What is MCS


Multiple Chemical Sensitivity

Multiple Chemical Sensitivity (MCS) is a chronic, physical illness affecting people of all ages and backgrounds. It causes sufferers to have allergic-type reactions to very low levels of chemicals in everyday products. Put simply the immune and detoxification systems stop working properly and the body cannot process toxins efficiently.

Besides reacting to things like cleaning products, shampoo, perfumes and pesticides, many sufferers are also sensitive to food, medicines, moulds and electromagnetic fields.

Who gets MCS?

MCS is a devastating and isolating illness that has many different triggers and can start at any age. It may develop after a single particular exposure to a toxic substance such as pesticides or industrial solvents (sometimes from a newly decorated home or office). Others develop sensitivities after a period of ill health or viral infection, with symptoms getting worse over several years.

Occasionally the illness arises gradually as a result of long term exposure to very low level toxins. Once sensitised, individuals often react to minute traces of chemicals at levels far below those usually considered to be harmful.

Some airborne irritants are odourless and sufferers may find themselves in the distressing position of having no idea what they are reacting to. Severe reactions can leave sufferers bedbound for several months, while many more become confined to their homes.

In 2003, research indicated over 12% of the US population was affected with MCS – over 36.5 million people – and statistics have continued to rise. Exact numbers of sufferers in the UK are still not known but include thousands of soldiers affected by Gulf War Syndrome. Despite this, the medical profession still varies widely in its support and there are currently no clinical guidelines for the treatment of patients.

The modern environment is becoming increasingly polluted with chemicals and electrical emissions. Studies indicate that many products contribute to the total body load that we have to process and eliminate every day including cleaners and disinfectants, phthalates in plastics, flame retardants in furniture, formaldehyde in furniture, decorating products, fragrances and pesticides. Low level microwave radiation is increasing rapidly and each time signals strengthen, more people develop Electro-Hypersensitivities (EHS).

Emerging scientific research is raising the level of concern about the health impacts of these exposures. Those of us that have weakened immune and detoxification systems are already feeling the effects as our bodies are no longer able to process the toxins (xenobiotics). Those of us struggling to live with Environmental Illness (EI) have no choice but to avoid the things that trigger symptoms. People with MCS are often referred to as canaries after the birds miners used to warn them of poisonous gases.

Symptoms of MCS

Most people are familiar with mild forms of chemical sensitivity. Symptoms might include a rash from washing powder or shampoo, headaches from traffic fumes, asthma from perfume, or hyperactivity induced by chemicals in foods. These symptoms can usually be managed by avoiding the problem products.

Individuals with MCS react to far more than one or two items. Severe sufferers cannot tolerate any synthetic or petrochemical substances, and some even react to natural products. Because of modern manufacture, many people with MCS find themselves allergic to practically everything in their homes.

Exposure to very low levels of toxins and fragrances can lead to a wide range of symptoms including headaches, nausea, disorientation, confusion, breathing problems, exhaustion, muscle pains or collapse. Reactions vary in severity and can occur immediately or several hours later depending on which body systems are involved.

MCS affects family, relationships, employment, social interaction, and even simple things such as taking a bath, getting dressed or reading a book. Hypersensitive individuals may become intolerant of a great many foods and some find themselves unable to tolerate anything except liquid nutritional feeds. Others become sensitive to electromagnetic fields and are unable to use a telephone, computer, radio or TV – effectively becoming housebound without any form of outside communication.


Although symptoms can be managed and sometimes improved, there is currently no known cure.

Recovery involves avoidance of as many toxins and problem substances as practicably possible, to allow the body time to heal and prevent irreversible damage. This has a huge impact on everyday life but nutritional therapy and gentle detoxification can help repair the body’s systems. Some people also find specialist desensitisation and complementary therapies beneficial.

