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Resin identification code

Resin identification code is a chemistry topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Resin identification code rather than just read about it. In short: A resin identification code (RIC) is a symbol embedded on plastic products, used to sort plastic waste for recycling. They consist of an equilateral triangle with a number inside indicating the product's resin content.

Resin identification code — main illustration
Resin identification code — illustration

Key takeaways

  • Resin identification code belongs to chemistry; place it in that map before memorising details.
  • Learn the definition first, then one example that makes the definition concrete.
  • Connect Resin identification code to a quantity you can measure, compute or draw — that is where exam questions come from.
  • Reproduce the core statement of Resin identification code from memory before moving on to harder problems.

Reference excerpt

A resin identification code (RIC) is a symbol embedded on plastic products, used to sort plastic waste for recycling. They consist of an equilateral triangle with a number inside indicating the product's resin content. These symbols were created in 1988 by the Plastics Industry Association in the United States, amid growing concerns about plastic pollution. Since 2008, they are administrated by the ASTM and comprise the technical standard D7611/D7611M-26 "Standard Practice for Coding Plastic Manufactured Articles for Resin Identification". The European Commission Decision 97/129/EC "Identification System For Packaging Materials" extends this system with recycling codes for other materials like batteries, paper, and glass. Despite their similarity to the recycling symbol, resin codes do not indicate whether a product is recyclable. They are frequently misinterpreted by consumers, and contribute to wishcycling (the contamination of recycling bins with unrecyclable goods). At the US Environmental Protection Agency's recommendation, a 2013 revision to the ASTM standard replaced the "chasing arrows" with a solid equilateral triangle, but the old symbols are still widely used among manufacturers.

History

The Society of the Plastics Industry (SPI) first introduced the system in 1988 as the "Voluntary Plastic Container Coding System". The SPI stated that one purpose of the original SPI code was to "Provide a consistent national system to facilitate recycling of post-consumer plastics." The system has been adopted by a growing number of communities implementing recycling programs, as a tool to assist in sorting plastics. To deal with the concerns of recyclers across the U.S., the RIC system was designed to make it easier for workers in materials recovery and recycling facilities to sort and separate items according to their resin type. Plastics must be recycled separately, with other like materials, to preserve the value of the recycled material, and enable its reuse in other products after being recycled. When a number is omitted, the arrows arranged in a triangle resemble the universal recycling symbol, a generic indicator of recyclability. Subsequent revisions to the RIC have replaced the arrows with a solid equilateral triangle, to address consumer confusion about the meaning of the RIC, and the fact that the presence of a RIC symbol on an item does not necessarily indicate that it is recyclable any more than its absence means the plastic object is necessarily unrecyclable. In 2008, ASTM International took over the administration of the RIC system and issued ASTM D7611—Standard Practice for Coding Plastic Manufactured Articles for Resin Identification. In 2013, this standard was revised to change the graphic marking symbol of the RIC from the "chasing arrows" of the Recycling Symbol to a solid triangle instead. In the United States and Canada, the Sustainable Packaging Coalition created in 2008 a project called the "How2Recycle" label. The project has expanded to 525 brands utilizing the label in 2023. The How2Recycle label is an effort to remove guesswork out of recycling by instructing consumers how to recycle the packaging of a product and describing which parts can be recycled. The labels also encourage consumers to check with local facilities to see which plastics each municipal recycling facility can accept.

Unicode The different resin identification codes are part of the Unicode block called Miscellaneous Symbols and have the following codes: ♳ (U+2673), ♴ (U+2674), ♵ (U+2675), ♶ (U+2676), ♷ (U+2677), ♸ (U+2678), and ♹ (U+2679). ♺ (U+267A). These emoji were added as a part of Unicode version 3.2 in 2002.

Criticism

In the United States, use of the RIC in the coding of plastics has led to consumer confusion about which plastic products are accepted for recycling. When many plastics recycling programs were first being implemented in communities across the United States, only plastics with RICs "1" and "2" (polyethylene terephthalate and high-density polyethylene, respectively) were accepted. The list of acceptable plastic items has grown since then. Some communities also instruct residents to consider the form of packaging (i.e. bottles, tubs, lids, etc.) when determining what to include in a curbside recycling bin, rather than relying on the RIC. To further alleviate consumer confusion, the American Chemistry Council launched the "Recycling Terms & Tools" program to promote standardized language that can be used to educate consumers about how to recycle plastic products. Although it can be technically possible to recycle a particular type of plastic, it is often not economically feasible to do so, and that can mislead consumers into thinking that more plastic is recycled than really is. In the U.S., it was estimated only 8.5% of plastic waste was recycled in 2018.

See also List of symbols Recycling codes Plastic recycling Thermoplastic—softens with heat Thermosetting polymer—does not soften with heat

References

External links

Official website Official website (SPI) at the Wayback Machine (archived 2002-04-21)

Worked examples

Example 1 — a first encounter with Resin identification code

Start with the simplest possible case. Write down what Resin identification code claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In chemistry, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Resin identification code before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Resin identification code ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Resin identification code

In research
Resin identification code appears in chemistry research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry
Engineering practice reuses Resin identification code in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom
Resin identification code is common in secondary-school and first-year university syllabi. It links to neighbouring topics American inventions, Classification systems, Consumer symbols, so understanding it makes those chapters shorter.
In everyday life
Look for Resin identification code outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Resin identification code in 20 minutes

  1. Read the reference excerpt below once, without taking notes.
  2. Close the page and write down what Resin identification code means in your own words.
  3. Compare your version with the excerpt and mark what you missed.
  4. Work through the three examples above with pen and paper.
  5. Explain Resin identification code out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Resin identification code in simple terms?

A resin identification code (RIC) is a symbol embedded on plastic products, used to sort plastic waste for recycling. They consist of an equilateral triangle with a number inside indicating the product's resin content.

Why does Resin identification code matter?

Because it connects several chemistry ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Resin identification code?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Resin identification code.

Tags

  • American inventions
  • Classification systems
  • Consumer symbols
  • Encodings
  • Plastic recycling
  • Polymers

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