Degradable & Biodegradable bags

Why Degradable or Biodegradable bags/film?

Conventional plastics do not break down. Litter and landfill waste take years, even decades, to degrade. Litter is visual pollution, an eyesore that regulations and educational programs have failed to eliminate. In landfills, not only do ordinary plastics degrade very slowly but also anything contained within them may not reach their full degradation potential. This results in a needless waste of valuable landfill space. Therefore, Degradable/Biodegradable bags are developed to make your daily tasks of waste reduction easier, safer and better for the environment.

What is the difference between degradable and biodegradable?

Degradation is a process whereby very large molecules are broken into smaller molecules or fragments. Normally, oxygen is incorporated into these molecular fragments. Typically, strong, tough plastic films become weak and brittle as a result of oxidative degradation. This outcome is because the molecules of which the films consist become much smaller. Degradation can be caused (initiated) by heat, or exposure to UV light and is enhanced by mechanical stress.

“Degradable Plastic: a plastic designed to undergo a significant change in its chemical structure under specific environmental conditions resulting in a loss of some properties that may vary as measured by standard test methods appropriate to the plastic and the application in a period of time that determines its classification.” [ASTM D883-99] – American Society for Testing and Materials.

Biodegradation is the process by which microorganisms (microbes such as bacteria, fungi or algae) convert materials into biomass, carbon dioxide and water. Biomass is a general term used to refer to the cells of the microorganisms that are using the material as a carbon source to grow on.

“Biodegradable Plastic: a degradable plastic in which the degradation results from the action of naturally-occurring micro-organisms such as bacteria, fungi, and algae.”[ASTM D883-99]

There are two primary differences between ‘degradable’ and ‘biodegradable’. Firstly, heat, moisture and/or UV exposure most often causes the degradation of a degradable product, whereas microorganisms degrade a biodegradable product. Secondly, degradable products tend to take much longer to break down into carbon dioxide, biomass and water.

When degradable plastics break down into smaller molecules, eventually they will be small enough to be consumed by microorganisms and so biodegradation occurs. In essence then, all degradable films will eventually biodegrade but at different speeds.

Biodegradable/degradable plastics can be made from many different sources and materials as listed below:

• Starch based polymers:- Thermoplastic starch based polymers made with at least 90% starch from renewable resources such as corn, potato, tapioca or wheat.
• Polyesters (Bacteria based polymers):- Polyesters manufactured from hydrocarbons (oil or gas). All polyesters degrade eventually, with degradation rates ranging from weeks for aliphatic polyesters(e.g. polyhydroxyalkanoates). Bacteria are an additional treatment used to create a different type of biodegradable polymer.
• Starch or Polyester blends:- Mixed with thermoplastic starch with polyesters made from hydrocarbons.
• Oxo-biodegradable polymers:- These polymers undergo controlled degradation through the incorporation of 'prodegradant' additive (additive that can trigger and accelerate the degradation process). These polymer undergo accelerated oxidative define degradation initiated by natural daylight, heat and/or mechanical stress, and embrittle in the environment and erode under the influence of weathering.
• Photodegradable polymers:- These polymers are those that break down through the action of ultraviolet(UV) light, which degrades the chemical bond or link in the polymer or chemical structure of the plastic. This process can be assisted by the presence of UV-sensitive additives in polymer.
• Water-soluble polymers:- These polymers are those that dissolve in water within a designated temperature range and then biodegrade in contact with microorganisms.

There are two main options for making normal polyethylene into a biodegradable film:

1. Starch based or Biobased (Hydrodegradable)
It is made from corn (maize), potatoes, wheat. This form of biodegradable films meets the ASTM standard (American Standard for Testing Materials) and European norm EN13432 for composting as it degrades at least 60% within 180 days or less.


