Carbon Ready Reckoner – Worked Example
Reduced sugar blackcurrant jam
This worked example shows how the WRAP Carbon
Ready Reckoner can be used to provide insight into
the carbon footprint of reduced sugar blackcurrant
jam in glass jar
Date: October 2013
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Reduced sugar blackcurrant jam
Pack description
Itemise and describe all packaging components.
Consumer unit (primary packaging)
The consumer unit is the packaging the consumer takes out of the shop.
Some products are sold in collations, and the entire collation would be
regarded as the consumer unit.
This consumer unit consists of three packaging components:
 glass jar with 69mm twist off finish;
 steel cap 69mm twist cap; and
 paper label – varnished paper with full colour printing covering 95%
of the circumference of the jar.
The WRAP Carbon Ready Reckoner does not assess minor materials,
such as the can liner and hot melt adhesive on the label, so these are
not included.
To calculate the impact of changes, the number of consumer units
produced per annum is required. In this example, one million jars of
blackcurrant jam are sold per annum. If this pack format were used for
a range of fruits, then the total number of consumer units produced in
the range could be included in the assessment.
This jar contains 400g of jam, which provides 28 average portions.
Before removing the product, it is noted that the headspace is not
excessive (excessive headspace may indicate an oversized jar).
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Reduced sugar blackcurrant jam
Product information
Information required
Product weight per pack (g or ml)
Servings per pack
Number of packs per year
Existing pack
400g
28
1,000,000
Secondary packaging
The secondary packaging is the packaging used to collate consumer
units for distribution, and is not intended to be sold with the product.
Typical secondary packaging includes corrugated board boxes, shelfready display packaging, trays, and shrink-wrap film.
The secondary packaging for the six jars of 400g blackcurrant jam
consists of three packaging components:
 corrugated board tray with bleached white outer layer, externally
printed with two (red and black) colours, approximately 40%
coverage, sealed with hot melt adhesive at four corners;
 shrink film; and
 self-adhesive white label printed with product details and bar code.
Reduced sugar blackcurrant jam
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While considerable savings may be achieved by the use of reusable
transit packaging, the WRAP Carbon Ready Reckoner is not able to
assess this as an existing component or new improvement. The Carbon
Ready Reckoner also does not assess minor materials, so the hot melt
adhesive is not included.
Palletisation
The WRAP Carbon Ready Reckoner will calculate savings from improved
pallet utilisation, but does not include savings from changes in tertiary
packaging such as stretch-wrap, layer boards, and pallet top covers.
Changes in size to the consumer unit and secondary packaging may
affect the number of units that may be placed on a pallet or contained
within another shipment unit, such as a Pal-box. Details of pallet
configuration and transport will be needed to calculate distribution
savings from reductions in pack weight.
Packaging and transport data
Packaging materials and weights
Each packaging component is weighed to +/- 0.1g and the weight and
material recorded as shown on the table below. Reference can be made
to packaging specifications for weights, but actual pack weights should
be checked.
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Reduced sugar blackcurrant jam
Consumer unit
 Glass jars are manufactured using a number of moulds which wear
with use; the average weight of the glass jar was calculated from a
sample of 24 jars. As flint (clear), green, and amber glass have
different recycled content it is necessary to note the type of glass.
 The cap lid was calculated from the total weight of a batch of 50
components.
Existing components – consumer unit
Component name
Glass jar
Cap including liner
Paper label
Existing material
Current weight (g)
Glass flint
215.3
Steel
11.4
Other paper/card
1.3
Secondary packaging
 The average tray weight was calculated from the total weight of a
batch of 10 trays.
 The average weight of the shrink wrap was calculated from the total
weight of 10 shrink wraps
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Reduced sugar blackcurrant jam
Existing components – secondary packaging
Component name
Tray
(2x3 cans size)
Existing material
Corrugated board
28.3
PE Film/bags
15.0
Other paper/card
0.8
Shrink-wrap
Paper case label
Current weight (g)
Palletisation and transport data
This data is used to calculate the carbon impact of packaging changes
on transport. The data required is:
Palletisation and transport data
Information required
Type of vehicle used for delivery
Average one-way distance to
retailer or RDC (km)
Existing
Rigid truck used most often –
capacity up to 17tonnes
150km
Number of consumer units / case
6
Number of cases per layer
30
Number of layers per pallet
7
Number of consumer units per
pallet
Number of pallets per vehicle
1080
(6 jars/case x 30 cases/layer x 6 layers)
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Reduced sugar blackcurrant jam
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A range of delivery vehicles are used to ship to various RDCs, so most
typical vehicles were selected and average distances were calculated at
150 km (one way).
