- 1 What makes plastic different from its alternatives
- 2 Thermoplastics and thermosetting plastics
- 3 Plastic packaging for food
- 4 Types of plastic food packaging
- 5 Safety and plastic food packaging
- 6 Plastic is the most commonly used food packaging material.
Have you noticed whether it is takeout or you’re buying food from the grocery store, your food will always be packed in plastic packaging? Have you ever wondered why food, for the most part, comes in plastic packaging? This article explores the reason behind these very questions.
It looks into facts and figures as to why different plastics are used to contain different kinds of foods and what differs plastic from the alternatives currently present.
About 40 percent of the global plastic production goes into the packaging industry.
It is used all over the world to package goods with Europe packaging over 50 percent of its food in plastic.
But the point in question is why there is excessive usage of this particular material when alternatives such as glass, metal, silicone exist.
To understand this, we have to know the nature of the material in question- plastic.
What makes plastic different from its alternatives
Plastic is a compound that results from processing fossil fuels such as coal, oil, natural gas.
Polyethylene, introduced in 1933, is the most commonly used type of plastic.
Before the introduction of plastic to the world, glass and other materials such as wood were used in its place.
Each one of these alternatives had shortcomings of their own, with glass being too brittle and was easy to break.
It also added to the weight of the good, which made transportation of goods from one place to another harder.
There was a breakthrough in the packaging industry with the introduction of plastic.
Plastic is a versatile compound.
It is lightweight and does not add unnecessary additional weight to the weight of the good it contains.
It is moldable and has elastic properties, thus can be made into different structures and shapes following the requirement of the good it is holding.
The versatility in the appearance and function of plastic makes it an ideal packaging material.
It is not very reactive.
It does not react with most acids, and alkalis.
However, depending on its type, it may absorb the contents of its holding.
It provides a wide range of options from which you can choose.
It offers different heat resistance options.
Different barrier control options are available depending on the type of plastic.
It can also be dyed to make the material available in different colors.
It, however, is not perfect and has a few issues of its own.
It is not always impermeable, and this property can vary with the type of plastic.
Thermoplastics and thermosetting plastics
The properties of plastic vary with their type.
Have you noticed the plastic packaging of cosmetics and pharmaceutical products is different, in every respect, from the plastic packaging of containers holding say, milk?
This is because different products require different packaging properties.
Thermosetting plastics are used for packaging toiletries and cosmetics because this type of plastic can only be molded once by heating.
This plastic packaging is single use only and requires to be either disposed of or recycled after use.
The heat will damage this type of packaging.
Thermoplastics are the kind of plastics that can be molded more than once by melting and reheating them.
These plastics are used to make containers.
These containers do not necessarily require to be disposed of.
They can be refilled or recycled.
Plastic packaging for food
Almost all kinds of foods are packaged in plastic despite having different physical and chemical properties.
Other than providing a wide range of appearance forms such as being transparent or translucent, plastics also prevent the growth of bacteria and microorganisms by not providing them a suitable environment in which they can thrive.
This particular property is of great importance because foods need to be well-protected against agents that may cause spoilage.
Plastics are inert and do not interact with most organic and inorganic materials.
Most plastics are impermeable, but their permeability varies with the change in density of the components of the plastic.
They also, depending on the type of plastic, do not break easily, offering apt protection to the packaged food.
Plastics exist in different forms for different packaging purposes.
They may exist as elastic films.
The flexibility of such plastics aids in the packaging of liquids such as milk and oil.
Materials as such have a short shelf life hence packaging them in flexible plastic bags is the way to go.
Plastic containers that are hard and rigid aid in holding foods that have a relatively long shelf life and require extra protection from external heat and pressure — these help in providing sufficient protection and insulation so that the foods last longer without spoiling.
The usage of plastic in cartons is also of great importance as it aids in the transportation of foods in bulk.
They combine with cardboards providing sustainability.
Plastic is printable and can be colored, thus making it the ideal packaging material.
It can be transparent, translucent, or can be dyed as per the needs of the packaging.
Types of plastic food packaging
Polyethylene is a thermoplastic.
It is the most commonly used type of plastic.
It is an excellent insulator and does not conduct electricity.
Polyethylene, being a thermoplastic, melts on heating instead of burning.
They thus do not degrade to a significant degree.
They can be melted by heat and can be cooled to make them into different shapes to serve a different purpose.
Examples of polyethylene include plastic bags and such.
It is because they are thermoplastics that they melt instead of burning when heated.
They are not very resistant to oils and fats and are not entirely impermeable to gases.
The properties vary with the change in the density of polyethylene.
The more the crystalline it is, the higher the density and vice versa.
Based on the density of polyethylene, it can be categorized into High-density Polyethylene (HDPE) and Low-density polyethylene (LDPE).
LDPE is short for low-density polyethylene.
