A 1970s Compostable Plastic Patent the World Forgot

If you search the U.S. and European patent databases for filings between 1970 and 1980 referencing terms like “biodegradable polymer,” “polylactic acid,” “compostable plastic,” or “polyhydroxyalkanoate,” you’ll find a surprising volume of work. Multiple research groups across multiple countries filed patents describing plastic-like polymers — derived from corn starch, sugarcane, bacterial fermentation, or agricultural waste — that could biodegrade in soil within months. These patents described manufacturing processes combining fermentation, polymerization, and extrusion to produce materials with properties similar to polystyrene but with end-of-life biodegradability that no conventional plastic could match.

The patents were granted. Some were licensed to small companies exploring applications in agricultural mulch films and disposable packaging. And then most of them disappeared from the commercial conversation for nearly 30 years.

The work of the 1970s essentially described what would become modern PLA (polylactic acid) bioplastic, except 25 years before NatureWorks commercialized PLA at industrial scale in the late 1990s. The chemistry was understood. The applications were identified. The patents were filed. And yet the category stalled for a generation.

This story is more than a historical curiosity. Understanding why early compostable plastic patents didn’t scale, what changed to enable today’s bioplastic industry, and what early formulations reveal about the constraints we still face helps frame where the category is going next. The 1970s patents are a window into both how technology develops and how it sometimes gets buried until the broader conditions support its commercialization.

What the Early Patents Described

The 1970s compostable plastic patents typically described formulations using:

• Corn starch as the primary feedstock — converting starch to glucose, then to lactic acid through bacterial fermentation.
• Polymerization of lactic acid — using catalysts and controlled temperature to form polylactic acid chains.
• Processing into films and molded items — extrusion through standard plastic processing equipment.
• Documented biodegradability — soil testing showing breakdown within 90-180 days under aerobic conditions.

The chemistry was essentially identical to what NatureWorks Ingeo PLA does today. The patents described both the polymerization chemistry and downstream processing — everything needed to manufacture compostable plastic at industrial scale, decades before “industrial scale” actually happened for this category.

Other 1970s patents covered:
– Cellulose acetate film formulations for compostable packaging (extending earlier 1900s cellophane technology).
– Bacterial polyhydroxybutyrate (PHB) production — early PHA technology that wouldn’t be commercialized at meaningful scale until the 2010s.
– Starch-based plastics with various plasticizers and additives.
– Mixed-substrate biopolymers using agricultural waste streams.

The 1970s and early 1980s represented a real surge in bioplastic research, with multiple research teams in the US, UK, and Japan pursuing the technology.

Why Did the Technology Stall?

Several factors combined to prevent 1970s compostable plastic technologies from reaching commercial scale at the time:

Oil prices were low. Despite the 1973 oil crisis, oil prices in the 1970s averaged $30-50 per barrel (inflation-adjusted to 2026 dollars). Conventional plastics were dramatically cheaper to produce than bioplastics. The cost gap was 4-8x, much larger than today’s 2-3x gap.

Manufacturing scale was missing. Bioplastic production at the 1970s level was lab-scale to pilot-scale. Building industrial-scale manufacturing required significant capital investment that wasn’t justified at then-prevailing prices and demand.

Demand was minimal. Environmental awareness in the 1970s was rising but the specific concept of “compostable plastic” had no market pull. Recycling wasn’t yet a household practice. The waste-management infrastructure that would later create demand for compostable alternatives didn’t exist.

Performance gaps were significant. Early bioplastics had real performance limitations vs conventional plastics: lower temperature tolerance, higher moisture sensitivity, lower mechanical strength. These gaps required either application-specific use cases or further chemistry development.

Regulatory frameworks didn’t exist. No certifications for compostability existed in the 1970s. BPI wasn’t founded until 1999. The infrastructure for verifying claims and providing buyer confidence in compostable products was missing.

Composting infrastructure was minimal. Even if compostable plastics were available, there was almost no commercial composting capacity to process them. The end-of-life pathway didn’t exist.

Research funding shifted. As oil prices dropped in the 1980s, government and industry funding for alternative materials research declined. Many of the research teams from the 1970s dispersed to other fields.

The combination meant that even patents with sound chemistry didn’t translate to commercial products. The technology was ready; the world wasn’t.