The vehicle options are limited to:
 van (less than 3.5tonnes load capacity);
 rigid vehicle (3.5 to 7.5tonnes load capacity);
 rigid vehicle (7.5 to 17tonnes load capacity);
 articulated vehicle (3.5 to 33tonnes load capacity); and
 articulated vehicle (over 33tonnes load capacity).
In this case a rigid (>17tonne) vehicle is assumed. The number of
pallets of this product that this vehicle will carry is 16.
Pack improvements
The WRAP Carbon Ready Reckoner will calculate carbon savings from
various pack improvements. Each is considered as it applies to this pack
of blackcurrant jam. This pack was compared with other 400g jars of
fruit on the market. Some data on the WRAP UK Packaging Benchmark
Database is available at:
www2.wrap.org.uk/retail_supply_chain/research_tools/tools/uk_packagi
ng_benchmark/index.html Packaging suppliers may be able to offer
alternative pack options.
Potential improvements to reduce carbon impact were considered for
each pack component. The factors included in the WRAP Carbon Ready
Reckoner are:
 packaging weight;
 product concentration – number of servings/portions;
 secondary packaging or palletisation;
 glass: colour and/or recycled content;
 other materials: recycled content and/or recycling rate; and
 other changes (listed at end of section).
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Packaging weight
Glass jar: There are lighter jars available in the market. The jar
weight can be reduced from 215.3g to 171.4g with a reduction of 43.9g
in weight. The lighter jar has capacity of 454g, an additional 54g more
than the current jar. The number of servings increase from 28 to 32.
The weight glass per serving is reduced from 7.69g (215.3 ÷ 28) to
5.36g (171.4 ÷ 32): a 30% reduction.
Steel cap: Change the cap to an Eco-cap which is the lightest twist-off
cap option available. New weight of cap 7.7g.
Label: The existing label covers 95% of the jar circumference. A label
redesign would allow the same information to be printed on a smaller
label. Also reducing the thickness of paper will provide further weight
savings. The new weight of the label is 0.8g.
Product concentration – number of servings
The amount of product can be increased from 400g to 454g with the
use of a lighter glass jar with larger capacity. The number of servings is
increased from 28 to 32.
Secondary packaging or palletisation
Corrugated board tray: A change to best in class E flute reduce the
tray weight from 28.3g to 23.2g, saving 5.1g will give a 8% weight
reduction to.
Shrink film: The weight of LDPE shrink film can be reduced by use of
thinner gauge film (often combined with better performance polymers
and film structure), and minimising any film overlap on the base join.
No weight reduction opportunity found on this pack.
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Case label: The label is the minimum size required for the printed
information. Direct printing of information directly onto tray is not
possible as it may be obscured by shrink film.
Changes in pack size or shape may allow weight reduction in secondary
packaging and an increase in the number of consumer units on a pallet.
Currently there are 30 cases per layer and pallet is stacked 7 layers high
with a total of 1260 consumer units per pallet. Options considered
were:
 Change from six jars per tray to twelve per tray. Since blackcurrant
jam does not have high volume sales, the shelf facing will be small,
so larger pack unlikely to be acceptable to retailers. Small carbon
saving in tray weight could be partly negated by requirement for
increased gauge shrink film. The number of consumer unit remains
unchanged with this new configuration.
 Increase in number of cases per layer. There are currently 17 cases
per layer, with an efficiency of 99.81% - a good result. Thus no
further changes in the number of cases are recommended.
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Reduced sugar blackcurrant jam
Calculation of pallet efficiency
Inputs
Calculation
Case size
225mm x
171mm
Number of cases per
layer
Pallet size
Pallet size less 10mm at
edge to protect cases
Pallet efficiency
Maximum number of
cases possible per layer
Area
30
1200mm x
1000mm
38,475 mm2
1.15 m2
30 x 38,475 ÷ 106
1.2m2
1180mm x
980mm
1.1564m2
1.10 ÷ 1.1564
%
99.81.25 %
1,154,000 ÷
64,790
30.06 versus
30 actual
Figures of less than 90% efficiency are considered poor. The
maximum number of cases per layer is a quick assessment of the of
the case layout efficiency. Case layout may be optimised using
specialised software.
Glass colour and recycled content
Due to demand and availability of different glass colours, the recycled
content of glass is Green (72.4%), Flint or clear (33.4%) and Amber
28.1%. Since glass jars may be used for a variety of jams in which
Reduced sugar blackcurrant jam
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appearance is an important marketing factor, no change from flint glass
was acceptable.
