What types of plastic bottles are safe to use? (7 classes of plastics) 

In this article, it shall be discussed what type of plastic bottles are safe to use and consume. Other topics that will be covered are: 

  • What is plastic?
  • What are polymers?
  • What are the types of plastic?
  • What are the impacts of plastic on health and the environment?
  • FAQs

What types of plastic bottles are safe to use?

Plastic bottles made from type 1 plastic (PET which expands to polyethylene terephthalate) can be opted for because there are no reported medical risks provided PET is not exposed to heat. 

Plastic bottles made from Polypropylene, High-density polyethylene and low density polyethylene can also opt. 

However, these materials are synthetic and hence, non-biodegradable. They may cause harm to the environment and humans too in the long run. 

From an environmental perspective, plastic bottles made from bioplastics (that are made from sugarcane or cornstarch) can be opted for because they are generally regarded as non-toxic and biodegradable.

What is plastic?

In simple terms, plastic is a polymer which is made from repeating units (monomers) and these monomers are linked with chemical bonds. 

Plastic is found everywhere these days. From the packaging material to plastic bottles to furniture items, and decoration material. Chances are that plastic is present in the majority of the stuff that you own. 

The use of plastics was not this great and eminent from the start. This use gained momentum after the industrialisation era when various episodes happened like fervent commercialism and rapid urbanisation. 

The features and utilities that plastic offered appeared to be unmatched and as a result, it became a necessity rather than just a luxury. Every industry these days is associated with the use of plastic be it construction, medicinal, packaging, pharmaceutical, or food industry. 

Plastic has dominated every sector and every aspect.

However, it is not all glittery when it comes to the use of plastic. With the development and advancement of science and environmental studies, it was excavated that what was thought to be an angel was actually the devil.

It was studied that although plastic had a great utilitarian value while also being cost-efficient, the use of plastic had severe impacts on human health and the environment. These effects will be further detailed in future sections. 

What are polymers?

In order to get a better grasp of what plastic is, it is essential to know the science of polymers. That is because plastics are just another type of polymer.  

The word polymer is supposed to be derived from the Greek language which means many parts. Polymers are made up of small repeating units. These small repeating units are termed monomers. Monomers are held together by chemical bonds.

Polymers can be classified into two groups. These may be:

  • Natural polymers 
  • Synthetic polymers

As the names suggest, natural polymers are found in nature. There is no need to synthesise them in any way. Whereas, synthetic polymers, on the other hand, are synthesised in the lab.

Natural polymers are those polymers found in nature. It can be said that nature is the scientist that made these polymers and quite a magnificent one. Examples of these polymers can be: 

  • DNA
  • Protein
  • Cellulose
  • Silk
  • Wool
  • Carbohydrates
  • Chiton

These natural polymers adhere to nature’s ways and thus pose no great threats to nature and the environment. However, there are some factors that may change this proclivity. 

As per synthetic polymers, these polymers are synthesised in the lab. These synthetic polymers are created by man and the rule of thumb is that most of them do not really adhere to nature’s ways. Examples of these polymers may be: 

  • PVC
  • Polyethylene
  • Polyester
  • Epoxy
  • Teflon
  • Dyneema
  • Nylon
  • PET 

What are the 7 types of plastic?

It has been stated and asserted that plastics are found everywhere in the world. Every household contains plastics in the most abundant ways. 

Therefore, it is plausible to assume that there ought to be several types of classification of plastics. Generally, plastics are categorised into 7 classes or types. These may be:

  • PET
  • HDPE
  • PVC
  • LDPE
  • PP
  • Polystyrene 
  • Contemporary plastics 

As it could be guessed that these classes of plastics have several distinct properties and therefore, related functions based on their distinct properties and characteristics. 

The first category of plastics is called PET which expands to polyethylene terephthalate. This type of plastic is usually lucid in colour and is found in disposable beverages, food containers and bottles. Since our subject is plastic bottles, this is the type of plastic we will be getting into more detail about. 

The second category of plastic is called HDPE which expands into high-density polyethylene. It is mostly opaque in appearance and is used widely in juice bottles, detergents, and toiletries containers. This type is considered safe for humans in terms of exposure but it is unsafe for the environment. 

The third category is called PVC which expands to Polyvinyl Chloride. This type of plastic is mostly used in applications such as food wraps, cooking oil bottles and plumbing pipes. PVC contains BPA and phthalates. 

These chemicals are known to cause harm to humans by disrupting hormonal patterns while also being carcinogenic in nature. The constituents of PVC are also quite harmful to the environment as they may leach into the ground and cause toxicity and pollution. 

The fourth plastic category is LDPE, which can be expanded into low-density polyethylene. The common applications of this type of plastic are food warps, grocery bags et cetera. This is relatively safer in the context of HDPE for human health. 

Next in line, we have polypropylene. This type of plastic is termed microwave safe because of its heat resistance properties. Therefore, it is most commonly used in kitchenware. However, even though it is heat resistant. Its use must be limited or else there could be medical complications. 

The sixth type of plastic is polystyrene which is also known as styrofoam. This type of plastic is renowned for packaging materials and disposable containers. However, it is deemed very unsafe to both humans and the environment and its use must be avoided to the best. 

