HDPE vs PET vs PP: How to Choose the Right Plastic for Your Product Packaging

Three resins account for roughly 70% of all plastic packaging on the planet. HDPE, PET, and PP. Pick the wrong one and you're either overpaying for performance you don't need or under-specifying and watching your product degrade on shelf.

The choice isn't complicated once you understand what each resin does well and where it falls apart. Here's the comparison, with actual numbers instead of vague claims.

The Quick Answer

Before the deep dive:

• PET — Clear, rigid, excellent oxygen barrier. Use for beverages, food containers, and anything where clarity and shelf life matter.
• HDPE — Opaque, chemical-resistant, impact-tough. Use for household chemicals, milk jugs, personal care, and anything that needs to survive being dropped.
• PP — Lightest, highest heat resistance, good fatigue resistance. Use for hot-fill food, flip-top closures, and anything going in a microwave or dishwasher.

Now the details.

Physical Properties Side-by-Side

| Property | PET | HDPE | PP | |---|---|---|---| | Resin code | #1 | #2 | #5 | | Density (g/cm³) | 1.33-1.40 | 0.94-0.97 | 0.90-0.91 | | Tensile strength (MPa) | 55-75 | 25-45 | 30-40 | | Max continuous temp (°C) | 70 | 120 | 130 | | Clarity | Excellent | Opaque | Translucent to opaque | | O2 barrier (cc·mil/100in²/day) | 3-6 | 150-200 | 75-150 | | Moisture barrier (g·mil/100in²/day) | 1.5-2.5 | 0.3-0.5 | 0.5-0.7 | | Impact resistance | Moderate | Excellent | Good | | Chemical resistance | Moderate | Excellent | Excellent |

Those numbers tell the story. PET wins on clarity and oxygen barrier. HDPE wins on moisture barrier, chemical resistance, and impact toughness. PP wins on heat resistance and weight.

PET (Polyethylene Terephthalate)

What Makes It Special

Clarity. PET is the only commodity packaging plastic that's optically clear in thick-wall applications. You can see the product through the container. For beverages, condiments, and anything where visual appeal matters at the point of sale, that transparency sells.

PET also has the best oxygen barrier of the three — 25-50x better than HDPE. That's why virtually every carbonated beverage bottle is PET. CO2 stays in. Oxygen stays out. Shelf life is months rather than weeks.

Where It's Used

• Water and soft drink bottles (the big one — billions of units annually)
• Condiment jars and squeeze bottles
• Fresh produce clamshells (thermoformed PET/RPET)
• Peanut butter jars
• Salad dressing bottles
• Personal care packaging where clarity matters

Cost

Virgin PET resin: $0.55-$0.75/lb (Q1 2026, Plastics News). Recycled PET (rPET): $0.65-$0.90/lb. Yes — recycled currently costs more than virgin for most grades because demand for food-grade rPET outstrips supply.

A finished 16 oz PET bottle: $0.08-$0.14 at volume.

Limitations

Heat. PET softens at 70°C (158°F). Standard PET cannot be hot-filled — the bottle deforms. Heat-set PET (crystallized at higher temperatures during production) handles hot-fill up to 85°C but costs 15-20% more.

Stress cracking. PET exposed to certain chemicals (strong bases, some solvents) develops micro-cracks over time. Not suitable for household chemicals.

The rPET paradox: brands want recycled content for sustainability claims, but food-grade rPET supply is tight and priced at a premium. This dynamic flips the usual virgin-vs-recycled cost equation.

Recycling

PET has a 29.1% recycling rate in the U.S. (NAPCOR, 2024). The highest-recycled plastic by rate and by volume. Well-established collection and processing infrastructure. Bottle-to-bottle recycling is commercially proven, though a significant portion of collected PET gets downcycled into fiber (clothing, carpet) rather than back into food packaging.

HDPE (High-Density Polyethylene)

What Makes It Special

Toughness. Drop an HDPE bottle off a loading dock. Pick it up. Keep going. HDPE's impact resistance makes it the default for anything that gets handled roughly — laundry detergent, motor oil, milk, bleach.

Chemical resistance is the other standout. HDPE resists acids, bases, alcohols, and most household chemicals without degradation. PET and PP can't match this across the board.

Moisture barrier is excellent — 3-5x better than PET. For products where moisture ingress causes degradation (powders, supplements, certain chemicals), HDPE outperforms.

Where It's Used

• Milk jugs (the iconic translucent gallon jug)
• Laundry detergent and household chemical bottles
• Shampoo and conditioner bottles
• Motor oil containers
• Pharmaceutical bottles
• HDPE pails (paint, food-grade buckets)
• Grocery bags (HDPE film)

Cost

Virgin HDPE resin: $0.50-$0.68/lb (Q1 2026). The cheapest of the three resins by weight. Recycled HDPE: $0.40-$0.60/lb — one of the few plastics where recycled is actually cheaper than virgin.

A finished 32 oz HDPE bottle: $0.10-$0.18 at volume.

Limitations

Appearance. HDPE is naturally translucent to opaque. You can't see through it. For brands wanting product visibility (juice, condiments, clear cosmetics), HDPE doesn't work.

Oxygen barrier is poor. Products sensitive to oxidation — think oils, certain food products — need an additional barrier layer or a different resin. HDPE bottles for cooking oil are common, but shelf life is shorter than PET alternatives.

Surface hardness is lower than PET. HDPE scratches and scuffs more easily in transit, which can affect shelf presentation for premium products.