If a packaging supplier is able to offer a higher recycled content for Flint
glass, this may be used to calculate carbon savings.
Other materials – recycled content and/or
recycling rate
If higher recycled content is available for other materials (apart from
paper and board) this may be used to calculate carbon savings.
There is currently no facility within the WRAP Carbon Ready Reckoner to
calculate the effect of increased recycling rate, such as glass jars with a
returned deposit value.
Other changes
Other beneficial changes that could be made to this pack are:
 change corrugated board tray outer layer from bleached paper to
natural;
 reduce to amount of ink on tray coverage from 40% to 20% or less;
and
 change case label to linerless label and eliminate silicone-coated
paper backing.
Reduced sugar blackcurrant jam
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WRAP Carbon Ready Reckoner –
Data entry
This section describes the process used to enter the previous
figures from existing and new packing components and
calculation of the relative CO2eq impact.
Logging in
The WRAP Carbon Ready Reckoner was accessed via:
http://www.wrap.org.uk/content/carbon-ready-reckoner-registrationform and the correct Username and Password entered.
A new project was created by clicking on the green button “CREATE A
NEW PROJECT”.
Definition
A description of the pack being examined was entered, with sufficient
information to ensure it is not confused with any other project.
Under “Which aspects of the packaged product are being changed?” the
boxes relating to packaging weight, product concentration/servings and
secondary packaging or palletisation are selected.
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The product measurement unit, weight, servings per pack, and number
of packs per annum were entered under the “Existing” column as shown
above. By changing to a best in class glass jar, the new pack can hold
up to 454g of jam which provides 32 servings, and so „454‟ and „32‟
have been entered under the “New” column.
Click green “SAVE” button then move to next page: Consumer Unit.
Consumer unit
This page allows the entry of consumer unit packaging components:
glass jar; cap with liner; label. Click “ADD NEW COMPONENT” button.
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Enter a description of each component, current material (from drop
down list); current weight, and new weight (as applicable) for each
component as shown:
When each component entry complete, click the green “SAVE” button.
It is always possible to edit or delete components later.
The figure for Current Recycled Content is automatically generated, but
may be changed, except for paper and board components.
When complete each entry may be viewed with the CO2eq figures
already calculated.
Even if there is no change in weight, all components should be included
as they contribute to the final pack weight which affects the carbon
impact of distribution.
Component entries may be deleted D or edited E using the small buttons
on the right hand side.
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As the jars of jam have secondary packaging, the “Yes” radio button has
been selected. Click “Secondary>>” to move to the next page. If you
wish to alter your selections it is possible to navigate by these buttons or
via the top or bottom navigation bars.
Secondary packaging
There are six jars in a shrink wrap case, so 6 is entered into the
“Existing” box. As this is not being changed, 6 is entered into the “New”
box.
Components are added in the same way as before, using the green
“ADD A NEW COMPONENT” button. The weights of the existing and
new trays are entered. The weights of both existing and new shrink-film
and case label are the same, but must be entered.
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Press the green “SAVE” button and then “Palletisation” to move to the
next page.
Palletisation
This page allows the entry of changes in palletisation and calculates the
carbon savings from any reduction in pallet numbers and the reduction
in packaging component weights.
The type of vehicle is selected from the drop-down box Rigid (>17t) and
the one-way distance entered as 150km.
The calculated number of consumer packs per pallet is entered as 1260
and number of pallets per vehicle is 16 for the Existing pack. As there is
no change, the same entries are made for the New Pack.
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Clicking the green “SAVE” button will save these entries and calculate
the carbon impact and savings in the yellow boxes.
The reduction in the number of vehicle journeys needed come from the
increase in number of servings per pack.
To view the final results, click on the “Results” button on the right hand
side to progress to the next page.
Results
This page shows the results of the calculations, and shows a 29.00%
reduction in weight CO2eq.
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In this example, we have made changes to the packaging weight,
product concentration and secondary packaging. The tick boxes above
are a check of the improvements included in the calculations.
The results below show the change in CO2eq between the Existing and
New packs, and demonstrate in a pie chart the relative impact of
different packaging components and transit.
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Note that the weight of the packaging is now expressed in weight/CU
(consumer unit or primary pack). Clicking on the “Show difference” on
the top right hand side of the Consumer Unit table will show the
calculated savings.
Reduced sugar blackcurrant jam
Before implementing any packaging change you will need to
ensure that changes will not cause adverse effects during
filling, processing and distribution. Pack image is always an
important marketing consideration.
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