OVERVIEW

Increasingly there are complaints of perfumes and fragranced products causing or contributing to health problems such as asthma, migraines, and upper respiratory irritation. Is this simply a reaction to the odor of these products or should it be a serious concern?

Information on fragrances and the chemicals used in them is not readily available. Fragrance formulas are trade secrets and ingredients do not have to be listed on the labels. There have been few medical studies done other than on the effects of fragrances on the skin. The goal of this site is to gather available information and make it accessible.

Where possible there are links to online information sources so they can be easily accessed for those interested. But not all are available on-line. Most of the sources are from the chemical or fragrance industries, government sources, or medical literature. Links are provided to PubMed where abstracts of medical studies are available.

CHEMICAL RECEPTION

TOLERANCES AND INDIVIDUAL RESPONSE

TRENDS IN THE FRAGRANCE INDUSTRY

FRAGRANCE MATERIALS

SAFETY OF FRAGRANCE MATERIALS

DERMATOLOGICAL EFFECTS

RESPIRATORY CONSIDERATIONS

NEUROLOGICAL EFFECTS

OTHER HEALTH CONSIDERATIONS

COPING WITH SENSITIVITIES TO FRAGRANCES

CHEMICAL RECEPTION

In order to understand how chemicals we breathe in can affect us it must be understood how odor is detected and the pathways that are involved. There is much more than the scent of a substance involved. The sense of smell is one of the most primitive senses. It is actually a reception of chemicals in very specialized cells in the nose and the olfactory cells. Exactly how the odor is perceived and processed in the brain is not well understood. But it is known that of all the senses, smell has the most direct connection to the brain.

Odor and chemical detection is essential in the survival of most life. In animals it is essential for finding food, mating, and protection. In humans its value to basic survival has decreased as our lives are less dependent on being able to hunt and escape being hunted. Odor detection is often thought of as being a sense that enhances our lives, but is not all that necessary.

In recent years there has been a surge in interest in the sense of smell and the olfactory system. It is now realized that perception of odors and chemical reception through the olfactory system affects us in many subtle ways. It is a continual ongoing process that is often over looked. And the effects of this chemoreception are very complicated. There is an intricate web of both the physical and the psychological that is impossible to separate.

The odor of baking bread may bring back a flood of warm memories if one' s mom or grandmother baked bread. Or it may stimulate the appetite causing and increase in gastric juices. An odor can trigger memories from childhood that are pleasant or very unpleasant. And with the memory may come a gamete of emotions and physical effects. Pulse, blood pressure, and many other physical aspects of the body may be affected.

Many think of odor and its interpretation as a psychological process and others will argue that it is a physical one. Both are right. It is an intertwined process that both affects the physical and the psychological and it is often nearly impossible to separate where one ends and the other begins.

It is well known that during pregnancy many odors that were perceived as pleasant or neutral before will cause nausea. This is a physical change. After pregnancy the aversion to these odors usually disappears. When ill one is much more sensitive to odors. Again when the illness is over this sensitivity usually goes away.

It has been found that breathing in certain chemicals have effects that go way beyond odor detection. Tests in animals have shown that there are definite physical changes that occur. And while a chemical may have a particular odor, it is not the odor or the perception of that odor that causes these changes. The chemical itself affects body processes.

These changes that occur are well known when certain chemicals are inhaled. Inhaling solvents and petroleum products whether deliberately or accidental can cause serious harm. It is not the odor that causes the problem even though the substance may have a distinctive odor. Inhaling propane gas will cause illness and death. Propane gas actually has little to no odor and an odorant is added to enable people to know they are being exposed.

Usually things that have a pleasant odor are thought of being good and those that have an unpleasant odor are thought of being harmful. While this is true in some cases, it is not always necessarily so. Many solvents have a sweetish odor that is not unpleasant, but they will still cause serious health problems when inhaled.

One more interesting aspect of odor perception, the olfactory cells tire very easily. And when exposed to an odor for a period of time the perception of the odor is diminished. So while someone that uses the fragrance may not be able to detect the odor it would be quite apparent to others that do not use the fragrance. Someone that does not use fragranced products is much more aware when others use them. This is not necessarily that their sense of smell is better in general, but rather their perception of that particular odor is not dulled because they are not constantly exposed to it.