The last category of plastic is called new plastic or contemporary plastic. It included all the new plastics that are synthesised in the market. It may include plastics that contain harmful chemicals like BPA and may also include bioplastics that are both degradable and relatively safer for the environment. 

What are the impacts of plastic on health and the environment?

In the last section, it has been well detailed that there are seven categories of plastics. All these categories pose some sort of harm or threat to humans and the environment. In this section, those effects will be discussed in detail. 

Perhaps, the bluntest issue of any plastic is its ability to not biodegrade. Biodegradability is a natural process in which complex waste is converted into simpler waste by the action of microbes. 

It is nature’s way to ensure that there is no waste left and hence, no waste accumulation. However, synthetic materials like most classes of plastics are not biodegradable because microbes are unable to break them down. 

As a result, they remain in the environment for a very long time. Some studies have found that plastics may remain in the environment for as long as a thousand years. 

But the problem is not just about biodegradability, it is the harmful impacts that are caused when plastics do not biodegrade. Plastics are, by the action of wind or sunlight, converted into microplastics. 

These microplastics are found in every corner of the world. Fish may ingest these microplastics and as a result, they might choke or die. It is estimated that more than 700 species on land have been affected by the presence of plastics in the atmosphere. 

Plastics are made from fossil fuel products. The process and materials involved in the production of plastics result in the emission of greenhouse gases. These gases toxicate the environment and cause global warming. 

Global warming, in turn, then is responsible for a plethora of other side effects as well. Global warming leads to the melting of glaciers, rise in sea levels and unprecedented weather patterns. 

The effects of plastics on human health are also well-known and well-researched. It is studied that plastics cause a number of health complications and anomalies in humans which may include skin diseases or may aggravate to exacerbated issues like cancer and necrosis. 

In a nutshell, the effects of plastics on the environment and human health can be summarised into: 

  • Pollution
  • Global warming
  • GHG emissions
  • Rise in temperature
  • A rise in sea levels
  • Melting glaciers
  • More floods
  • Frequent droughts
  • Unprecedented weather patterns
  • Insects attacks
  • Land degradation
  • Food shortage
  • Food security concerns
  • Species endangerment 
  • Infiltration into the food chains
  • Loss of aquatic life
  • Accumulation of plastics
  • Disruptions of ecosystems

The health complications raised by plastics also include: 

  • Abnormality
  • Reproductive complications
  • Hormonal issues
  • Damage to foetus
  • Necrosis
  • Skin damage
  • Eye allergies
  • Organ defects
  • Cancer
  • Mutation
  • Psychological complication
  • Depression
  • Anxiety
  • Neuro-toxicity
  • Neurological complications 

What types of plastic bottles are safe to use?

It has been stated that most plastic bottles are made from type 1 plastic which is PET. PET is generally considered safe for humans although it is not biodegradable and may be responsible for the leaching of phthalates. 

However, it is not all that glittery. PET, when exposed to heat such as sunlight, may cause various medical complications such as stomach issues, diarrhoea et cetera. Although PET does not contain BPA, many plastic bottles do contain BPA. 

Other decent options can be plastic bottles made from HDPE, LDPE and PP. These options are also relatively safer. 

BPA is responsible for hormonal disruptions and may also cause cancer. Therefore, it is important to avoid bottles that contain BPA. 

Recently, bioplastics have been introduced that are sourced from nature instead of the lab. Bioplastics are made from natural materials like sugarcane, cornstarch, or sugar beets. Since there is no artificiality, chances are that bottles made from bioplastics will not lead to medical complications. 

Another edge that bioplastics have is that they are biodegradable and non-toxic. However, some researchers point out otherwise. While conventional plastics may degrade in hundreds of years, bioplastics may degrade in three years’ time. 


It is concluded that plastic bottles made from type 1 plastic (PET which expands to polyethylene terephthalate) can opt because there are no reported medical risks provided they are not exposed to heat. Plastic bottles made from Polypropylene, High-density polyethylene and low-density polyethylene can also opt. 

However, these materials are synthetic and hence, non-biodegradable. They may cause harm to the environment and humans too in the long run. 

From an environmental perspective, plastic bottles made from bioplastics (that are made from sugarcane or cornstarch) can be opted for because they are generally regarded as non-toxic and biodegradable. 

Frequently Asked Questions: What types of plastic bottles are safe to use?

Can plastic cause cancer?

Yes, plastic may contain various carcinogens and mutagens that may cause cancer, reproductive anomalies and neuro-complications. 

How long does plastic take to degrade?

Plastic may take hundreds of years to degrade. As per research, some plastics may take up to a thousand years to degrade. 


  • Thompson, R. C., Swan, S. H., Moore, C. J., & Vom Saal, F. S. (2009). Our plastic age. Philosophical Transactions of the Royal Society B: Biological Sciences, 364(1526), 1973-1976.
  • Thompson, R. C., Olsen, Y., Mitchell, R. P., Davis, A., Rowland, S. J., John, A. W., … & Russell, A. E. (2004). Lost at sea: where is all the plastic?. Science, 304(5672), 838-838.
  • Wright, S. L., & Kelly, F. J. (2017). Plastic and human health: a micro issue?. Environmental science & technology, 51(12), 6634-6647.
  • Ritchie, H., & Roser, M. (2018). Plastic pollution. Our World in Data.

Leave a Comment