The Three Difficulties in Selecting Biodegradable Materials

        In today’s environmentally conscious world, 68% of consumers are willing to pay a 10-15% premium for truly biodegradable products (Nielsen Research 2024). But with all the “eco-friendly materials” on the market, what’s the difference between PLA, PBAT and PHA? Which one really suits your needs?

Part I: A Quick Comparison of the Three Major Materials

Core Properties Comparison Table (Updated 2024)

Characteristics PLA PBAT PHA

Raw Material Sources Corn/Sugar Cane Starch Petroleum-based + Biobased Microbial Fermentation

Degradation Condition Industrial Composting (58-60°C) Soil/Composting Seawater/ Soil/Composting

Degradation Time 6-12 Months 3-6 Months 2-4 Months

Heat Resistance 60°C 80°C 120°. C

Flexibility Brittleness High elasticity Medium

2024 Price $2.1/kg $3.0/kg $4.2/kg

Part II: Material Selection by Usage Scenarios

Scenario 1: Food Packaging

Best Choice: PLA (high transparency, suitable for cold drink cups, salad boxes)

Alternative: PHA (heat-resistant up to 120°C, suitable for lids of hot drink cups)

Lightning Reminder: PBAT is not suitable for contact with oils and fats (easy to be deformed)

Scenario 2: Shopping Bags / Garbage Bags

Preferred Material: PBAT + PLA Blend (combining strength and degradation)

Measured Data Pure PLA bag: load-bearing 5kg easy to break

PBAT hybrid bag: load-bearing up to 15kg

Scenario 3: Marine products

The only choice: PHA (currently the only one certified for marine degradation)

Cases:

Danish ECONYL uses PHA to make biodegradable fishing nets

6-month seawater degradation rate of 92% (SGS test)

Scenario 4: Agricultural ground cover

The best solution: PBAT (cost-effective, degradation starts in 3 months) (degradation)

Comparison experiment:

PLA mulch: easy to be brittle in low temperature

PHA mulch: too costly (2.3 times more than PBAT)

Part III: 2024 Shopping Guide

1. Recognize certification marks

✅ PLA: ASTM D6400 industrial composting certification is required

✅ PBAT: should be certified for composting by EN 13432

✅ PHA: TÜV Marine Degradation certification is recommended

2. Be alert to common scams

❌ “100% degradable” but no indication of the conditions and time

❌ Labeling of PBAT as “fully biobased” (which actually contains 

❌ Passing off oxo-degradable plastics as PHA

3. Cost optimization tips

Requirements Economical solution High-end solution

Short-term use PLA+starch blend Pure PHA

Flexibility required PBAT+PLA(7:3) PHA copolymer

Exposure to high temperatures PLA+mineral filled PHA

Part IV: Latest Industry News

1. Technological Breakthroughs

PLA:

Toray develops heat-resistant PLA (up to 100°C)

Cost is expected to drop to $1.8/kg by 2025

PHA:

Danimer realizes mass production of methane fermentation

China’s production capacity will grow by 300% in 2024

2. Policy Directions

EU: PLA tableware needs to be clearly labeled as “industrial compost” starting from 2025

China: subsidies for PBAT films PBAT film included in agricultural machinery subsidy catalog

US: FDA accelerates PHA food contact approval