TOLERANCES AND INDIVIDUAL RESPONSES

The human body is quite amazing. It tolerates exposure to many substances in a day's time. There are many factors that determine what will be tolerated without adverse effects and what will not. And those tolerances will vary from individual to individual. There may be variations in tolerance in the same individual depending on other factors involved.

In general the healthier a person is the more tolerance there is toward less than optimal conditions. A healthy person can tolerate much more exposure than some one that is in poor health. Even a healthy person is more at risk when he or she is tired or stressed.

Age also effects tolerance. The very young and the very old are more at risk. The young because many of the systems of the body are still developing. Many of the defense mechanisms are not yet fully operational. Children and infants breathe at a faster rate and they are smaller. The rate of exposure in relationship to body weight is greater. When a child and an adult is exposed to the same thing the exposure is greater for the child. And a child's skin is thinner. This means that substances are more easily absorbed through the skin.

Also a child is often in closer proximity to the source than an adult is. Children crawl on the floor and so are more exposed to products used on the floors than an adult walking around in the room. When babies are held their faces are often very close to the hair and clothing of the person hold them. Their noses are closer to the fragranced product than the person's nose that is actually using the products.

In the elderly health is often compromised. Body processes do not work quite as well as they did at one point. Skin is usually thinner because of the loss of the fat layer beneath the skin. So substances are more easily absorbed through the skin.

Women are usually more prone to problems from fragranced products for various reasons. When compared to men women are usually smaller in size. This means the same exposure would be a higher dose for women. And women have a higher ratio of body fat then men do. Many chemicals are stored in fat tissue. One a substance is in the fat tissue it can remain in the body for a long time.

Also women are generally exposed to fragranced products more then men. Most household products are fragranced. The fragrance materials are inhaled and they are absorbed through the skin. Along with this, women's personal care products are usually more perfumed than men's, although this trend is quickly changing.

Individual and genetic factors also play an important role. Just as some people can tolerate more sun than others, some people can tolerate more chemical exposure than others. Individual body chemistry varies and so does tolerance to chemicals.

It often takes repeated exposures in order for sensitivities to develop. It may seem that things that have been tolerated for years suddenly causes problems. Often sensitivities develop long before they are recognized. It is often difficult to pinpoint the cause of symptoms such as sinus problems, skin irritations, and triggers for asthma. This is especially true when the triggering substance is one that is common in the environment.
 

TRENDS IN THE FRAGRANCE INDUSTRY

In the past few decades the use of fragranced products has soared. Some thirty years ago most soaps had an odor that was recognized as soap. There was a usual odor associated with detergents and most cleaners had either a lemon or a pine odor. Perfumes were only used for special occasions and most personal care products were either mildly scented or not scented at all.

This is no longer the case. Each brand of laundry detergent has it own specific scent and that scent is advertised as lasting for days. The fragrance of a product has become its main selling feature and whole advertising campaigns are built around the odor of a product. Trash bags and even flowerpots now come in scented versions.

On a daily basis most people use more than a half dozen or more scented products without ever applying perfume or cologne. Virtually all fragrance chemicals are volatile compounds. Each person leaves a little bit of each of their fragranced products behind in the air wherever they go. When this use is multiplied times the number of people in an office or crowded public places the exposure is phenomenal. Couple this with inadequate air circulation of many modern buildings and the problem increases.

And in the past few decades there has been not only more fragranced products, but also more heavily scented products. Modern fragrances are much more powerful and last much longer than those in the past. It used to be that perfumes were the most lingering of fragranced products. A good perfume would last 6-8 hours. Now detergents are formulated for the scent to last on the clothes for days after they are washed. Lotions have longer lasting fragrance than perfumes did in the past.

This trend toward more powerful and long lasting fragrances has been brought about in several ways. The materials used are much more intense and longer lasting than those in the past. Often these more powerful materials are used in greater quantities in a formula. Three or four materials may make up the majority of the fragrance formula. This makes for a very powerful and long lasting fragrance.