It has a low density and is very flexible.
This property allows for it to stretch when strain is applied to it.
LDPE is used to make packaging materials such as plastic bags.
They don’t offer impermeability and have a lower melting point which falls around 110 degree Celsius.
They thus have a lower resistance to heat and are not suitable for protection against higher temperatures.
Examples of Low-density polyethylene are plastic bags for frozen foods, flexible plastic bottles.
HDPE is short for high-density polyethylene.
It has a high density, and due to its crystalline structure are harder.
They are not very flexible and provide excellent resistance to gases and solvents.
They are impermeable have melting points higher than LDPEs.
They are rigid and are the most robust grade of polyethylenes.
Examples of High-density polyethylenes include milk boxes, juice boxes.
Polyethylene terephthalate (PETE)
PET or PETE is a form of thermoplastic that is hundred percent recyclable.
They have relatively high resistance.
They are resistant to water.
It has excellent strength and is lightweight, making it suitable to carry materials.
It can either be transparent or dyed to different colors.
Allowing buyers to see the contents through the packaging.
Their recyclability makes PETE sustainable.
Examples of PET include disposable water bottles.
Polyvinyl chloride (PVC)
This thermoplastic exists in both rigid and flexible forms.
It is sturdy and has excellent resistant properties.
It acts as an excellent insulator.
It is chemically inert to inorganic solvents.
It is a hundred percent recyclable making PVCs sustainable.
Examples of PVCs include packagings that have pockets such as that used for bubble gums and tablets and capsules.
This thermoplastic is inert chemically with a melting point of around 160 degree Celsius.
It is resistant to chemicals that are commonly found.
They are resistant to water vapors and other solvents.
They offer excellent resistance to heat and is used for packaging materials that require heating in the microwave afterward.
This plastic is malleable.
It is highly elastic, and when it is heated past its transition temperature, it softens.
It is sturdy and exists in a solid state at a normal temperature.
When it is heated past its transition temperature, it softens and can be easily molded into a different shape or form.
It is highly flammable and can dissolve in some organic solvents.
However, it does not react with most substances.
Examples of PS include disposable plates and cups.
Safety and plastic food packaging
Plastics have been given identification codes which help identify what plastics are safe to package food.
Each type of plastic has a code of its own approved by the Food and Drug Administration in the US.
This identification code is also known as the resin identification code.
The commonly used food plastic packagings are given codes one through seven.
This identification code is its recycling number.
These codes are engraved on the sides of the bottles and are collected based on this code, to recycle.
Following are the resin identification codes that are given to different types of plastics:
- Resin identification code 1 – Polyethylene terephthalate
- Resin identification code 2- High-density polyethylene
- Resin identification code 3- Polyvinyl Chloride
- Resin identification code 4- Low-density polyethylene
- Resin identification code 5- Polypropylene
- Resin identification code 6- Polystyrene
- Resin identification code 7- Other (plastics other than the plastics given identification codes 1 through 6)
Out of these resin identification codes, Polyethylene terephthalate (Recycling number 1), High-density polyethylene (Recycling number 2), Low-density polyethylene (Recycling number 4) and Polypropylene (Recycling code 5) have been marked safe to use for food packaging.
There are no health risks or hazards that have been studied to be associated with the usage of these plastics for food packaging.
Polyvinyl Chloride (PVC) with recycling code #3, has been noted to contain phthalates.
PVCs are not very rigid thus to increase their rigidity BPA is added into them.
BPA is known to cause problems in humans where the elements of BPA mimic the hormones naturally present in the human body and lead to disorders such as cancers.
Polystyrene (PS) with recycling code #6 contains benzene and styrene.
These are known to have carcinogenic properties.
When exposed to hot foods, the Styrofoam can release toxic chemicals which on consumption can cause the absorption of these toxins in our system.
Other plastics with recycling code #7 include plastics such as Polycarbonate (PC).
Polycarbonate is a derivative of Bisphenol-A which is a known carcinogenic and can cause hormonal disruptions, making it unsafe for packaging food.
Plastic is the most commonly used food packaging material.
We can no longer do without plastic.
We rely on plastics for everything; from packaging foods to carrying goods from one place to another.
Our reliance on plastic, in recent years, has increased to such an extent that it has replaced every other material that was being used before the introduction of plastic.
Glass, wood, cloth-based materials have ceased to exist- more so in the packaging industry.
There is no denying the usefulness of plastic.
Plastic food packaging is thus safe, and there are no health concerns attached to it except for those that have been marked unsafe.
Plastics are of great benefit because they are light-weight, and though they are not biodegradable if appropriately recycled, they can save energy and ultimately reduce the food that is wasted.
So if you were confused about using plastic for food packaging because you had concerns relating to health risks associated with the use of plastic, don’t be because findings show except for a few types, the rest are absolutely safe for use.