Plastics are present in almost every aspect of daily life - from food packaging to electronic equipment to interior and vehicle components. Due to the variety of polymeric materials and their properties, a coding system has been introduced to help identify the different types of plastics. Where are they located and what do they mean?
Marking system and its basic types
The international plastics labeling system is based on codes consisting of digits from 1 to 7, placed inside a triangle formed by three arrows - the recycling symbol. Each digit corresponds to a specific type of plastic. Which one? Here's our quick guide!
1. PET (polyethylene terephthalate)
- Mainly used for beverage bottles and food containers.
- It features good gas barrier properties, transparency and low weight.
2. HDPE (high density polyethylene)
- Used in packaging for household chemicals, cosmetics and milk bottles.
- Chemically and mechanically resistant, great for recycling.
3. PVC (polyvinyl chloride)
- It is used for pipes, building profiles, cable insulation and packaging for non-food products.
- Very durable, weather resistant, but more difficult to recycle.
4. LDPE (low density polyethylene)
- Used in the production of films, plastic bags and flexible packaging.
- It is characterized by high flexibility and water resistance.
5. PP (polypropylene)
- It is used in food containers, automotive parts and medical devices.
- Heat and chemical resistant, often used in microwaves.
6. PS (polystyrene)
- Used for disposable packaging, building insulation and electronics components.
- Known for its fragility and low resistance to mechanical damage.
7. OTHER or O (Other plastics)
- Includes biodegradable polymers, polycarbonates, acrylics and polymer blends.
- Often used in specialized products, such as reusable bottles, medical equipment components and electronics.
Each of these labels helps to identify plastics, recycle them properly and make informed product choices, which is crucial for environmental protection.
Location of markings - where to find the plastic code?
Plastic markings are usually placed on the bottom of the product or in less visible places, such as the inside of the container, the bottom edge of the package or the inside of the lid. In the case of food packaging, the identification symbol can usually be found on the bottom of the container, which helps maintain the aesthetics of the product. On home furnishings or electronic equipment, the markings are often embossed or printed in places that are not visible during normal use, such as the bottom of the device or the inside of the case.
Importance for producers - ecology and economics
For manufacturers, the key is to find a balance between durability, cost and recyclability. The choice of the right material depends on the product's intended use, but given the increasing regulation of plastic waste, it makes sense to bet on highly recyclable materials. If eco-friendliness and closed-loop circulation are priorities, the best choices are HDPE (2), which is the most valuable in terms of recycling, and PP (5), which features durability, resilience and recyclability.
For products where transparency and lightness are key, a suitable material is PET (1), which is easy to recycle but requires quality control for reuse. In contrast, plastics to avoid in the future are PVC (3), which is difficult to recycle and contains harmful additives, and PS (6), which has poor recyclability and often ends up as non-reusable waste.
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