Scented Products as Sources of VOCs: Implications for Susceptible Populations

Paper # 995

Presented at the 2005 AWMA Conference and Exhibition

June 2005

Betty Bridges

Fragranced Products Information Network, 12602 Reed Rock Road, Amelia, Virginia 23002

ABSTRACT

There is widespread use and exposure to scented products in homes, workplaces, and other public spaces. These products are often overlooked as sources of volatile compounds and contributors to indoor air pollution. Though many people are not aware of exposures or experience only minor irritation, certain populations are more likely to be negatively impacted by fragrance exposures. Sensitive and susceptible populations include those with migraines, allergies, asthma, and other respiratory disorders as well as the very young, the very old, and those of reproductive age. As volatile compounds, allergens, and respiratory irritants the materials used to scent products can trigger and exacerbate health conditions. Those that do not have immediate responses that can be correlated with exposure to scented products may not be aware that these products negatively impact their health. Those that experience immediate effects are acutely aware of the need to avoid exposures. However, avoidance is not easy as other’s use of scented products and use to clean and maintain environments makes avoidance difficult if not impossible. Further scented products are rarely perceived as being harmful to health except by those that experience negative health effects.

Though the accounts of negative health effects from exposures to scented products continues to rise, in relationship to use and exposure, the research is scant. As with any emerging health issue research lags far beyond patient and clinical accounts. A growing body of research supports both health and environmental concerns. It is not clear what specific materials are responsible or what mechanisms are involved. It is clear that scented products can negatively impact health, especially the health of sensitive populations. At present specific ingredients in the fragrance portion of products are not usually revealed and there are around 3000 fragrance materials in use. This makes it extremely difficult to pinpoint problematic materials. Additional research and industry cooperation are needed to explore what materials and mechanisms are involved. Educational programs are needed to increase awareness of health concerns related to scented products, especially for sensitive and susceptible populations.

INTRODUCTION

The quality of indoor air is an important health concern. Exposures to indoor air pollutants can cause acute effects such as irritation to eyes, nose, and throat, headaches, dizziness, and fatigue. People spend as much as 90% of their time inside. Populations that are the most likely to be negatively impacted by poor air quality such as the very young, the elderly, the chronically ill, those with allergies, migraines, respiratory, and cardiovascular disease are also those most likely to spend the most time indoors. Effects of chronic exposure to pollutants are less clear. There is growing evidence that poor air quality contributes to the development of some respiratory diseases, cardiovascular disease, and cancer.

There are many sources and type of pollutants in the indoor environment. Levels of volatile organic compounds (VOCs) are often 2-5 times higher indoors than out. VOCs are emitted from building materials, furnishings, and products used within indoor environments. Small particles that can be breathed deeply into the lungs are associated with acute exacerbation of respiratory and cardiovascular disease and with chronic effects.¹

Materials must volatilize and be airborne in order to be detected by the olfactory system. By design fragrance formulas are composed of such materials. Scented products are often overlooked as sources of volatile compounds and contributors to the formation of small particles in homes, workplaces, and other indoor environments. A scented product is one that has added fragrance to impart an odor to the product or mask the odor of other ingredients in the product. Fragrance materials may be natural, synthetic, or combinations.

Fragrance permeates our lives. In spite of such widespread use and exposure to products containing fragrance, its presence has become so ubiquitous that it often goes unnoticed.

The physiology of olfaction is such that the same odor is not detected for long periods of time. So users of scented products are often not aware of the presence or intensity of the fragrance in the scented products that they use. In order to have the same levels of awareness of the scent, increasing amounts may be used or products reapplied more frequently. Companies have routinely increased the intensity of the fragrance in their products so they will be noticed.

Sales of raw materials to flavor and scent products have increased from $12.9 billion in 1999 to an estimated $16.2 billion in 2003. About half of these raw materials are used to scent a wide array of consumer and industrial products. Approximately 25% of raw fragrance materials are used in perfumes and to scent cosmetic and toiletries. Around 75% are used in non-cosmetic applications.² Table 1 provides sales volumes of common scented products.

Table 1:    Annual sales of common scented products.

While any one individual source of fragrance may have limited impact on air quality, collectively they are significant sources of indoor air pollution. Millions of pounds of fragrance materials are used annually⁸ in indoor spaces in toiletries and cosmetics, cleaning products, environmental fragrance and other scented products. The use of fragrance has increased ten-fold since the 1950s and the sales of raw materials to scent products doubled during the 1980s.⁹

Because fragrance is used in so many products and the ingredients in the fragrance portion of the product are not generally disclosed, it is difficult to accurately assess exposures. Indirect measures such as volume of fragrance chemical use products provide insight into exposures.

