There is a lot of misinformation concerning the toxicity of plastics and it’s important to note that this is a complex issue. The very nature of plastics means there are toxicity impacts associated with their manufacture, use and disposal, but that doesn’t necessarily mean all plastics represent a risk to your personal health or that of the environment.
The key issue to understand is the circumstances where plastic is likely to release toxic chemicals and where the wrong type of plastic is selected for a particular application. For example, PET (polyethylene terephthalate) most commonly used in plastic drink bottles, is generally known as one of the so called ‘safe plastics’, but PET packaging contains the chemical antimony which Australia’s National Pollutant Inventory describes as “toxic properties similar to that of arsenic”. Under normal circumstances the amount of antimony that could be released from PET packaging is very low but when heated via a microwave or in your dishwasher, antimony and other chemicals are released (which is why PET is unsuitable for re-use as food or beverage packaging).
Over and above toxicity issues with particular polymers there are two further issues:
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Additives
Base polymers often have a range of other chemicals added to them – softeners, flame retardants antioxidants and anti-bacterial agents to achieve properties desired for the final product. Many of these additives increase the toxicity of the plastic itself for example, a brominated flame retardant is applied to nearly all synthetic textiles used in clothing, soft furnishings and mattresses.
Brominated chemicals are under increasing criticism for their use in household furnishings and where children would come into contact with them. Many believe that Polybrominated Diphenyl Ethers (PBDE) could have harmful effects on humans and animals. Increasing concern has prompted a number of European countries to ban some of them, following the precautionary principle more commonly applied in Europe. PBDEs are known to be lipophilic and bioaccumulative and testing has identified PBDEs in people all over the world.
Some brominated flame retardants were identified as persistent, bioaccumulative, and toxic to both humans and the environment and were suspected of causing neurobehavioral effects and endocrine disruption. One particular target group is firefighters who are exposed to brominated fire retardants during firefighting operations and are suffering cancer rates that far exceed the general public. With very low recycling rates and the high volumes of plastic entering our oceans there is little question that brominated flame retardants are being released into the environment.
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Sorption of other pollutants in marine environments
Plastics are a particular threat because of their ability to absorb toxins and other contaminants. Studies have shown that plastic found in our oceans (particularly microplastics) suck up so many dangerous Persistent Organic Pollutants like the banned insecticide DDT and polychlorinated biphenyl (PCBs) that they were found to be up to 1 million times more toxic than the ocean surrounding them.
Ironically, many of the plastic polymers considered to have low toxicity effects have a much higher sorption rate (e.g. HDPE and LDPE) and consequently when found in the marine environment are as toxic as other polymers.
As a broad guide the following graphic is a quick summary of the various plastic labels and their “toxic threat” levels.
1. Polyethylene Terephthalate
PET or PETE stands for polyethylene terephthalate, a plastic resin and a form of polyester.
Where is PET found?
PETE is commonly used in:
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soft drink and water bottles
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cosmetics
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household cleaners
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juice
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salad dressings
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oil
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condiments and sauce containers
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synthetic (polyester) clothing
Health Concerns
Studies have found levels of antimony (a toxic chemical) leaching from water bottles that have been placed in heat for a prolonged time. Although PETE does not contain BPA or phthalates, it’s always best to make sure that your water bottles are not temperature abused. PETE plastic should not be reused because cleaning detergents and high temperatures can cause chemicals to leach out of the plastic. NB:Plastic #1 is only intended for a one time use.
2. High-Density Polyethylene
High-density polyethylene (HDPE) is a polyethylene thermoplastic made from petroleum. HDPE is hard, opaque and can withstand somewhat high temperatures.
Where is HDPE found?
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plastic toys
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outdoor furniture
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milk bottles
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heavier weight plastic bags like those used in departments and fashion stores
Health Concerns
No known health concerns.
