Today’s blog is a review of different types of plastics; their uses and impacts. It also includes actions you can take to reduce plastics use.
PET (Polyethylene terephthalate)
It is a plastic used mainly for bottles of water, drinks or food because it offers a strong barrier to the penetration of oxygen. Over time it tends to release phthalates and therefore the same container cannot be used more than once. It has a density higher than water and therefore, if dispersed in the sea, it can hardly be recovered and disposed of. It has a very low starting viscosity temperature (60-80°C), if you put it in the dishwasher you will find it deformed; to recycle PET it is necessary to bring it to about 280°C. It is easily recyclable and is reused several times.
According to a recent study, water bottles made from PET plastic leach compounds that mimic the hormone oestrogen raising questions about their safety. Previous research has focused on plastics containing the chemical bisphenol-a (BPA). During that time regular PET plastic water bottles have maintained a reputation as safe, at least as far as human health is concerned.
However, lead researcher Martin Wagner says, it’s too soon to say whether drinking out of PET plastic bottles is harmful to human health. It now appears possible that some as-yet unidentified chemicals in these plastics have the potential to interfere with estrogen and other reproductive hormones, just as BPA and phthalates do.
HD-PE (High-density polyethylene)
Polyethylene is one of the most common plastics and the first to be synthesized, it has a high resistance to corrosion and is used to contain food, but also: detergents, shampoos and chemicals. It has a density slightly lower than water, resists well up to temperatures of 120°C and is malleable at 180°C. It is easily recyclable and is reused several times.
HDPE plastic is currently considered a low-hazard plastic with a low risk of leaching. However, HDPE contains nonylphenol which has been found to be dangerous to aquatic life. Nonylphenol is also an endocrine disruptor. This means it may affect your endocrine system, which controls your hormones.
PVC (Polyvinyl chloride)
It is used for pipes, sheeting and insulation-strip curtains (such as used in warehouse coolrooms). It is a rather dangerous type of plastic because it contains many additives including phthalates, which are very dangerous for humans. It’s dangerous for the environment as over time it tends to degrade and pollute the water it comes into contact with because is much heavier than water and if it settles on the bottom of the seas it is difficult to recover it and continues to release toxic substances. The fumes generated by the fusion or combustion of PVC are carcinogenic and also, for this reason, it is not easily recyclable.
LDPE (Low-density polyethylene)
It has long been used for shopping bags, glasses, plates and cutlery. in Europe these products have been banned, replaced by more easily biodegradable plant-derived polymers. It is still used for packaging. The real impact of this type of plastic is its contribution to the of marine life.
It is one of the most popular plastics and is used for a variety of objects. It has excellent mechanical characteristics, withstands high temperatures and fatigue efforts. It softens from 160-170°C and becomes malleable from 190°C. It has a density slightly lower than water, about 0.9g/cm3. It is used for plastic containers, reusable water bottles, medical components, outdoor furniture, toys, luggage and car parts. It is considered the safest of all plastics as it is a robust heat-resistant plastic. Because of its high heat tolerance, it is unlikely to leach even when exposed to warm or hot water. It is approved for use with food and beverage storage. It can be re-used safely and used with hot beverages. However, few studies have reported that it can leach on plastic additives and cause occupational asthma. It is less likely to contain fillers, plasticizers, and additives compared with many other plastics, but they may still be present.
It can be found in solid or foam form and is used especially for food containers and packaging as it is inexpensive and easily synthesized. It is one of the most dangerous plastics as it is not biodegradable and if heated (or worse burned) it emits carcinogenic black fumes; it is often not even accepted by plastic recycling centres. It is the plastic that most pollutes the seas, and it would be appropriate to ban it or severely limit its use.
Polystyrene contains the toxic substances Styrene and Benzene, suspected carcinogens and neurotoxins. Hot foods and liquids actually start a partial breakdown of the Styrofoam, causing some toxins to be absorbed into our bloodstream and tissue.
In this category there are non-recyclable plastics: Polycarbonate (PC), Nylon, ABS etc. some of these are particularly dangerous if not disposed of correctly.
Most microplastic pollution comes from textiles, tyres and city dust which account for over 80% of all microplastic pathogens in the environment.