Under the Inventory Update Rule, the US Environmental Protection Agency (EPA) requires companies to report every four years chemicals manufactured or imported into the US at levels of 10,000 pounds or more annually ¹⁰ Aggregate ranges are then compiled for each chemical.  Chemicals at one million pounds or more are considered to be High Production Volume Chemicals (HPV).¹¹ Despite widespread exposure to these materials, the majority of fragrance chemicals have limited available health and safety data. The EPA evaluated the HPV chemicals reported in 1990 for available toxicity data in six basic areas.¹² Industry was then asked to provide this basic data on these chemicals.

The 1990 HPV Challenge Program Chemical List was searched.¹³ The Flavor and Fragrance High Production Volume Consortia volunteered to provide data on 47 HPV chemicals indicating high or primary usage by the fragrance industry. Availability of basic toxicity data on these chemicals was obtained from the Master Summary Table, US High Production Volume Chemical Hazard Data Availability Study.¹⁴ Only one had available data in all six areas and over a third had no data available. Over 75 percent were missing three or more sets of data. Only one material had chronic toxicity data and over 75 percent were missing reproductive data. The basic areas of toxicity do not include effects on specific organs or systems such as the lungs or nervous system.

Tables 2 and 3 summarize findings.

Table 2:    Summary of available toxicity data in six basic areas for industry sponsored HPV flavor/fragrance materials.^13,14

There are around 3000 materials used by the fragrance industry and 80-90 percent are synthesized. The nine major starting materials for synthesis are turpentine oil, C2-C5 petrochemicals, benzene, phenol, toluene, xylenes, cresols, naphthalene, and cyclopentene.¹⁵

Table 3:    Specific areas data are available for industry sponsored HPV flavor/fragrance chemicals.^13,14

Many fragrance materials have no publicly available health and safety data. A 1999 analysis of a popular perfume revealed the material known by the trade name Iso E Super was the chemical at the highest level in the product.¹⁶ A literature review by the National Toxicology program of this material found it structurally similar to a chemical with known toxic effects in animal studies and there was no publicly available health and safety data. ¹⁷

There is wide spread exposure to multiple scented products in most indoor environments. Due to the volatile nature of these products, some of each product used by each person ends up in the air. Products are often designed with fragrance that is immediately diffusive and lingers in the air for long periods of time. There has been limited examination of the impact on indoor air quality and impact on health.  The available research is scattered and rarely viewed as a whole. This paper reviews and summarizes available data, reviews mechanisms that may be involved in adverse effects of fragrance, and discusses complicating factors and needed actions.

IMPACT ON INDOOR AIR

Perfumes and other products used primarily for their scent have gone from luxury, special occasion use to daily wear.  According to the EPA’s Exposure Factor Handbook, around 1/4 of the respondents applied perfume, cologne, or similar product 1-2 times daily. Around 5 percent of these used the products 3-5 times daily.¹⁸ While perfumes have traditionally been the strongest form of fragrance, other cosmetics and toiletries now have intense and long-lasting fragrance. Shampoos, soaps, body washes, deodorants, lotions, hairspray, and numerous other products that are used on a daily basis contain added fragrance.

Analysis of perfumes and scented toiletries reveal a number of volatile and semi-volatile chemicals make up the fragrance portion of the products. These include aldehydes, alcohols, terpenes, benzene derivatives, and phthalates.¹⁹ Some of these materials are heat, light, and air sensitive. They break down and mix with other materials in the air often forming compounds which are more toxic and irritating than the original materials.  

Cleaning and laundry products are heavily scented. The scent from detergents and fabric softeners can last for weeks. Residue from each washing builds up in clothing and provides a constant source of fragrance emissions which contribute to VOCs in the indoor environment.

The presence of odors is frequently cited as evidence of poor indoor air quality. Products that emit fragrance to cover up odors, commonly referred to as “air fresheners” are often used when offensive odors are present.  According to information at the EPA web site:

“Air fresheners work in one of the following four ways: by interfering with your ability to smell by way of a nerve-deadening agent; by coating your nasal passages with an undetectable oil film; by covering up one smell with another; and (rarely) by breaking down the offensive odor. Despite their name, air fresheners do little to freshen the air. Aerosol fresheners can be harmful to lungs if inhaled in high concentrations or for prolonged periods of time.”²⁰

EPA studies found pine scented plug-in air fresheners emitted a number of volatile compounds.²¹ These included alpha-pinene, thujone, camphene, beta-pinene, benzyl acetate, beta-myrcene, alpha-methyl benzyl acetate, benzaldehyde, benzyl propionate, 3-carene, bornyl acetate, limonene, isobornyl acetate, dipropylene glycol methyl ether, 4-carene, terpinolene, alpha-cedrene, benzyl alcohol, and lilial. Several other compounds were found, but not identified. Ozone was introduced into the emissions of the air fresheners. A number of new aldehyde compounds were formed including formaldehyde. There was also a significant increase in small particle formation from the reaction of the chemicals in the air fresheners and the ozone.  The levels of ozone used in these studies were higher than those normally found in homes. However, days of high ozone levels or use of an ozone-generating air cleaner can create similar levels of ozone. Consumers should be aware that use of scented products in combination with ozone-generation air cleaners can cause a significant rise in formation of small particles.