Examples of polymers with which starch is commonly used:

• Polycaprolactone (PCL)
• Polyvinyl alcohol (PVA)
• Polylactic acid (PLA)

Pros & Cons of Starch based to Additive based film/bag

Pros:
• Degradable & Compostable
• No fossil fuel or very little fossil fuel (if % mixed with traditional polymer)
• Faster degradation
Cons:
• Poorer mechanical strength than additive based example – filling a starch bag with wet leaves and placing curbside can result in the bottom falling out when a hauler picks it up.
• Limited Shelf life
• Can only be composted in a special composting facility.

Typical Application area

Industrial Compostable Facility, Please visit your local city government's website to see if you have an industrial composting facility that accepts residential compost.


2. Additive based (Oxodegradable/Photodegradable)
These films are made by blending an additive to provide a UV / oxidative and/or biological mechanism to degrade them. This typically takes 6 months to 5 years in a landfill site and/or standard composting system. In these films, biodegradation is a two stage process; first the plastic is converted by reaction with oxygen (light, heat and/or stress) to molecular fragments that water can wet, and then these smaller oxidized molecules are biodegraded, i.e. converted into carbon dioxide, water and biomass by microorganisms.


Pros & Cons of Additive based to Starch based film/bag

Pros:
• Cheaper & Proven
• Controlled degradation
• Longer shelf life than most biodegradable films
• Recyclable
• These films look, act and perform just like their non-degradable counterparts, except they break down after being discarded.
Cons:
• Made using fossil fuel
• Degradation depends on conditions of heat, light, stress, air etc.

Typical Applications

Trash Bags, Garbage Bags, Compost Bags, Carrier bag, Agricultural Film, Mulch Film

When choosing the biodegradable/degradable film that you are going to use, you have to ask several questions in order to get the correct type of biodegradable film to suit your requirements:

1. What is the cost of the film absolutely and relative to other film options?
2. What is its function? - Is it a mailer, a can liner, box liner, a bag for a compost pile?
3. What will happen to this product once discarded using the intended product? Consider Waste collection and landfill costs, Recycling and Waste-to Energy possibilities
4. How is the plastic film going to be stored and for how long?

• Polybags Limited
• Richmond Plastics Limited
• Abbey Polythene
• Britton Taco Limited
• Ecover UK

Common materials used for Biodegradable/degradable film:

• Low density polythene blended with degradable additive
• Medium density polythene blended with degradable additive
• High density polythene blended with degradable additive
• Recycled polythene blended with degradable additive
• Starch based plastics

Available Thickness

80 Gauge(20microns) to 1000 Gauge(250microns)

Tolerances:

Normally, Biodegradable film/bags in Great Britain should follow widely accepted industrial standards according to British Standard – see BS7344, 1990

• Width: Plus or minus 3mm (0.125”) or 2% whichever is greater
• Length: Plus or minus 6mm (0.25”) or 2% whichever is greater
• Gauge: Plus or minus 10%

1. Food Contact – To use Degradable/Biodegradable film or bags inside European Union, in contact with food should comply with the relevant legislation on food contact including Great Britain.
• Great Britain: Statutory Instrument, 1998 No. 1376 and BPF-BIBRA (1995), Polymer Specification 4, Polyethylene
• EU: Commission Directive 90/128/EEC, 92/39/EEC, 93/9/EEC, 95/3/EEC and 96/11/EC, Section A.
• Example of a company comply with food contact: Polybags Limited
2. Medical use – Similarly, to use Degradable/Biodegradable film or bags inside European Union, to produce containers for preparations for medico-pharmaceutical purposes should comply with the following regulation:
• European Pharmacopoeia - Monograph 3.1.3 "Polyolefin's" for medico-pharmaceutical purposes.
• The final responsibility for the decision of whether a material is fit for a particular application lies with the pharmaceutical firm.
• Example of a company comply with medical use: Polybags Limited

