Chemophobia is an irrational fear of chemicals, particularly synthetic chemicals used in the food industry, industrial processes, and drug making (legal and illegal). This fear of chemicals is often perpetrated by the media and environmentalists.
Commonly targeted chemicals
Many artificial sweeteners, such as cyclamate, aspartame, sucralose, have been repeatedly considered to have negative effects on health, ranging from irritations, to cancer, and as such have been banned from use in foods. Aspartame is considered one of the most studied and vetted food additives in the entire world, and all studies so far have not shown any negative effects and certainly no cancer or other claimed negative effects, while studies that claim negative effects have not been successfully replicated.
"Whole food" advocates have repeatedly and misleadingly stated that ascorbic acid created in a lab is not the same as the vitamin C found in foods, because it lacks certain specific cofactors that make up a "C complex." Thousands of studies have shown that L-ascorbate is sufficient and necessary to meet vitamin C requirements in the body. If this weren't true, all patients on parenteral nutrition would have died from scurvy due to the lack of a "C complex."
Azodicarbonamide is a preservative used in bread as a flour bleaching agent and an improving agent. In the US and Canada it is generally recognized as safe in concentrations less than 45 parts per million. However, a blogger known as "The Food Babe" successfully pressured Subway to phase out the product, arguing that the chemical is also used in shoes and yoga mats. While there are alternatives to azodicarbonamide, there was no reason to remove it from bread.
Commonly known as water, the use of this systematic name scares environmentalists. Numerous websites parody the aversion to chemical names, describing the material as being "able to cause burns in the vapor state and frostbite when solid," a reference to steam burns and other thermal injuries that have nothing to do with the water itself.
Playing off of this prank almost cost two radio talk show hosts their jobs, and they almost faced felony charges, but luckily these were dropped.
Often called MSG, monosodium glutamate is used to increase the umami flavor of foods. In the 1980s, a report of "Chinese restaurant syndrome" considered several sources of the symptoms, but MSG was singled out as the cause. Repeated studies have shown that MSG has no adverse effects in moderation, and glutamate as an amino acid is an important component of proteins.
Sulfuric acid has been used in several acid attacks that cause extreme pain and disfigurement to the victim. While it is an extremely useful reagent to chemists and non-chemists (as battery acid and drain cleaner), pushes have been made to ban or severely restrict its acquisition, and the media isn't helping either.
The majority of acid attacks occur in South Asia and the Middle East. Most victims in these areas are women, but in more developed countries, like the United Kingdom, men are far more likely than women to be victims of such an attack.
Natural vs. synthetic chemicals
Many people have advocated the use of "natural" products, saying that artificial ones are somehow different from their natural counterparts and may have adverse effects ("appeal to nature"). Many companies have caved into the pressure and removed certain targeted chemicals from their products, most recently azodicarbonamide and brominated vegetable oil, not because they are dangerous, but to improve consumer perception of the product.
People who want to "ban chemicals" often do not realize that everything is a chemical, and that natural and synthetic chemicals behave exactly the same because the arrangements of atoms and the atoms themselves are effectively identical.
These people also fail to consider that quite a lot of compounds and materials that originate directly from nature and have been or are still used are quite toxic and dangerous for health, such as asbestos, fine silica sand, hydrogen sulfide, ozone, volcanic emissions, etc. Likewise, a great majority of organisms, both plants and animals contain a variety of extremely toxic and even deadly compounds, some even without any known antidote, such as ricin (from castor beans), α-amanitin (Amanita genus mushrooms), saxitoxin (from certain shellfish), as well as various toxins from many microorganisms, like tetanus, botulism, anthrax, diphtheria etc. Most common plants, both vegetables and decorative are quite poisonous, and yet many people have no problem having an oleander in their garden, even though you can poison yourself through touch. Likewise, the most toxic compound known to man is the botulinum toxin, which you can get it from almost spoiled canned food, whereas the most carcinogenic compound, aflatoxin B1, can be found in Aspergillus mold, which tends to grow pretty much everywhere (cereals, tree nut shells tend to be good growth environment), and pretty much everyone has entered in contact with at least a small amount of it. Yet you don't hear people complaining about the latter.
Drugs and Explosives "Precursors"
Oftentimes, legislatures will pass laws that restrict the sales of chemicals that they deem to be useful in the manufacture of drugs or explosives. Unfortunately, many of these chemicals are very useful for amateur chemists. Some jurisdictions are worse than others when it comes to how they enforce these precursor laws.
One particularly shameful example is Texas, which since 1987 has required reisdents to apply for a permit to own not only drug precursor chemicals, but glassware that has been deemed as being "designed, made, or adapted to manufacture a controlled substance," which is completely untrue of most pieces on their list, such as Erlenmeyer flasks, condensers, and Büchner funnels. To receive a permit, one must submit a lengthy application form including an account of exactly how the chemicals or equipment are to be used, and allow a police officer to inspect their home. This permit is only valid for a single transaction.