Storopack has helped us get through the smoke and mirrors of the sustainable and biodegradable trend in plastics.
OXO-DEGRADABLE PLASTICS
At the most recent PMMI show in Chicago, a growing number of companies were selling biodegradable/compostable plastic film and loosefill. Interestingly, all of them were touting “oxo-degradable” products. The following is a current understanding of the state of the biodegradable plastics today.
DEFINITIONS
The official definitions of degradable, biodegradable and compostable are found in the literature and are repeated by the Bio-Plastics Institute (BPI) an independent certification company, the FTC, and the state of California and are often found on various websites related to the industry:
Degradable Plastic:
· A degradable plastic undergoes a significant change in its chemical structure under specific environmental conditions resulting in a loss of some properties. There is no requirement that the plastic has to be de-grade from the action of "naturally occurring microorganism" or any of the other criteria required for compostable plastics.
Biodegradable Plastic:
· A degradable plastic in which the degradation results from the action of naturally occurring microorganisms such as bacteria, fungi and algae (ASTM D 6400)
Compostable Plastic:
· A plastic that undergoes degradation by biological processes during composting to yield CO2, water, inorganic compounds, and biomass at a rate consistent with other compostable materials and has no visible, distinguishable or toxic residue (ASTM D 6400)
Biodegradability is determined by measuring the amount of CO2 produced over a certain time period by the biodegrading plastic.
· ASTM, ISO and DIN standards require 60% biodegradation within 180 days.
· European CEN EN13432 is the strictest standard, requiring 90% biodegradation within 90 days.
Disintegration is measured by sieving the material to determine the biodegraded size and less than 10% should remain on a 2mm screen for most standards.Eco toxicity is measured by having concentrations of heavy metals below the limits set by the standards and by testing plant growth by mixing the compost with soil in different concentrations and comparing it with controlled compost.
A biodegradable product will only biodegrade if it is in an environment which includes moisture, heat, and microorganisms. Without those three components, there will be no biodegradation.
STANDARDS
The key standard most often referenced is ASTM 6400. This is strictly for compostable plastics. Importantly, it requires that 60% of the material biodegrade in 180 days. This is a very difficult standard – one that no oxo-degradable product can pass. As a result, there is lobbying going on to change the standard to 5 years for 100% biodegradation. Interestingly, California has anticipated this and has passed Bill 1972 stating that if the standard is made less strict, they will use the old standard. CEN EN 13432 and DIN V 49000 are parallel international standards.
In the US the FTC (Federal Trade Commission) regulates product labeling. Their overriding focus is to assure a typical consumer is not misled by product claims. In a recent publication, they specifically note that most garbage is taken to landfills, which are designed by law to keep out sunlight, air and moisture. By definition, it would be almost impossible to claim a film or loosefill would be “biodegradable”.
For products that pass ASTM 6400, there must still be labeling stating the material is compostable but “appropriate composting facilities may not be available in your area”. It is very rare in the US for food products to be separated into the compost stream. Today there is no collection scheme in the US to direct compostable films away from landfills.
OXO-DEGRADABLE
There are several issues with claiming that the oxo-products have any environmental impact. A search of the literature brings up the following:
· Oxo products take 9 months to 5 years to degrade. This is noted in the claims on recent PMMI literature.
· Oxo products can not, by definition, biodegrade in landfills – which is where most US garbage ends up.
· The mechanism of the oxo-products is that the additives act as catalysts to cleave the polymer chains into very small pieces – under 40,000 molecular weight – which can be ingested by micro-organisms.
· There is great debate in the scientific community whether the organisms actually change the form of the plastic. It is agreed that small pieces end up in the bio-mass.
· There has been some chemical analysis of the final bio-mass that has shown styrene monomer and benzene – both carcinogens. If reproducible, the toxicity will also fail ASTM 6400.
BIG PICTURE
Sometimes things can get too technical. If we go back to basics, let’s consider the oxo-biodegradable product. Sellers tout a use rate of 2-3% with the base plastic. Clearly, then, the final product remains 97-98% plastic. There are no bacteria that digest plastic. As a result, after the oxo-product does its work, you are left with all the plastic – just in really small pieces.
This is identical to the products from the 1990’s that simply stitched starch into the polymer matrix to accomplish the same thing, except the final pieces were bigger.
PROVEN TECHNOLOGIES
Materials like PLA (polylactic acid) and Novamont’s Mater-Bi and corn starch based products that meet the ASTM standard. As you might expect, there are issues with these products. PLA film tends to be stiff/brittle. Starch film is relatively dense and heavy. Mixtures of the two are showing promising properties. In all cases the final film is more expensive than polyethylene.
CONCLUSION
Due to outrageous claims and a complete lack of cohesive and understandable standards and definitions in the 1990’s and into the 2000’s, Governments and regulatory bodies are taking charge to protect the public. Laws are slowly being enacted to force products that claim to be biodegradable completely break down into core carbon and water compounds in a relatively short period. Clearly the current ranges of minor additives are not going to be acceptable long term.
Today’s challenge is the expense, as proven bio-products are competing with gasoline additives for corn. Eventually equilibrium should be reached as more corn is planted to meet the growing demand. New PLA capacity is being brought on line and manufacturing technology is evolving to lower the cost. Costs will be further driven lower as demand grows.
Today, Storopack’s best long-term strategy is to focus on starch and PLA-based plastics which pass the current ASTM standard. Currently there are only 2 suppliers that supply starch and PLA-based plastics which limit the availability and cost. There will be others and we expect the price to be lower.
