease. It has been created by a society that continually chooses to manufacture its products and conduct its industries using incredibly hazardous chemicals. It is becoming more prevalent as more and more chemicals are used. And since we created it, we can put an end to it. Possibly more than any other illness, you have the power to help people with Chemical Sensitivities. Their lives are in your hands. Every person who stops using fragranced products is making a difference. Every organization that stops polluting the air we breathe or makes an effort to detoxify their workplace is making a difference. This is what it is going to take. One by one, people have to start caring enough to make changes in their lives. For many individuals, these changes require very little effort yet are incredibly large in effect. (For more discussion on this topic, please see Why Is Fragrance-Free/Non-Toxic Living So Important? and How To Go Fragrance-Free/Non-Toxic.)


My goal with this website is to educate people about the daily experiences of people living with CS and how imperative it is that more and more people begin to live as fragrance-free as possible. This is a very serious, debilitating, and life-changing condition. It is real, it has genuine causes, and very devastating consequences. It's time to stop debating about whether or not Chemical Sensitivities is "real" and start putting that energy into fixing the real problem. If we as a society don't decrease our use of fragrances and chemicals, the prevalence of this illness will continue to rise. People with CS are like the canaries used in coal mining - if they are getting sick, everyone else should pay attention.

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