Bioplastics are distinguished by two separate categories:

1. Compostable plastics

Compostable plastics are certified according to the ASTM D6400 Standard and developed using either biobased (e.g. corn, cellulose, etc.) and/or non-renewable, fossil (petroleum-based) resources.  The focus of compostable plastics is based on their function of compostability not on their raw material basis.  Certified, compostable plastic products can contain renewable raw materials.  However there are also synthetic polymers based on fossil, raw materials which are fully compostable according to the ASTM D6400 Standard.    

Any plastic material making the claim of compostability must be proven by recognized testing standards (US: ASTM D6400).  Resins and finished products should be certified by independent, third-party laboratories and labeled with the Biodegradable Products Institute (BPI) compostable logo.  Any product which contains polyethylene, polypropylene, polystyrene or any other traditional plastic material should be questioned for accurate, reliable advertising claims. 

1. Biobased plastics

Biobased plastics are produced using at least 50 percent of renewable resource-based content, such as; sugar, starch, vegetable oils, cellulose, etc.    The focus of biobased plastics is on their raw material basis, not their function of compostability.  Corn, potatoes, cereals, sugar cane and wood are the most commonly used feedstocks. 

Although most biobased plastics are not intended or designed to be compostable, they aid in product sustainability by requiring less energy for production and reduce dependence on petroleum as a raw material.  ASTM D6866 testing methods are used to determine the proportion of bio-content a product or resin has.

Biodegradation occurs when under the right conditions the microbes in the environment can break down materials and use them as a food source. It is a process that can take place in many environments including soils, compost sites, water treatment facilities, marine environments and even in the human body. This is the process that converts carbon into energy and maintains life.

In order for plastics to biodegrade they must go through a two-step process:

1) The long polymer chains are shortened at the carbon-carbon bonds. This process can be initiated by heat, moisture, microbial enzymes or other environmental conditions, depending on the polymer. This step is called “degradation” and you know it is occurring because the plastic becomes weak and will easily fragment.

2) The shorter carbon chains pass through the cell walls of the microbes and are used as an energy source. Biodegradation occurs when the carbon chains are utilized as a food source and are fully converted into water, biomass and carbon dioxide.

The ASTM D6400 Standard for compostable plastics specifies three criteria for compostability

1. Mineralization

• At least 90 percent conversion to carbon dioxide, water and biomass via microbial assimilation.
• Occurs at the same rate as natural materials (i.e. leaves, grass food scraps)
• Occurs within a time period of 180 days or less

2. Disintegration

• Less than 10 percent of test material remains on a 2mm sieve

3. Safety

• No impact on plants, using OECD Guide 208
• Regulated (heavy metals less than 50 percent of EPA prescribed threshold)

Natur-Tec^® resins are produced using a proprietary ReX process.  The process reactively blends compostable polymers, natural polymers, organic and inorganic materials – in the presence of proprietary compatibilizers and polymer modifiers to produce biobased and compostable polymer resin formulations that exhibit unique and stable morphology.

Natur-Tec^® resins and products allow customers to reduce their carbon footprint, while providing superior performance and competitive prices.  Natur-Tec^® biopolymer resins are easily processed on conventional equipment and meet industry standards both for compostability as well as for biobased content.  The broad portfolio of Natur-Tec^® resin compounds tailor to a wide variety of end-use applications and offer competitive performance to traditional plastic materials.

Natur-Tec^® has a uniquely, broad product portfolio which includes:

• Flexible Film:  Bag products, foodservice ware, agricultural film, consumer products, product packaging, etc.
• Injection Molded:  Foodservice ware, consumer products, product packaging, etc.
• Foam:  Packaging, cushioning, insulative packaging, etc.
• Extrusion coated: Foodservice ware, consumer products, product packaging, etc.

Oxo-degradable or simply degradable plastic materials are falsely marketed as biodegradable or compostable.  Oxo-degradable plastic products are manufactured by combining polyolefins with metal containing additives, which when exposed to sunlight allow the material to breakdown into small fragments.

Oxo-degradables cause many severe health and environmental concerns:

• The additives used to trigger the fragmentation process contain heavy metals, proven to cause adverse effects on humans and the environment.
• The tiny fragments left behind cause extreme pollution problems among compost facilities, oceanic pollution and cause bioaccumulation among birds, fish etc.
• The degraded plastic fragments attract and house PCBs and DDTs – when consumed cause endocrine disruption in the food chain.  Endocrine disruption is known to cause significant health problems, including; miscarriages, birth defects and many forms of cancers.

True compostable plastics should be able to prove they meet the ASTM D6400 Standards and carry the BPI logo.  For more information regarding the harmful effects of oxo-degradable plastics please click here.

The BPI is short for the Biodegradable Products Institute.  It is a multi-stakeholder association of key individuals and groups from government, industry and academia, which promote the use and recovery of biodegradable/compostable plastic materials. 

The BPI composting logo is designed to address the confusion that has existed between truly compostable materials and oxo-degradable plastics by building credibility and recognition for products that meet the ASTM D6400 Standards among consumers, composters, regulators and others.  It is designed to be easily recognizable and able to be placed on the actually product as well as packaging and sales literature.

Composting is the natural breakdown of organic material into rich soil known as compost.  Tiny microorganisms found in the soil breakdown organic matter by consuming it as a food source.  Composting organic waste (yard trimmings, food waste, etc) helps to divert organic waste away from a landfill. 

Compost, when added back to land projects promotes healthy plant growth, improves soil moisture retention, amends sandy/clay soils and improves crop nutrient content. 

Natur-Tec^® products are designed to be fully compostable in a professional or municipal compost facility.  These facilities are carefully controlled to maintain the correct balance of moisture, nutrients and temperature needed for full biodegradation. 

Modern day landfills are designed to entomb garbage anaerobically – meaning without oxygen.  Landfills are managed so that very little material actually degrades even if the material is organic.  Landfill excavations have uncovered newspapers that are still readable after almost forty years, ten year old carrots that are still bright orange on the inside and twenty year old steaks that still have meat on the bones.
Biodegradation is an aerobic process – meaning oxygen breathing.  For complete, proper biodegradation, compost facilities have to maintain a carefully controlled balance of moisture, nutrients, temperature and particle size. 

Biodegradation is not the answer to extending landfill space.  Diverting organic material to a compost facility instead of a landfill is a more sustainable solution and allows for the reuse of the final compost material.

A source separated waste diversion program refers to the successful separation of waste streams.  These waste streams include; organics, recyclables and non-organic trash.  Each waste stream is collected separately in clearly labeled containers.  The collection bin for all organic waste is lined with Natur-Tec^® compostable bags; this makes the collection process more efficient and hygienic.  As additional compostable foodservice products (compostable tableware, cutlery, etc.) are introduced into the facility they can also be collected along with the organic food waste. 
The organic waste is collected and hauled by a professional compost facility and the resulting compost can be used for land projects in the community.  Source separated waste diversion programs are ideal for large institutions, cafeterias, schools/universities, government agencies, etc.
Waste diversion programs help divert millions of tons of organic materials away from landfills, reduce garbage hauling/tipping fees and divert organic waste to a compost facility so waste can be reclaimed for land projects. 

To find a professionally managed compost facility in your area, please visit www.findacomposter.com to search for a facility in your area.