The Period from 1980-1995: The Quiet Decades

The 1980s and early 1990s saw relatively little compostable plastic activity in commercial channels. The technology continued to be developed in academic settings but commercial applications were limited to:

• Specialty agricultural mulch films (small market, limited geographic adoption).
• Some medical applications (sutures, drug delivery).
• Limited research on packaging.

A few companies attempted commercialization but most failed or scaled back. The economics didn’t work, the infrastructure didn’t exist, and consumer/customer demand was insufficient.

This period is sometimes called the “valley of death” for bioplastics — between early technology demonstration and eventual commercial scale. Many promising technologies die in this valley because the economic and infrastructure conditions to support them haven’t yet emerged.

What Changed in the Late 1990s

The conditions that enabled bioplastic commercialization came together in the late 1990s:

Environmental regulations strengthened. Recycling mandates, landfill restrictions, and emerging waste reduction policies created cost pressures on conventional plastic disposal.

Composting infrastructure grew. Municipal composting programs expanded in Europe and the US, creating actual end-of-life infrastructure for compostable products.

Oil prices rose. From late-1990s lows of $20/barrel, oil prices climbed substantially over the next two decades, narrowing the cost gap with bioplastics.

Manufacturing scale became possible. Companies like Cargill (NatureWorks) had the capital to invest in industrial-scale PLA production, which dropped unit costs significantly through scale economies.

Consumer awareness grew. Environmental consciousness, popularized through publications and advocacy in the 1990s and 2000s, created demand for sustainable alternatives.

Brand sustainability commitments emerged. Major brands began making sustainability commitments that included packaging materials. This created demand that justified manufacturing investment.

Certification frameworks established. BPI (founded 1999) and ASTM D6400 (published 1999) created the verification frameworks that enabled buyer confidence.

These factors took 20+ years to mature. The 1970s technology was always going to need this broader infrastructure development before it could commercialize. The patents were ahead of their time by 25-30 years.

What the Early Patents Reveal About Today’s Constraints

Studying the 1970s patents alongside today’s PLA technology reveals what’s truly different and what’s essentially the same:

Essentially unchanged:
– The core polymerization chemistry of PLA hasn’t changed dramatically. The catalysts and conditions have been refined but the basic process is the same.
– The compostability mechanism — bacterial degradation of the ester bonds in PLA — is the same biological process.
– The feedstock (corn starch in the US, sugarcane in Brazil) is similar to what early patents described.

Significantly improved:
– Manufacturing scale and cost. PLA is now produced at 500,000+ metric tons per year, with unit costs 60-80% lower than 1970s estimates would have projected.
– Material grades. Modern PLA is available in dozens of formulations optimized for different applications (clear films, opaque rigid items, fibers, foams). 1970s patents described a much narrower formulation range.
– Processing equipment. Standard plastic processing equipment can now run PLA with minor modifications. 1970s equipment was less compatible.
– Certifications. Modern PLA is certified by BPI, ASTM, TÜV Austria, and others, providing buyer confidence that 1970s patents could not.
– Additives and blends. PLA can be blended with other bioplastics (PHA, PBAT, starch) to tune properties for specific applications. 1970s patents described simpler formulations.

Still constrained:
– Cost. PLA still costs 2-3x conventional plastic. The gap has narrowed but not closed.
– Heat tolerance. PLA still softens at 105°F unless crystallized to CPLA. This was a 1970s limitation; it remains a 2020s limitation.
– Home compostability. Standard PLA still requires commercial composting temperatures. This was identified in 1970s patents; it remains true.
– End-of-life infrastructure. Despite expansion, commercial composting still isn’t universally available. The pathway is still incomplete.

These constraints are now being addressed by next-generation bioplastics (PHA for home compostability and marine biodegradation, cellulose-based films, mycelium materials), but the 1970s identification of these constraints proved durable.

Other Forgotten Patents Worth Knowing

Several other 1970s and early 1980s patents described technologies that have since been independently reinvented or rediscovered:

1977 patent for mycelium-based composite materials. A research team filed patents for using mushroom mycelium to bond agricultural fiber substrates. The technology stalled for commercialization reasons similar to PLA. Ecovative independently rediscovered and patented similar concepts in the early 2010s and has built a successful business around them.

1979 patent for bacterial cellulose production. Described controlled cultivation of bacteria to produce pure cellulose fibers. Now reemerging as a potential next-generation packaging material.

1981 patent for algae-based polymers. Described extraction of polymer-forming compounds from cultivated algae. Algae-based plastics are now being commercialized by several startups.