3. Polyvinyl Chloride
Polyvinyl chloride (PVC) is a thermoplastic polymer. Through the use of phthalates, a plasticizer, it can be made softer and more flexible. Read about the harm of phthalates here.
Where is PVC found?
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cordial bottles
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building materials (vinyl flooring and bench tops, PVC pipe)
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car interiors
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cling wrap
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pool toys and other inflatable structures
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clothing (vinyl)
Health Concerns
PVC is one of the toxic plastics that should be avoided. Helpful measures include:
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purchase a shower curtain made from organic hemp, bamboo or PEVA. PEVA (polyethylene vinyl acetate) is a non-vinyl (PVC-free), chlorine-free, biodegradable plastic
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air the car before getting into it
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avoid using cling wrap made with PVC
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avoid inflatable structures, air mattresses, and toys made with PVC. Choose all baby toys, pool toys, and bath toys that are labelled to be PVC, phthalate and BPA free
4. Low-density polyethylene
Low-density polyethylene (LDPE) is a thermoplastic made from petroleum. It can be translucent or opaque. It is flexible and tough but breakable.
Where is LDPE found?
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aseptic packaging and liquid paperboard cartons e.g. juice and milk cartons (as the waterproof inner and outer layer)
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most single use plastic grocery bags
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some packaging material
Health Concerns
No known health concerns.
5. Polypropylene
Polypropylene (PP) is a thermoplastic polymer. It is strong, tough, has a high resistance to heat and acts as a barrier to moisture.
In 2008, researchers in Canada asserted that quaternary ammonium biocides and oleamide were leaking out of certain polypropylene laboratory equipment, affecting experimental results. Polypropylene is used in a wide number of food containers such as those for yogurt.
Where is Polypropylene found?
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synthetic ropes and nets
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yogurt & margarine tubs
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plastic cups & baby bottles
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kitchenware, microwavable plastic containers and lids
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plastic Tubing
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plant Pots
Health Concerns
Most PP is labelled as microwavable safe and dishwasher safe - however, please note microwavable/dishwasher safe only means that the plastic will not warp when heated. It does not imply that it is a healthy practice.
6. Polystyrene
Polystyrene (PS) is a petroleum-based plastic. It can either be hard or used in the form of styrofoam.
Polystyrene is commonly used in containers for food and drinks. The styrene monomer (from which polystyrene is made) is a suspected cancer agent. Styrene oligomers in polystyrene containers used for food packaging have been found to migrate into the food. There are concerns that when heated polystyrene food packaging may release styrene and other chemicals. Some sources suggest that packaging of such foods containing carotene (Vitamin A) or cooking oils must be avoided.
Where is Polystyrene found?
Polystyrene is widely used in packaging materials and insulation. Some common items include:
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disposable cutlery
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clam Shells (foam packaging used by restaurants and cafes for hot food takeaway containers
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CD and DVD cases
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foam cups (juice, milkshakes etc).
Health Concerns
According to the Foundation for Achievements in Science and Education fact sheet, long term exposure to small quantities of styrene can cause neurotoxic (fatigue, nervousness, difficulty sleeping), hematological (low platelet and haemoglobin values), cytogenetic (chromosomal and lymphatic abnormalities), and carcinogenic effects. Styrene is classified as a possible human carcinogen by the US EPA and by the International Agency for Research on Cancer.
7. Other plastics (varies)
Plastic #7 can be a little tricky as it stands for “Other” and covers a wide range of plastics including Other Plastics, such as acrylic, nylon, polycarbonate, and polylactic acid (a bioplastic), and multilayer combinations of different plastics- which may or may not contain harmful chemicals like BPA.
Polycarbonate is derived from BPA. Read more about the harm of BPA here.
Where is Polycarbonate found?
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electrical wiring
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CD/DVD cases
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baby bottles
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3 and 5 gallon reusable bottles
Health Concerns
BPA has been found to be an endocrine disruptor. Choose bottles made with the #1, #2, #4, or #5 recycling codes.
Author: Dave West