Chemicals in Aerosol Packaging
Forget everything you may think you know about aerosol packaging and the chemicals used in the containers. Each one has a particular purpose in the final result, and now, those chemicals are greener than ever. Environmental movements have fostered the development of products that do not cause harm to the planet. With the market for aerosol goods on the rise, preventing damage to the Earth has become vital.
Thanks to innovations in packaging, the chemicals used in aerosol containers today are safer than the ones used in the past. Before the 1980s, chlorofluorocarbons (CFCs) were used as propellants in aerosol packing. This ozone-depleting chemical fell out of favor, replaced by more environmentally-conscious alternatives. Aerosol containers deliver their unique spray thanks to the unique blend of chemicals used in the packaging.
In this article you will learn:
Types of Aerosol Products
Aerosols come in a variety of forms, based on the kind of spray they create. The number of industries that use aerosols is as varied as the goods available. From their innocuous origins, aerosols have emerged as a preferred container for many industries and businesses.
History of Aerosols
The technology behind aerosol cans dates to 1790. These forerunners of today's spray cans did not closely resemble their modern descendants. These aerosols were not constructed of metal cans with the propellants we use today. The first models used self-pressurized carbon in beverages, much like today's sodas. By 1837, Perpigna created a valve-containing soda siphon. Early aerosol sprayers were not made of metal until 1862 when steel cans too large for practical use were first tested. The aerosol can as we know it would not be introduced until 1927.
In 1927, Norwegian Eric — also spelled Erik — Rotheim filed the patent for the first aerosol container that included a valve and propellants inside. This self-contained sprayer paved the way for fluorocarbon-propelled aerosols used for malaria control in 1943. Though the sprayers used during World War II were not available to the public, yet, their inventor, Robert Abplanalp, did create many ways to allow for cheaper, safer aerosol products for household use, including the crimp-on valve.
By the 1950s, Abplanalp's inventions and improvements, as well as the use of aluminum in the cans’ construction, allowed aerosol products to be sold to the public. Abplanalp’s company, Precision Valve Corporation, had a production rate of over 1.5 billion aerosol cans annually, earning it $100 million each year.
Soon environmentalists discovered the popular propellant of the time, chlorofluorocarbons, caused ozone layer depletion. Abplanalp took his design back to the drawing board to develop a safer propellant. Today, companies use the water-soluble hydrocarbon propellant he discovered. This liquefied gas makes aerosol products safer for use today than they have ever been before.
Aerosol Product Varieties
Aerosols are used in products for commercial, industrial, and consumer use. You can break down the product types by the aerosol classifications:
- Space Sprays: Space sprays produce fine particles of spray. These types of sprays
include room deodorizers, disinfectant sprays, and insecticides.
- Surface Coats: Surface coats do not produce as fine a mist as space sprays. The
larger particle size in surface coats allows for aerosols to spray out wet products such
as hair spray, topical medicines, spray-on deodorant, spray-on sunscreen, and powder
- Foams: As the name suggests, foams produce thick outputs. Shaving cream is
one of the most common types of foam aerosols.
Industries Making Aerosol Products
Aerosols are produced by several industries, with many applications. Thanks to rising consumer demand and opening markets, aerosols will expand in their applications and the number of sectors producing them.
Household chemical producers make air fresheners, surface disinfectants, and home insecticide products for consumer use.
Inhaled medications such as those for asthma are one use of aerosols in the pharmaceutical industry.
Personal care goods are increasing with the rise in the manufacturing of spray deodorants, hair spray, powder sprays, and dry shampoo. Foam goods such as shaving cream are another type of aerosol personal care item.
Chemicals in Aerosol Packaging
The chemicals used in aerosol packaging have specific reasons for their inclusion. Some provide aroma while others enhance the propulsion of the active ingredient.
How the final result appears depends on several factors, but all aerosol products have a propellant, a solvent, and a liquid active ingredient which differs depending on the final product type.
- Valve opening shape: The valve's shape and size can determine if larger or smaller
amounts of mist pass through it.
- Propellant pressure: The propellant pressure relates to how hard the spray is forced
out of the container. Higher pressures create larger particles compared to lower pressure
aerosols. Solvents can help lower this pressure and reduce particle size.
- Propellant-to-product ratio: With more propellant in the container, the propellant's
pressure can be higher.
- Chemicals: Chemistry plays a significant role in how the final result looks and acts.
The chemical makeup of both the active ingredient and propellant is essential.
Foams have a dense structure when pumped out of the aerosol container. Foam goods include shaving cream and mousse. The foaming action stretches the number of uses of active ingredient in the container. Additionally, the foam texture is preferred by some consumers for its ease of use and even application. Some chemicals used in foam sprays include:
- Ethanolamines: Ethanolamines have a variety of forms. Some of these are used in foaming bath soap and in shaving cream.
- Ammonium Hydroxide: Ammonium hydroxide is a gaseous component of many cleaning products, but it also is used in shaving cream, tire inflators, puncture seal products, and seam fillers. The density of the ammonium hydroxide is inversely related to the concentration of ammonia.
Air is a critical component of aerosol products, and different propellants require various headspace minimums in the container. Filling the can too much could increase the pressure inside to dangerous levels.