Use of aerosols and air fresheners are implicated as sources of volatile compounds²² and in formation of small particles of respirable size in other studies as well. Chamber tests were conducted on air fresheners and other consumer products with ozone found in ambient indoor air and with elevated levels. In all tests there were increases in the formation of small particles, with higher levels associated with higher ozone levels.²³ These tests confirm earlier findings that terpenes, which are common in air fresheners and other consumer products, react with ozone to form small particles in indoor environments.²⁴

Other forms of environmental fragrance also emit VOCs and contribute to the formation of small particles. Scented candles are a popular form of environmental fragrance. According to the National Candle Association 7 out of 10 households burn candles and two thirds of candle purchasers burn candles once or more a week. The average burning time per use is about 3 hours. ²⁵

Data from candle studies vary greatly.²⁶,²⁷ A number of variables affect how cleanly a candle burns such as conditions of wicks, air flow, containers, and composition of the candle. One candle may emit a hundred times more soot than another candle. Candles have been found to be sources of black carbon particulate matter commonly known as soot. The less cleanly a candle burns, the more soot is produced. When a candle burns normally in undisturbed air, emission of soot is very low. When there is disturbance in the air a candle can emit large quantities of soot.  Extinguishing a candle by depriving it of oxygen causes smoldering which also emits particles. Clipping the wick to extinguish the flame greatly decreases particle production.²⁸ Scented candles emit more particulate matter, soot, and organic compounds than unscented ones and the more scented oils in a candle, the less cleanly it is likely to burn.²⁹

Candle soot resembles diesel exhaust in particle size, absorbed soluble organic compounds and carbon core structure. Soot from scented candles can contain pthalates, benzene, and toluene. Volatile emissions include benzene, styrene, toluene, ethyl benzene, naphthalene, acetylaldehyde, benzaldehyde, benzene, ethanol, and methyl ethyl ketone. Candles may emit benzene and other volatiles if when unlit. If wicks contain lead, dangerous levels of lead can also be emitted from burning candles.³⁰

Polycyclic aromatic hydrocarbons (PAH) are often associated with incomplete combustion, however presence of PAH vary greatly in candle emissions and soot. Several studies have found no PAH in normally burning or smoldering candles, one study was unable to evaluate heavily sooting candles due to technical difficulties.^28,30 Other studies have found candles to emit PAH.^27,31,32

Incense is frequently burned ceremonially and in homes and is another potential source of particles and VOCs. The US market for incense is estimated to be at least $17 million annually. As with candles there are a large number of manufactures and the composition of incense may vary greatly. ^29,33

A number of studies establish incense as a significant source of PAH and small particles. An EPA study of 10 incenses found that all emitted significant amounts of PAH and small particles.³⁴ Other studies have found incense use in homes and temples created significant exposure to small particles and exposure to PAH.^32,35-37 Incense also emits a number of aldehydes such as formaldehyde and acrolein.³⁸  

Environmental fragrance is frequently encountered in homes, at work, places of worship, and other indoor environments. These products can significantly add to volatile compounds and fine particles in indoor air. Collectively these products are an important source of indoor air pollution in homes, workplaces, and other public spaces. Because these products are considered pleasant, users are often not aware they can negatively impact health the health of the occupants.

IMPLICATIONS FOR HEALTH

With widespread use and exposure to scented products, health concerns have emerged. There are numerous anecdotal and clinical accounts of adverse effects. The U.S Food and Drug Administration has in place a program for reporting complaints related to cosmetics. In the period from 1995 to 1998 approximately 4% of the complaints were on perfumes, colognes, and other products used primarily for their scent. From 1999 to 2003 almost 20% were complaints related to these same types of products. The majority of the complaints were related to respiratory and neurological effects. The Food and Drug Administration (FDA) estimates only a small fraction of adverse reactions to cosmetics are reported to them. It is not possible to ascertain from the FDA data if there are complaints related to the fragrance portion of other cosmetics or complaints from non-cosmetic exposures. ³⁹

A Medline search using the search terms "perfume OR perfumes OR fragrance OR fragrances" pulls up 1452 citations, the majority of which are on physiological, health and environmental aspects of fragrance.⁴⁰ Over half has been published in the past ten years and over a third has been published in the past five years. While the largest amount of literature is on skin effects, the literature that raises respiratory, neurological, reproductive, and systemic concerns is growing. In spite of increased documentation indexed in Medline and in other sources of information, in relationship to use and exposure, the data is sparse.