• Flat Biodegradable/Degradable bags: Standard Biodegradable/Degradable bags often called by flat bags. It is used for general purpose.
• Gussetted Biodegradable/Degradable bags: Plastic bags with fitted bottom and expandable sides (gusset) form to the shape of your product.
• Perforated Biodegradable/Degradable bags: Perforated bags have a perforation for a easy tear off from either a bunch of bags or roll.
• Plain Mini grip/Self seal/Reclosable bags: Plain Self-seal biodegradable/degradable bags with interlocking closure that can be used over and over again. Ideal where you want to secure contents and avoid leakage or contamination, no need of heat sealing.
• Plain Self seal biodegradable/degradable bags with write on panel: Plain self-seal biodegradable/degradable bags with write on panels is used for content identification, coding etc. Easy to label contents using a marker, ballpoint pen or pencil.
• Biodegradable/Degradable Specimen bags: Biodegradable/Degradable Specimen bags comes with outer pouch for record cards. Ideal for use in hospitals, medical labs to safely transfer specimens and paperwork.
• End weld (bottom) Biodegradable/Degradable bags: End weld bags are generally welded in the bottom. Bottom weld offers added strength for packing heavier items.
• Side weld Biodegradable/Degradable bags: When bags welded on the sides of the bags is referred to Side weld bags. Side weld bags are ideal for packaging lighter materials such as greeting cards/envelopes.

• Biodegradable/degradable bags can be used for any application however it is popular for following use:
  
• Refuse sacks
• Bin liners
• Carrier bags
• Bread bags
• Compostable bags

• home use 'Compobag' & wrapping sheet
• standard - biodegradable clear bags
• heavy-duty biodegradable clear bags
• bin liners and refuse sacks
• biodegradable carriers
• biodegradable loose fill

BBC News - All Tesco bags 'to be degradable, 10th May'06

Supermarket giant Tesco has said all its carrier bags will be degradable from September.

The bags break down in as little as 60 days into materials such as carbon dioxide and water with no harmful residue, unlike plastic bags.

The firm hopes a billion fewer plastic bags a year will be used in a bid for it to be more environmentally-friendly.

The Co-op first introduced degradable bags in 2002 and Sainsbury's have trialled compostable bags.

Bag tax

Tesco chief executive Sir Terry Leahy announced the measure as part of a 10-point plan, which include halving Tesco stores' energy use by 2010 compared with the year 2000.

But Liberal Democrat environment spokesman Chris Huhne said he would rather see a tax on plastic bags introduced.

"Biodegradable plastic bags in themselves can have an adverse environmental impact by creating greenhouse gases within landfill sites.

"The government should look again at introducing some form of plastic bag tax which will make supermarkets and consumers think twice before they give away and use plastic bags in the first place."

The company has also pledged to reduce deliveries to its local Express convenience stores to cut congestion.

It aims to double the amount of material customers return to stores for recycling by 2008.

Addressing the Work Foundation think tank, Sir Terry urged the government to back its plans by allowing developments to go ahead.

"Much of this new sustainable technology, for example wind turbines at our stores, requires planning permission", he said.

Tesco first introduced degradable bags in its stores two years ago.

It estimates 719 million degradable carrier bags have since been used by customers, saving the equivalent of 6,035 tonnes of non-degradable plastic.

Sainsbury's launches compostable packaging, 9th September'06 - Dailymail

Sainsbury's is to sell 500 of its own-brand products in 'compostable' packs to cut down on packaging waste.

Fruit and vegetable wrappers and ready-meal packs can be put on compost heaps with garden clippings and food waste.

The store chain is calling on other retailers to follow suit as well as urging the Government to provide compost bins for all homes.

According to Sainsbury's, the compostable packaging - which was tested on a small number of organic products - will reduce plastic waste by around 3,550tons per year.

It will also save 4,010tons of fossil fuel used in manufacturing the plastic and reduce rubbish collected for landfill.

The packs are made from maize, sugar or plant-based starch which breaks down into carbon dioxide and water.

In warm weather, the packaging may break down in as little as a fortnight.

From this month, Sainsbury's will print advice such as 'please recycle' or 'sorry, not recyclable' on its own-brand lines.