FRAGRANCE MATERIALS

The large majority of fragrance chemicals are synthetic compounds, with the majority being synthesized from petroleum products. Over 80-90% of all fragrance chemicals are synthetic. Synthetic chemicals are used in the fragrance industry because of availability and cost factors. Also using synthetics allow scents not found in nature to be created. It would be impossible to produce perfumes with the intensity and staying power of modern fragrances using all natural materials.

While a chemical is considered the same whether found in nature or synthesized in the lab, there are some differences. Reaction processes produce chemicals in the lab. Trace amounts remain of the chemicals used and the resulting chemical is not pure. These trace impurities affect the odor quality of the materials. Materials derived from natural materials also contain trace amounts of other chemicals that are found in the original source. So although the main chemical may be the same, the odor quality of materials derived synthetically may be very different than those derived from natural materials.

In the fragrance industry natural materials are considered to be those obtained from plants and animals. But this can be very misleading. In nature certain chemicals are usually found together. For instance citral by itself has a greater potential for skin irritation than when used with limonene. In nature citral occurs along with limonene. So while citral obtained from a plant source would be considered "natural", it may have a very different effect on the skin than an essential oil that contains all of the chemicals derived from the original source.


SAFETY OF FRAGRANCE MATERIALS

To further complicate matters it is not accurate to say that a " natural" material is safer than a synthetic one. Many of the best known sensitizes are materials found in nature. Balsam of Peru, Oakmoss absolute, and Costus oil are natural materials whose use should be restricted for reasons of safety. Many of these natural essential oils, absolutes and concretes have been used for centuries and because of this use more information is available on their adverse effects. Many essential oils have known health risks. It is foolish to equate "natural" with harmless. Any such material that has potential for positive effects also has potential for negative effects.

There is much less history of the effects of the singular chemicals without the companion chemicals that are usually found in nature. Most of these and those synthesized in the lab have only been in widespread use in the last few decades. Very little testing has been done on these chemicals.

MSDS and chemical information on these chemicals often state:

"THE CHEMICAL, PHYSICAL, AND TOXICOLOGICAL PROPERTIES HAVE NOT BEEN THOROUGHLY INVESTIGATED"

Label precautions often list these chemicals as both skin and respiratory irritants. Skin and respiratory protection is recommended.

Fragrance chemicals are often heat, light, and air sensitive. They break down in the air. Very often the resulting chemicals are more irritating than the original compound. And the chemicals can combine with others in the air to form totally new compounds. So what is in the air is constantly changing. In detergents more than 80% of phenylacetaldehyde is diffused through cardboard containers after 24 weeks on the shelf. As much as 100% of citral may be lost. The diffusion of these chemicals into the air is responsible for the "detergent aisle" odor.

Some fragrance chemicals are hydroscopic. The safety of fragrance chemicals has not been established individually, even less information is available on the effects of combinations of sometimes hundreds of different substances.


DERMATOLOGICAL EFFECTS

Fragrance chemicals are frequent causes of dermatological problems. The fragrance portion of laundry products and cosmetics is the number one cause of allergic and irritant skin reactions to those products. The majority of times these are local reactions and require contact with the product. However there have been some instances of dermatitis from airborne materials and actually physical contact with the product never occurred. Generalized rashes may also occur in sensitive individuals.

Many fragrance materials can cause photosensitivity. This is of special concern in sunscreen products that contain fragrance. Those materials that have to potential to cause photosensitivity or phototoxicity should not be used in products such as lotions or sunscreens that are used on areas that have exposure to the sun.

While generally one only thinks about what is applied to the skin as only affecting the skin, this is not true. Fragrance chemicals penetrate the skin and thus can affect other organs. Studies have shown that cinnamaldehyde binds with proteins in the skin to cause allergic reactions. It is also found that some fragrance materials are absorbed by the skin and then broken down into materials that are stronger sensitizers than the original chemicals.