Once fragrance chemicals are in the air, they enter the body in a number of ways. The primary route is via the respiratory system as they are inhaled into the lungs. However, there is skin contact as well and those that have severe allergies can experience dermatitis and other adverse effects through airborne contact.⁴¹ As airways filter and trap materials to prevent entry into the lungs, secretions are swallowed and there is exposure through ingestion. Airborne materials settle on surfaces and are found in dust. Hand to mouth contact is an important route of exposure to infants and children. Once substances are in contact with or in the body, there is potential for health effects.

Respiratory

The airways and lungs are exposed to any materials that are present in the air. Scented products are common sources of volatile organic compounds (VOCs) in ambient indoor air. Anecdotal and clinical accounts of adverse respiratory effects of exposures to scented products are common. Fragrance is frequently cited as triggering and exacerbating conditions such as asthma, allergies, rhinitis, laryngitis, emphysema, and other disorders that affect breathing. Virtually every organization and agency concerned with respiratory health list fragrance as a trigger for asthma.^42-45

However there are limited studies on the respiratory effects of scented products or individual fragrance chemicals. Adding “AND asthma to the previously Medline Search pulls up 46 citations. In a survey of asthmatics that reported odors worsened their asthma, 72% cited perfumes and colognes as triggers. Four patients with a history of cologne worsening their asthma underwent challenge tests with pulmonary testing before, during, and after the exposure to cologne. Forced expiratory volume in one second (FV1) declined 18-58% during the 10 minute exposure.⁴⁶

Twenty-nine asthmatics and 13 control subjects were challenged with perfume strips from magazines, perfume identical to that in the strips on filter paper, isopropyl alcohol, and saline. Pulmonary function studies were done before and after the challenge. Symptoms of chest tightness and wheezing occurred in 20.7% of the asthmatics exposed to perfumes with severe asthmatics being most likely affected.⁴⁷

Recent epidemiology studies show an occupational link between cleaner exposure and asthma.^48-52 Exposure to cleaners and other household chemical use is linked to wheezing in children.⁵³ Irritant and allergic reactions to cleaners are also common. Exposures to cleaners occur through skin contact and via inhalation.

Asthma rates are higher in occupations that involve cleaning. Data from state-based surveillance of work related asthma found that 12% of work-related asthma causes were associated with exposure to cleaning products. Women working in a medical settings cleaning or as nurses/nurses' aides were the most likely to be affected.⁴⁸ Zock, et al. found domestic house cleaners had the highest incidence of asthma.⁵² Women have traditionally have had primary responsibility for household cleaning. Asthma rates for women in general have increased as well and cleaners are suspected as having a role.⁴⁹ 

Terpenes are common in cleaners both as active ingredients and as added fragrance. Oxidation of terpenes form peroxides and other materials that are more irritating and harmful than the original substance.⁵⁴ Limonene, when oxidized forms sensitizers and irritants which can cause increased respiratory sensitivity to other irritants.⁵⁵ These materials can also increase the absorption of other materials into the skin.⁵⁶

 A number of materials used in cleaners such as solvents, bleach, and ammonia are known to be irritating to the respiratory system. Enzymes used in cleaners and laundry products can cause sensitization and allergic reactions. While these ingredients certainly have a role in asthma, they fail to fully account for the recent link of cleaners and asthma. It is likely that other ingredients such as fragrance in the cleaners play a role as well. There are anecdotal accounts of the fragrance in cleaners triggering asthma, however further research is needed to determine the role fragrances play.

Laundry products pose particular concerns. There is continual exposure as clothing are worn and in constant contact with large areas of the skin. Residual fragrance from washing and drying lasts for weeks and build up of fragrance occurs each time they are laundered. Musk xylene is known to accumulate in human tissue. A German study compared plasma concentration of musk xylene from 1992-93 to those from 1998. There was considerable decrease in levels which corresponded with the banning of musk xylene in Germany in1993.⁵⁷

Mice were exposed to emissions from fabric softeners. Exposure caused acute changes in the respiratory cycle including sensory irritation, pulmonary irritation, and airflow limitations. Exposure to laundry dried using one fabric softener also caused sensory irritation.⁵⁸ Mucosal irritation is reported from exposure to scented products such as freshly laundered clothes and air fresheners.