Almost half of its organic fruit and vegetables will be in compostable packaging from this week, rising to 80 per cent by January. The scheme will extend to all its ready meals by September 2007.

Chief executive Justin King said: 'We're confident that putting 500 types of our food, from ready meals to organics, in compostable packaging will significantly help to reduce the packaging that most threatens the environment.

'It also creates an opportunity for customers to dispose of their own waste at home.'

Mr. King said he hoped customers would be able to halve their household waste by composting as well as contributing to safeguarding the environment.

The initiative reflects the drive by all the UK's major supermarkets to 'go green'.

Tesco recently launched a scheme to reward customers for requesting fewer plastic carrier bags.

Sainsbury's has around 10,000 ownbrand lines, and is the single largest user of compostable packaging in Europe.

Friends of the Earth welcomed Sainsbury's drive to cut packaging waste, but resource campaigner Dr Michael Warhurst said: 'We hope it goes further and phases out all non-recyclable packaging.

'It must also take urgent action to reduce the impacts that its operations have on the environment and farming communities.

'This announcement is a step in the right direction, but it has a long way to go before it can be viewed as a green grocer.'

Jane Gilbert, of the Composting Association, said she hoped every home would be given information on how to compost at home.

Leading supermarkets spend £15billion a year on packaging and customers throw away 4.5million tons of it a year.

IKEA REAPS ENVIRONMENTAL REWARDS WITH CORN

IKEA goes biodegradable and introduces the UK’s first organic corn starch carrier phasing out plastic bags completely.

IKEA goes biodegradable and introduces the UK’s first organic corn starch carrier phasing out plastic bags completely.

To support World Environment Day in June 2006 IKEA UK started charging for carrier bags and made a corporate pledge to reduce plastic bag consumption by 70% and introduce a biodegradable carrier bag by September.

IKEA will be the first retailer in the UK to offer a ‘compostable’ corn starch carrier bag. The bag will be made from starch extracted from corn and will naturally break down in a compost bin. The bag will cost 10p and the money made from charging for the bags will continue to be donated to the organisation Community Forests.

By October 2nd IKEA will have stopped using plastic bags completely. Every year an estimated 17½ billion plastic bags are given away by supermarkets. This is equivalent to over 290 bags for every person in the UK. Most carrier bags never get a second use they get thrown straight in the rubbish bin and take many years to degrade. Some plastic bags are marketed as degradable i.e. the plastic breaks down but is still there just in smaller fragments.

Mr. Charlie Browne Environment Manager at IKEA UK said:
“Since we started charging for carrier bags back in June the scheme has been a fantastic success. Over night we saw huge reductions in consumption and all indications are that we will have reduced our consumption by 97% from 32 million last year to 900,000 this year which is far beyond our original expectations.

Our customers are overwhelmingly supportive mainly due to the fact that we make no profit from the project and they are being given a simple choice to help the environment. So the next logical step for us was to take traditional fossil fuel plastic out of the equation.”

Note to Editor

Somerfield introduces disappearing bags - Degradable bags

Somerfield has introduced an environmentally responsible alternative to the standard carrier bag in response to growing concerns about landfill and littering. The new carrier bags look identical to traditional ones, but are made from Europackaging degradable polythene. This important step is fully supported by The Soil Association as a positive contribution to the environment.

Our new carriers were introduced to selected stores on 26th November 2002 and will be rolled out nationwide from February 2003 onwards. Programmed to have a usable life of 18 months, they can be used and reused just like conventional carrier bags, but will biodegrade once put into commercial scale compost heaps.

To make our degradable launch a 'joined-up' initiative, we will also be introducing bin liner packs in store made from the same degradable material. The technology is branded as DW3™ and utilises a special additive, which allows time-controlled total degradation of the plastic material to leave only water, carbon dioxide and biomass. This form of degradable plastic is unique to Europackaging and is already used for other applications, such as refuse sacks, fruit & veg packaging and mailing film.