- Hydrocarbons: Goods with this propellant requires at least five percent headspace.
- Fluorocarbons: Though no longer in use, fluorocarbons needed a minimum of five percent headspace.
- Carbon Dioxide (CO2): The amount of CO2 in the product increases the liquid product by one cubic centimeter for every one gram of CO2. The maximum amount of headspace you should have is 15 percent. Ideally, the headspace should take up 15 percent of the total volume.
- Nitrogen (N2): Nitrogen has the highest space requirement of these four common propellants. This propellant's optimum headspace is 45 percent of the container's volume.
The solvent is like a chemical bridge. It allows the liquid product to create a solution with the propellant. Thanks to the thorough, even mixture made by the solvent, the product will last longer without the ingredients separating.
Solvents can also affect the size of the particles that come out of the aerosol can. If the propellant pressure is too high, the particles could come out too large. For inhalers, which require the particles to be small enough to reach the inner portions of the lungs, a mistake of the wrong sized particles could be dire. Solvents can cut down on the pressure of the propellant, ensuring the sprays stay at their required particle size.
The final use for solvents is to provide particular properties to the active ingredients in the aerosol can. For instance, some solvents may slow down or speed up the drying time for spray paint, depending on what is desired. Glycol ethers are a common solvent used for some applications.
Space sprays have the finest mist. The particles from these containers measure less than 50 microns, making this fine spray ideal for delivering inhaled medications. Most space sprays are household air fresheners, medical inhalers, and some insecticides. These products require the sprayed portion to remain in the air rather than wetting a surface. Although the particles are small, the liquid product inside is still vital to performance.
Surface coats have more massive particles, up to 200 microns. The spray from surface coat aerosol containers often feels wet due to the larger particles. Cleaning products, spray paints, and personal care goods often fall into the surface coat category. Some chemicals used in these types of aerosols include:
- Glycol ethers: Glycol ethers are a common solvent used for surface applications. Hexyl CELLOSOLVE has a slow drying rate, making it an ideal solvent for use in cleaning products that may need to soak on a surface before drying.
- Frekote: Frekote is a releasing agent that may be packaged in an aerosol can. When applied to a mold surface, it allows the molded item to release easily without damage. When packed in an aerosol container, Frekote has a quick evaporation rate and no CFCs in the container.
- Aliphatic hydrocarbons: Aliphatic hydrocarbons are the main ingredient in many goods that are sprayed, such as insecticides, cleaners, and personal care products.
Considerations to Make When Packaging Aerosols
When packaging aerosols, you'll need to consider several factors that will play into the ingredients used. The answers to these questions will help you choose active ingredients, propellants, and solvents to go into the final aerosol product.
Another variation of this question is what the product must do. Space sprays need to stay in the air for killing air-borne insects or freshening the air. However, cleaning products must remain wet on surfaces to properly disinfect them. The larger particles that allow moisture to come out of the aerosol can with the spray make surface coatings possible. Surface coatings are less likely to be aspirated, making this form a better option for more dangerous substances that could cause severe lung damage if inhaled.
The package design is also essential and determined by how consumers will use the spray. Consumer goods such as shaving cream or shower mousse may benefit from an easy-to-open container that wet hands can grip in the shower.
The final size of the package is also a vital decision to make during the planning phase. Most aerosols are designed to use with one hand, so the container cannot be too large or heavy to prevent the average person from using it. The type of propellant used will also determine how much of the can's volume must remain free for headspace, which will dictate the size of the container and how much active ingredients the container can hold.
The consumer uses for a product are essential but not the only consideration when packaging aerosol goods. Where and when the result reaches the market also should come into play when planning aerosol products.
The target markets have more to do with local restrictions than consumer preferences. Not all countries have the same laws governing which chemicals can be used in aerosol products. If marketing to multiple countries with different regulations, does it make fiscal sense to create different formulations or would it cost less to use the same blend for worldwide sales? How the aerosol is expected to sell in different markets can make this decision easier.
The country and/or location where you will sell is not the only factor when you think about location. Think about which demographics you wish to target and where your chosen consumers live. Does your product need an organic label for marketing in natural stores? Do you need to change your marketing for various parts of the country to target different groups? Perhaps you need different labels to tout various benefits of your product for specific demographics. For instance, maybe you want to market your organic cleaning solution as an all-natural product in a major city at multiple organic food stores. But perhaps you would instead tout the cleaner's toughness to a more rural market with farmers and ranchers.
How short is your timetable? Do you need a speedy response? If time is of the essence, your product customization choices may be limited. Setting a longer timeline for production and shipping could help you create your ideal aerosol product.
Consider if your product will need special labeling for organic materials or approval for food or medical use. Include in your product release schedule the time it takes to do the background paperwork. A single delay in government paperwork could hamper your plans. Add some extra time to your program, especially if you're reliant upon third parties or government agencies to gain approval for producing, marketing, or labeling your product.
Learn more about aerosol products
Aerosols have numerous applications, and the chemicals used in them are just as varied. The ease of use and increasing use of more environmentally-friendly chemicals have helped drive the rise in demand for aerosol products in recent years. You can find out more about our aerosol offerings by contacting us at Brenntag. We can connect you with the chemicals you need.
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