Recycling

HDPE recycling rate: 29.3% (EPA, 2024). Similar to PET. HDPE is accepted in virtually all curbside recycling programs. Recycled HDPE has strong secondary markets — lumber alternatives, drainage pipe, non-food bottles. Closed-loop bottle-to-bottle recycling for HDPE is less mature than PET's but growing.

PP (Polypropylene)

What Makes It Special

Heat. PP handles continuous temperatures up to 130°C (266°F) without deformation. That makes it the only option for:

• Hot-fill applications (soups, sauces filled at 85-95°C)
• Microwave-safe containers
• Dishwasher-safe packaging
• Autoclavable medical packaging

PP is also the lightest of the three resins — 30-35% lighter than PET by volume. For a shipping-cost-sensitive product, PP's density advantage reduces freight.

Fatigue resistance sets PP apart from both PET and HDPE. A PP living hinge (the thin flex point on a flip-top cap) survives millions of cycles. PET and HDPE crack after a fraction of that. Every flip-top shampoo cap, every Tic Tac box lid — that's PP.

Where It's Used

• Yogurt cups and dairy containers
• Hot-fill food containers (soup cups, sauce jars)
• Flip-top and snap-cap closures
• Medicine bottles and prescription vials
• Food storage containers (Tupperware, Rubbermaid)
• Microwave-safe trays
• Cosmetics packaging (jars, compacts)

Cost

Virgin PP resin: $0.52-$0.72/lb (Q1 2026). Middle of the pack. Recycled PP: $0.55-$0.80/lb. Like PET, recycled PP often costs more than virgin due to limited supply of food-grade rPP.

A finished 8 oz PP container: $0.06-$0.12 at volume.

Limitations

Clarity is limited. Standard PP is translucent. Clarified PP (with nucleating agents) approaches PET-like transparency but costs 10-15% more and never quite matches PET's glass-like clarity.

Oxygen barrier is moderate — better than HDPE but worse than PET. For oxygen-sensitive products requiring long shelf life, PP alone isn't sufficient.

Cold-temperature brittleness. PP becomes brittle below 0°C. Frozen food packaging in PP can crack during handling. For frozen applications, HDPE or specialized cold-impact PP grades are better.

Recycling

PP recycling rate: approximately 5% in the U.S. (EPA, 2024). The worst of the three by far. The problem isn't technical — PP recycles fine. The problem is collection infrastructure. PP containers come in varied shapes and colors, making automated sorting difficult. Many MRFs still can't efficiently separate PP from the waste stream.

The recycling gap is PP's biggest liability as sustainability regulations tighten. Brands choosing PP should monitor EPR developments closely — the economic cost of non-recyclable packaging is rising fast.

Decision Framework

Choose PET When:

• Product visibility matters (beverages, condiments, clear containers)
• Oxygen barrier is critical (carbonated drinks, shelf-stable food)
• Recyclability is a brand priority (highest public recycling awareness)
• Products don't require hot-filling or microwave heating

Choose HDPE When:

• Chemical resistance is required (cleaners, personal care, chemicals)
• Impact resistance matters (shipping, rough handling)
• Product doesn't need to be visible through the container
• Cost is the primary driver (cheapest resin, cheapest recycled option)
• Moisture barrier is critical (powders, supplements)

Choose PP When:

• Hot-fill processing above 85°C is required
• Microwave or dishwasher use expected
• Living hinges or snap closures are needed
• Weight reduction matters for shipping cost
• Squeeze or flex-back behavior is desired

What About Recycled Content?

California's SB 54 mandates 30% recycled content in plastic packaging by 2028, scaling to 65% by 2032. The EU's PPWR requires 10% contact-sensitive recycled content by 2030 and 50% by 2040.

Supply status by resin (2026):

• rPET: Most mature. Food-grade available but demand exceeds supply. Premium of $0.10-$0.20/lb over virgin.
• rHDPE: Good availability for non-food. Food-grade rHDPE is limited. Often cheaper than virgin.
• rPP: Earliest stage. Food-grade rPP is extremely scarce. Chemical recycling technologies (PureCycle, Plastic Energy) are scaling but not yet at volume.

If recycled content mandates matter to your business, PET gives you the most mature supply chain today. HDPE is catching up. PP is the riskiest bet for near-term recycled content compliance.

Frequently Asked Questions

Which plastic is safest for food packaging?

All three — PET (#1), HDPE (#2), and PP (#5) — are FDA-approved for food contact when manufactured to specification. None contain BPA. PET and PP are the most common for direct food contact in retail packaging.

Which is cheapest per container?

HDPE, typically. Both resin cost and processing costs are slightly lower than PET and PP. PP is lightest per unit volume, which can offset resin price in weight-sensitive applications.

Can I switch between these resins for my existing product?

Usually not directly. Each resin processes differently (different melt temperatures, mold designs, cooling profiles). Switching resin typically requires new molds ($5,000-$50,000+) and production qualification. The container shape may also need redesign to account for different shrinkage and wall distribution characteristics.

Which has the smallest environmental footprint?

Depends on the metric. PET has the highest recycling rate and most mature circular economy. HDPE uses the least energy to produce per unit weight. PP is lightest, reducing transportation emissions. A full life cycle assessment specific to your product and distribution is the only way to give a definitive answer.

What about bioplastics as an alternative?

PLA (polylactic acid) is the most common bio-based alternative but has significant limitations: lower heat resistance than PP, no curbside recyclability, requires industrial composting, and costs 20-40% more. Bio-based PET and PE (from sugarcane ethanol) are drop-in replacements with identical performance, but supply is limited and premiums run 10-25%.