If you prefer a more durable bag that you can reuse, our 'bag for life' is available for 10p. While it is not degradable, you can still contribute to the environment by using it over and over again.

Making a positive contribution

Each year, the UK grocery industry uses enough carrier bags to carpet the planet twice and these conventional carriers take 100 years or longer to degrade. Even if we try to reuse plastics, they still end up in landfill, as there are few schemes available to recycle them due to the large range of polymer types involved. Conventional plastic bags in landfill, delay domestic 'green' waste (potato peelings, tea bags, etc..) inside them from naturally biodegrading, because the bacteria activity is encapsulated within the plastic. This is where degradable bags can make a big 'hidden' effect, creating available space and helping landfill settle quickly, instead of pockets of unsettled rubbish.

On top of this we believe that these new bags will help to reduce the long-term effects of problems such as littering, enabling Somerfield customers to contribute to the environment without any massive change to their current behaviour. The new DW3™ bags can simply be used and re-used and then responsibly disposed of when they will disappear completely.

The process

The bags are just as strong as conventional plastic bags, but are programmed to have a usable life of 18 months. After this, the structure starts to weaken as the bags begin to degrade. The end result is that the plastic loses all of the water and gas within its structure to leave minerals that are compatible with soil.

Somerfield bags are not reliant on microbial presence (biological activity) to break down, so they are not classified as just biodegradable, but if they are put into commercial scale composting** heaps, they will eventually become biodegradable.

The technology has been independently tested and proven to be environmentally safe, leaving no toxic substances at the end of the degradation process, and has also been tested as safe for direct food contact under EU standards.

** Composting exceeding the minimum temperature of 55°C required in The Composting Association Standards for Composts. (Ref; Emily Nichols 01933227777).

BBC News - Degradable carrier bags launched, 2nd September'02

The country's first degradable carrier bag is being provided at Co-op supermarkets.

The bag, available free of charge from Monday, will disintegrate to practically nothing within three years, it is claimed.

The move comes as the government considers whether shoppers should face a 10p bag tax - similar to one already in force in Ireland.

Although the Co-op is the first to convert, it is understood bigger high street names may follow suit before the end of the year, in an effort to cut waste.

Shoppers in Britain are estimated to use up to 20 billion plastic carrier bags a year.

Only one in every 200 is recycled and each takes about 100 years to degrade.

Co-op claims the new degradable bag will be strong and reusable, with a special additive which starts the degrading process after 18 months.

This can occur either in landfill sites, where most carrier bags end up, or above ground.

Problems

And all that remains are small amounts of carbon dioxide, water, and certain minerals.

However, Friends of the Earth questioned whether any such petrol-based carrier could be seen as environmentally friendly.

Mike Childs, senior campaigner at the group, said: "One of the problems with degradable plastics is when they are thrown into a hole in the ground and break down, as there is no oxygen, the carbon turns into methane which is a greenhouse gas.

"We would like to see plant-based plastics being used or, even better, reusable bags."

The degradable carrier is provided by Hertfordshire-based Symphony Environmental Ltd, part of Symphony Plastics.

And Michael Stephens, technical director at Symphony, said Friends of the Earth was misinformed.

"There is oxygen in landfill sites in the upper layers and even so, the amount of carbon in one bag is the same as a human produces eating a slice of bread," he said.

Although the Co-op bag is the first such carrier available in Britain, Symphony already makes degradable rubbish bags using the same technology.

Environment Minister Michael Meacher is believed to be considering a tax on plastic bags following the success of a scheme in Ireland.

The 9p tax was introduced in March and in the first three months, bag usage dropped by 90%.

Require plastic bags that degrade — 33.1%

Set up a bag-recycling infrastructure — 28.9%

Educate the public to avoid litter — 27.4%

Ban plastic bags — 6.6%

Tax plastic bags — 3.9%

Total Votes: 332
Poll Date: September 16, 2004