Plastic Recycling Numbers 1-7 Ranked: Microplastic & Chemical Safety

MicroPlastics Research DeskEditorial team

April 23, 2026

10 min read

Last reviewed: May 25, 2026 by the MicroPlastics Research Desk. Submit a correction or see our editorial standards.

Quick Answer

From safest to most concerning for food and beverage contact: #2 HDPE, #4 LDPE, and #5 PPare the least likely to leach harmful chemicals; #1 PET is common but degrades with heat and reuse; #7 (Other), #3 PVC, and #6 polystyrene are the most concerning. All plastics shed microplastics (none are truly “safe”) so the safety ranking is relative, not absolute. For true microplastic avoidance, choose glass, stainless steel, or ceramic for food contact.

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Plastic recycling numbers 1 through 7 ranked by safety

Key Takeaways

The recycling number (1-7) is not a safety rating, it's a resin identification code for sorting.
Safer for food: #2 HDPE, #4 LDPE, #5 PP.
Acceptable but degrades with heat: #1 PET (single-use only, never refill or reheat).
Avoid for food: #3 PVC, #6 polystyrene (styrofoam), #7 (Other, often polycarbonate / BPA).
Even the “safest” plastics shed microplastics with heat, UV, acidity, and physical wear. Glass and stainless steel are the only zero-microplastic options.

The full ranking

Plastic recycling numbers 1-7, safety ranked for food/beverage contact
Safety rank	#	Resin	Common products	Main concern
1 (safest)	#5	Polypropylene (PP)	Yogurt cups, takeout containers, straws, bottle caps	Lowest leaching of common plastics. Some particle shedding under microwave heat.
2	#2	High-density polyethylene (HDPE)	Milk jugs, juice bottles, detergent bottles	Considered low-risk; does shed micro/nanoplastic with UV exposure.
3	#4	Low-density polyethylene (LDPE)	Plastic bags, cling wrap, squeeze bottles	Low chemical leaching; sheds fibres in food contact and laundry.
4	#1	Polyethylene terephthalate (PET, PETE)	Water bottles, soda bottles	Antimony leaching under heat; major microplastic source when reused or warmed.
5 (avoid where possible)	#7	Other (mixed; often polycarbonate, BPA, BPS)	Reusable water bottles (older), 5-gal water jugs	Often contains BPA or replacement bisphenols (BPS, BPF), known endocrine disruptors.
6 (avoid)	#3	Polyvinyl chloride (PVC)	Cling wrap, food packaging films, pipes	Releases phthalates and vinyl chloride. PVC microplastics implicated in NEJM 2024 cardiovascular study.
7 (avoid)	#6	Polystyrene (PS, Styrofoam)	Takeout containers, cups, meat trays	Releases styrene (IARC possible human carcinogen). High particle shedding under heat or contact with hot/oily food.

Why the recycling symbol doesn't mean what you think

The triangle of arrows with a number inside is a Resin Identification Code (RIC), introduced by the plastics industry in 1988 to help sorters at recycling facilities. It is not a safety rating, an indicator of recyclability in your community, or a guarantee that the item was made from recycled material.

In practice, only #1 PET and #2 HDPE are widely recycled in most US and EU municipal programs. #3-#7 are rarely accepted at curbside recycling regardless of the symbol.

Each plastic explained

#1 PET / PETE. Polyethylene terephthalate

The most common single-use food and beverage plastic. Considered food-safe for single use but problematic when reused or exposed to heat. PET releases antimony trioxide (a manufacturing catalyst) at elevated temperatures, and is the dominant material in the 2024 Columbia/Rutgers nanoplastic study of bottled water (240,000 particles/L).

#2 HDPE. High-density polyethylene

Stiff, opaque plastic used for milk jugs, juice bottles, and detergent bottles. One of the lower-leaching food plastics. Still degrades over years of UV exposure and sheds microplastic from wear.