1983 patent for chitosan films from crustacean waste. Described compostable films made from shrimp and crab shell waste. Now commercialized in specialty packaging.

1975 patent for compostable agricultural mulch films. Described biodegradable plastic mulch for farming applications. The technology partially commercialized in the 1990s but has accelerated recently as agricultural sustainability has become a priority.

Studying these forgotten patents alongside contemporary commercial products reveals a striking pattern: many “innovative” current technologies have technical precedents from the 1970s-1990s. What’s new is often the manufacturing scale, the supporting infrastructure, and the market demand — not the underlying technology itself.

What This Means for Today’s Compostable Industry

Several implications worth reflecting on:

Technology readiness ≠ commercial readiness. Having the chemistry doesn’t mean having the market. The 1970s teams had the chemistry; they lacked everything else. Today’s compostable industry has both the chemistry AND the supporting infrastructure (manufacturing scale, composting infrastructure, certifications, consumer demand, regulatory pressure) that enables commercial scale.

Patents protect ideas, not commercial success. Many 1970s patents are now expired and the technology is freely usable. The current bioplastic industry isn’t reinventing the chemistry; it’s commercializing what was always technically possible. The competitive advantage today is in manufacturing scale, distribution, brand, and ecosystem-building rather than in proprietary chemistry.

Sustainability transitions take decades. The bioplastic category took 25+ years from technical readiness to meaningful commercial scale. Other emerging materials (PHA, mycelium, algae-based) are likely on similar timelines. Patience and persistent investment matter.

Future categories may be hiding in plain sight. Just as 1970s PLA patents went unnoticed for decades, today’s emerging research likely includes future commercial categories that won’t reach scale for 15-30 years. The bioplastic industry of 2050 will probably use technologies that are now in research or pilot stages.

The Bigger Lesson

The story of the 1970s compostable plastic patents is a story about how innovation actually happens — not as a single “eureka moment” followed by immediate adoption, but as a long process of technology development, market readiness, infrastructure building, regulatory framework establishment, and gradual cost reduction through scale.

The patents that “the world forgot” weren’t actually forgotten; they were dormant, waiting for the conditions that would make their commercialization viable. Those conditions took 20-30 years to mature. When they did, the underlying technology was essentially ready — the work of the intervening decades was mostly about everything else (scale, infrastructure, certification, demand).

For today’s compostable industry, the lesson is that current technologies will mature too. PHA, mycelium, algae-based plastics, advanced cellulose products — these are at similar stages today to where PLA was in the 1970s. The next 15-30 years will likely see these technologies mature through the same combination of scale, infrastructure, regulation, and demand that enabled PLA.

The forgotten patents are also a reminder of how much depended on factors beyond the inventors’ control. The 1970s chemists who developed early PLA had the technology. They couldn’t control oil prices, composting infrastructure, regulatory frameworks, or consumer demand. The chemistry was just one piece of what was needed.

For sourcing compostable products that are now mainstream — built on decades of technology development and infrastructure investment — see https://purecompostables.com/compostable-food-containers/ for food container options that use modern PLA, cellulose, and bagasse substrates, and https://purecompostables.com/compostable-cups-straws/ for cup categories.

Patents Worth Remembering

The 1970s compostable plastic patents are now mostly expired, freely usable by anyone. Many of the chemists who filed them have since retired or passed away. But the chemistry described in those filings is now embedded in millions of PLA cups, films, and packaging items used globally each year. The work didn’t go to waste; it just took longer than expected to flower.

If there’s a single takeaway from the forgotten patent story, it’s this: technology development is rarely linear, rarely predictable, and rarely follows the conventional narrative of invention-then-commercialization. The compostable products you use today carry the imprint of work done in obscurity decades ago by people whose names you’ll never know. The current market exists because that early work was done, even though it didn’t pay off for those who did it.

The patents the world forgot weren’t forgotten by everyone. They were stored, indexed, and waiting in patent databases for the conditions that would make them commercially viable. When those conditions arrived — driven by environmental concern, oil prices, infrastructure development, and consumer demand — the technology was ready to scale. The story of the bioplastic industry isn’t really about invention. It’s about how invention waits for the world to catch up.

For B2B sourcing, see our compostable supplies catalog or compostable bags catalog.

For procurement teams verifying compostable claims, the controlling references are BPI certification (North America), EN 13432 (EU), and the FTC Green Guides on environmental marketing claims — these are the only sources U.S. enforcement actions cite.