RESPIRATORY CONSIDERATIONS

While many fragrance chemicals are known skin sensitizes, there have been very few studies specifically on the effects of fragrance chemicals on the lungs. There is debate and discussion on whether fragrance chemicals are irritants that exacerbate attacks or are they are sensitizers and primary causes of asthma. There is more information on chemicals such as acetaldehyde that are also used in other industries then there is on chemicals specific to the fragrance and flavors industry. Most of the fragrance chemicals have not had testing done to determine their impact on the respiratory and immune systems.

One study that was done showed that the perfume strips in magazines were triggers for asthma. Another study showed that asthma like symptoms were triggered by fragrance chemicals. This study showed that the symptoms were triggered even when the participants could not detect the odor. It also pointed out that carbon masks while filtering out odor, did not prevent the symptoms.

Virtually all of the chemicals used in fragrances are volatile organic compounds. These types of chemicals are known to be respiratory irritants. They are often unstable chemicals that are air, light, and heat sensitive. This means they break down in the air, often to more dangerous compounds. The components in the air that can constantly change.

A fragrance formula may contain as few as 10-15 ingredients or as many as several hundred. Some perfumes are said to have 600-800 ingredients. In perfumes the fragrance materials generally make up 20-25% of the finished products. In other consumer products the percentage of fragrance in a product is much less.

The percentage of any one material is usually very low, so thought to be safe. However, recent studies have shown that some materials potentate the effects of others. So mixtures may pose a health hazard many times that of the individual ingredients. Also if all of the ingredients are respiratory irritants the effect would be a cumulative one of all the chemicals.

Cinnamaldehyde has been shown to have act as a hapten in the skin. As respiratory exposure to fragrance chemicals is great this potential needs to be considered. There are anecdotal accounts of respiratory sensitization to specific fragrance chemicals. Fragrance chemicals are everywhere in the environment. If they cause Occupational Asthma the implication are serious. The connection between the increased asthma rates and the tremendous surge in the use of fragranced products over the past several decades needs to be examined.

Many of the same aldehydes and other chemicals targeted as having effects on the respiratory system in cigarettes are fragrance chemicals that are added to enhance flavor. These chemicals are connected with the increased asthma rates of children in homes of smokers. If these chemicals are harmful in cigarettes they would certainly be harmful in other consumer products.

At the very least fragranced products are triggers for the asthmatic because or irritation to hyperactive airways. Products used by others can be detrimental to asthmatics and can seriously affect their health. And they seriously impact the air quality in homes, offices, schools, and other public places. And there is real potential that they are much more than irritants, and may be the primary cause of asthma in some individuals.


NEUROLOGICAL ASPECTS

The nose is a chemical receptor. When you detect the odor of something you are detecting the chemicals that make up that odor. The sense of smell has a more direct connection to the brain than any other sense. There is no barrier between the brain and the chemicals that you breathe in. While it is well known the effects of "snorting" cocaine, little thought is given to the effects of the other chemicals that pass through our nasal passages.

Studies have shown that inhaling fragrance chemicals can cause circulatory changes in the brain. Changes in electrical activity in the brain also occur with exposure. Fragrances are a frequent trigger of migraine headaches. Changes in circulatory and electrical activity in the brain can trigger migraines in susceptible individuals.

One study showed that motility in mice was decreased by 30% when exposed to some fragrance chemicals. This effect was present even when stimulated with caffeine. This is a significant consideration that affects health, safety, as well as productivity on the job.

AETT was found to be neurotoxic and it was found to be absorbed through the skin. AETT was frequently used in "fragrance free" products. Musk Amberette was also found to cause neurological problems in animals and should not be used in fragranced products.
 

OTHER HEALTH CONSIDERATIONS

Since fragrance chemicals are absorbed through the skin they can and do affect other organs of the body. AETT was found to cause discoloration in internal organs. Some of these chemicals are toxic to the liver and kidneys. Others accumulate in fat tissue.
Synthetic musk compounds have been found in the water supply of urban areas. It is thought that the use of fragranced laundry products, household products, and personal hygiene products such as shampoos has contaminated the water supply. These chemicals are not filtered out by water processing methods and thus what goes down the drain ends up in drinking water. These compounds are being found in fat tissue and breast milk. Only a few studies have been done and the long-term effects are not known. The safety of these chemicals has not been established.