The easiest way to diagnose chemical sensitivity is to keep a Diary of symptoms, activities and what you eat or drink. After a couple of weeks look back and see if you can identify any recurring patterns. Once you’ve worked out what’s triggering your symptoms, avoiding the product should help you feel a lot better. There’s no need to go without, simply replace the item with an alternative. “Fragrance-free” and “environmentally-friendly” brands are less likely to contain allergic triggers

Early access to appropriate information, support, treatment and an individual approach is vital for any chance of recovery.


MCS is not yet classified as a physical illness by the World Health Organisation (WHO). MCS is recognised in Germany, Denmark, Spain, Austria, Switzerland, Japan and several other countries, where sufferers sometimes have access to appropriate medical treatment, housing and social support (although this is often not the case).

In the UK multiple sensitivities are listed as a symptom of ME, but MCS is not yet recognised as an illness in its own right. Medical support varies widely and there are no specialist NHS treatment facilities. Sufferers and their families are often left to cope as best they can without help – this is where we can make a difference!

What can be done?

First of all make sure your environment contains as few toxins as possible. Consider your diet, water and particularly the room you sleep in. Stop wearing perfume or aftershave and get rid of air-fresheners. Changing your laundry detergent and toiletries can make a significant difference. You can download a list of toiletries and cleaning products that are likely to be suitable form our leaflet: ‘How to be Fragrance Free’.

Do you need to consider your environment and diet if you only have electro sensitivity?  Yes. There is no miracle cure for either of these conditions and improving one aspect of your health will generally help you overall. Correcting leaky gut, and candida for example can make a big difference to both chemical and electro-sensitivities.

At work or school ask if they will introduce a fragrance-free policy for staff/ pupils. Make sure the room is well ventilated and don’t sit near the photocopier if you react to the fumes or electrical fields. Ideally open a window or if the air is too polluted invest in an air purifier. If you subscribe to our membership service you can request a help sheet about air purifiers. Cabled internet will be less likely to exacerbate symptoms than Wi-Fi. Jobs that involve chemicals such as decorating, hairdressing or farming are likely to exacerbate symptoms and you will need to think carefully about how to limit this.

When you have removed the things you react to (as much as is practical) then start thinking about how to improve your immune and detoxification systems. An experienced practitioner can help you with this. Subscribers can request a list of practitioners in the UK. There is no one method of treatment that suits everyone, as there are several different reasons you may have developed MCS. This means you have to learn about treatment options yourself and work with practitioners and qualified nutritional therapists to see what works for you. If illness or allergies run in your family then a DNA test may help to discover the root cause. You can then work with a practitioner to compensate for any issues with nutritional supplements. Probiotics are also worth investigating and there are certain supplements like magnesium, multi vitamins, B complexes and vitamin D3 that can help. When you have taken steps to repair your detoxification pathways it is time to start gently detoxifying.

When your body can’t process toxins (xenobiotics) it will store them in your body until an occasion when it is able to process them. If you start detoxifying before you have repaired your pathways then you will simply loosen the toxins and they will circulate in your bloodstream until they can be stored again. This makes you feel awful, with headaches, flu symptoms, rashes etc.  People with MCS often have a low tolerance for nutritional supplements and medicines for this reason. This applies to massage, saunas, and even a capsule of probiotics can wreak havoc if it is too much too soon (as it will kill off the ‘bad’ bacteria causing an increase in toxins). When we talk about ‘gently detoxifying’ we mean start any treatment at a low dose/ less time and see how you are. You cannot speed up this process. Your body will only be able to process and get rid of toxins at a certain rate.

There is much more information about the process of recovery and treatments in our help sheets and you can read more about this here.

  • Caress, S. and Steinemann, A. (2003). More than 12% of Population Reports Extreme Sensitivity to Low Levels of Common Chemicals. Published in Environmental Health Perspectives (EHP), the journal of the National Institute of Environmental Health Sciences, 11 September 2003 Retrieved 18/02/05, from http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1241652/