OXO-DEGRADABLE PLASTICS
At the most recent PMMI show in Chicago, a growing number of companies were selling biodegradable/compostable plastic film and loosefill. Interestingly, all of them were touting “oxo-degradable” products. The following is a current understanding of the state of the biodegradable plastics today.
DEFINITIONS
The official definitions of degradable, biodegradable and compostable are found in the literature and are repeated by the Bio-Plastics Institute (BPI) an independent certification company, the FTC, and the state of California and are often found on various websites related to the industry:
Degradable Plastic:
· A degradable plastic undergoes a significant change in its chemical structure under specific environmental conditions resulting in a loss of some properties. There is no requirement that the plastic has to be de-grade from the action of "naturally occurring microorganism" or any of the other criteria required for compostable plastics.
Biodegradable Plastic:
· A degradable plastic in which the degradation results from the action of naturally occurring microorganisms such as bacteria, fungi and algae (ASTM D 6400)
Compostable Plastic:
· A plastic that undergoes degradation by biological processes during composting to yield CO2, water, inorganic compounds, and biomass at a rate consistent with other compostable materials and has no visible, distinguishable or toxic residue (ASTM D 6400)
Biodegradability is determined by measuring the amount of CO2 produced over a certain time period by the biodegrading plastic.
· ASTM, ISO and DIN standards require 60% biodegradation within 180 days.
· European CEN EN13432 is the strictest standard, requiring 90% biodegradation within 90 days.
Disintegration is measured by sieving the material to determine the biodegraded size and less than 10% should remain on a 2mm screen for most standards.Eco toxicity is measured by having concentrations of heavy metals below the limits set by the standards and by testing plant growth by mixing the compost with soil in different concentrations and comparing it with controlled compost.
A biodegradable product will only biodegrade if it is in an environment which includes moisture, heat, and microorganisms. Without those three components, there will be no biodegradation.
STANDARDS
The key standard most often referenced is ASTM 6400. This is strictly for compostable plastics. Importantly, it requires that 60% of the material biodegrade in 180 days. This is a very difficult standard – one that no oxo-degradable product can pass. As a result, there is lobbying going on to change the standard to 5 years for 100% biodegradation. Interestingly, California has anticipated this and has passed Bill 1972 stating that if the standard is made less strict, they will use the old standard. CEN EN 13432 and DIN V 49000 are parallel international standards.
In the US the FTC (Federal Trade Commission) regulates product labeling. Their overriding focus is to assure a typical consumer is not misled by product claims. In a recent publication, they specifically note that most garbage is taken to landfills, which are designed by law to keep out sunlight, air and moisture. By definition, it would be almost impossible to claim a film or loosefill would be “biodegradable”.
For products that pass ASTM 6400, there must still be labeling stating the material is compostable but “appropriate composting facilities may not be available in your area”. It is very rare in the US for food products to be separated into the compost stream. Today there is no collection scheme in the US to direct compostable films away from landfills.
OXO-DEGRADABLE
There are several issues with claiming that the oxo-products have any environmental impact. A search of the literature brings up the following:
· Oxo products take 9 months to 5 years to degrade. This is noted in the claims on recent PMMI literature.
· Oxo products can not, by definition, biodegrade in landfills – which is where most US garbage ends up.
· The mechanism of the oxo-products is that the additives act as catalysts to cleave the polymer chains into very small pieces – under 40,000 molecular weight – which can be ingested by micro-organisms.
· There is great debate in the scientific community whether the organisms actually change the form of the plastic. It is agreed that small pieces end up in the bio-mass.
· There has been some chemical analysis of the final bio-mass that has shown styrene monomer and benzene – both carcinogens. If reproducible, the toxicity will also fail ASTM 6400.
BIG PICTURE
Sometimes things can get too technical. If we go back to basics, let’s consider the oxo-biodegradable product. Sellers tout a use rate of 2-3% with the base plastic. Clearly, then, the final product remains 97-98% plastic. There are no bacteria that digest plastic. As a result, after the oxo-product does its work, you are left with all the plastic – just in really small pieces.
This is identical to the products from the 1990’s that simply stitched starch into the polymer matrix to accomplish the same thing, except the final pieces were bigger.
PROVEN TECHNOLOGIES
Materials like PLA (polylactic acid) and Novamont’s Mater-Bi and corn starch based products that meet the ASTM standard. As you might expect, there are issues with these products. PLA film tends to be stiff/brittle. Starch film is relatively dense and heavy. Mixtures of the two are showing promising properties. In all cases the final film is more expensive than polyethylene.
CONCLUSION
Due to outrageous claims and a complete lack of cohesive and understandable standards and definitions in the 1990’s and into the 2000’s, Governments and regulatory bodies are taking charge to protect the public. Laws are slowly being enacted to force products that claim to be biodegradable completely break down into core carbon and water compounds in a relatively short period. Clearly the current ranges of minor additives are not going to be acceptable long term.
Today’s challenge is the expense, as proven bio-products are competing with gasoline additives for corn. Eventually equilibrium should be reached as more corn is planted to meet the growing demand. New PLA capacity is being brought on line and manufacturing technology is evolving to lower the cost. Costs will be further driven lower as demand grows.
Today, Storopack’s best long-term strategy is to focus on starch and PLA-based plastics which pass the current ASTM standard. Currently there are only 2 suppliers that supply starch and PLA-based plastics which limit the availability and cost. There will be others and we expect the price to be lower.
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