#3 PVC. Polyvinyl chloride

Avoid for food contact. PVC requires phthalate plasticisers to be flexible, and these plasticisers are known endocrine disruptors that leach into food, especially fatty or hot food. PVC was also detected in 12% of carotid plaque samples in the NEJM 2024 cardiovascular study.

#4 LDPE. Low-density polyethylene

Soft, flexible plastic used for shopping bags, bread bags, and cling film. Low chemical leaching, but a major contributor to microfibre and microparticle shedding into food and into the environment.

#5 PP. Polypropylene

Generally considered the safest of the common food plastics. Heat-tolerant (microwave-rated for many products) and chemically stable. Stillsheds microplastics when microwaved, a 2023 University of Nebraska study found a single PP container could release millions of particles per microwave cycle.

#6 PS. Polystyrene

Avoid for food contact. PS releases styrene under heat or oily food contact; the International Agency for Research on Cancer classifies styrene as a possible human carcinogen (Group 2A as of 2019). Expanded polystyrene (Styrofoam) is especially friable and sheds particles readily.

#7. Other (often polycarbonate)

A catch-all category. Older #7 items, especially 5-gallon water cooler jugs and some reusable bottles, are polycarbonate, made with bisphenol A (BPA), a known endocrine disruptor. “BPA-free” alternatives often use BPS or BPF, which have shown similar hormonal activity. See our BPA-free guide for the full picture.

Quick rules of thumb

Never microwave anything in plastic, even #5.
Never put hot food or liquid into #6 polystyrene.
Don't reuse #1 PET water bottles.
Avoid #3 PVC and #7 polycarbonate for food contact entirely.
For food storage, glass or stainless steel beats every plastic.

For full reduction strategies see microplastics in plastic containers and worst microplastic ingredients.

What the MicroPlastics app checks

Material, stainless, glass, ceramic, cast iron, plastic (PE / PP / PS / PVC), silicone, wood.
Visible condition, scratches, chips, warping, fade.
Brand and product line, flags for non-stick / PFAS-treated items.
Use-context flags you log, heat exposure, dishwasher cycles, contact with hot or fatty food.
Cited published research behind the 0–100 risk score.

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Frequently Asked Questions

What plastic numbers are safest for food?

Plastics #2 (HDPE), #4 (LDPE), and #5 (PP) are considered the safer common food-contact plastics, with the lowest documented chemical leaching. #1 PET is acceptable for single use only. All plastics shed microplastics under heat, acidity, or wear.

Which plastic numbers should you avoid?

Avoid #3 (PVC) for food because of phthalate leaching, #6 (polystyrene) for hot or oily food because of styrene release, and #7 (Other) when the item may contain polycarbonate or BPA. PVC was also linked to cardiovascular events in the 2024 NEJM study.

Is plastic #5 safe to microwave?

Polypropylene #5 is the most heat-stable common food plastic and is often labeled microwave-safe. However a 2023 University of Nebraska study found a single PP container can release millions of microplastic particles into food per microwave cycle. Glass is safer.

Is plastic #1 PET safe for water bottles?

PET is FDA-approved for single use but is the dominant material in the 2024 nanoplastic study of bottled water (240,000 particles per liter). It is not designed for reuse, refilling, or heating. Glass or stainless steel is safer for repeated use.

What does the recycling number actually mean?

The number inside the recycling triangle is a Resin Identification Code (RIC), introduced in 1988 to help sorters at recycling facilities identify the polymer. It is not a safety rating and does not guarantee an item is recyclable in your community.

Sources

ASTM International (2013). D7611 Standard Practice for Coding Plastic Manufactured Articles for Resin Identification. ASTM.
Hussain KA, Romanova S, Okur I, et al. (2023). Assessing the release of microplastics and nanoplastics from plastic containers and reusable food pouches: implications for human health. Environmental Science & Technology.
Marfella R, Prattichizzo F, Sardu C, et al. (2024). Microplastics and nanoplastics in atheromas and cardiovascular events. New England Journal of Medicine.
IARC Working Group (2019). Styrene, Styrene-7,8-oxide, and Quinoline (IARC Monograph 121). International Agency for Research on Cancer.

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