Carbon Ready Reckoner – Worked Example
Organic whole milk
This worked example shows how the WRAP Carbon
Ready Reckoner can be used to provide insight into
the carbon footprint of 2 pints of milk packed in an
HDPE bottle
Date: October 2013
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Organic whole milk
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 four packaging components:
 HDPE plastic bottle;
 HDPE cap with ribs on the side for extra grip;
 cap internal seal with top easy open tab; and
 plastic shrink sleeve label with full colour print.
The WRAP Carbon Ready Reckoner does not assess minor materials so
the plastic top tab is not included as a separate item.
To calculate the impact of changes, the number of consumer units
produced per annum is required. In this example, three million bottles
of milk are sold per annum. If this pack format were used for a range of
milk, then the total number of consumer units produced in the range
could be included in the assessment.
This bottle contains two pints (1.136litres) of milk which provides five
servings. Before removing the product it was noted that there was
significant head space which could be reduced.
Product information
Information required
Product weight per pack (g or ml)
Servings per pack
Number of packs per year
Existing pack
1136ml
5
3,000,000
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Organic whole milk
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.
Secondary packaging is not normally used for HDPE milk bottles. They
are usually packed directly onto reusable trolleys.
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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Organic whole milk
Consumer unit
 The HDPE bottle, cap, seal and label were relatively light and so
each was calculated from the total weight of a batch of 50
components.
Existing components – consumer unit
Component name
Bottle
Existing material
Current weight (g)
HDPE bottles
26.2
Cap
HDPE rigids (non
bottles)
1.5
Seal
Aluminium
0.2
Label
PE film
0.8
Secondary packaging
There is no secondary packaging associated with this pack.
Palletisation and transport data
In the case of milk, milk trolleys are used instead of pallets. In this
example, it is assumed that a standard milk trolley1 measuring 600mm
by 420mm by 1300mm with four stacking tiers is used.
This data is used to calculate the carbon impact of packaging changes
on transport. The data required is listed next.
1
http://www.she-ltd.co.uk/product/139
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Organic whole milk
Palletisation and transport data
Information required
Type of vehicle used for delivery
Average one-way distance to
retailer or RDC (km)
Number of consumer units / case
Existing
Rigid truck used most often –
capacity up to 17tonnes
150km
n/a
Number of bottles per layer
35 bottles per layer
(7 by 5)
Number of layers per trolley
4
Number of consumer units per
trolley
140
(35 bottles x 4 layers)
Number of trolleys per vehicle
40
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
trolleys of this product that this vehicle will carry is 40.
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Organic whole milk
Pack improvements
The WRAP Carbon Ready Reckoner will calculate carbon savings from
various pack improvements. Each is considered as it applies to this
bottle of milk. This pack was compared with other two pint bottles of
milk 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).
Packaging weight
Bottle: The best in class milk bottle is currently the Infini2 bottle (by
Nampak) which is 6.2g (23.4%) lighter at 20.0g.
Cap: Further light-weighting could be achieved by reducing the profile
of the cap. This will provide a small reduction of 0.1g (6.7%) to 1.4g.
Seal: Top tab on the seal could be eliminated and replaced by a side
tab; reducing the weight by 0.1g (50%) to 0.1g.
2
http://infinibottle.com/fact-figures/
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Organic whole milk
Labels: There were no opportunities for improvement on the label. A
smaller self-adhesive paper label may have less carbon impact than a
plastic sleeve, but once the silicone-backed paper waste is included, this
is not a better option.
Product concentration – number of servings
This product is sold as a fresh produce and any concentration would
change the nature of the product and likely to be unacceptable to the
consumers.
Secondary packaging or palletisation
There is no secondary packaging associated with this pack. No change
in milk trolleys is proposed.
Glass colour and recycled content
There is no glass content in this pack.
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.
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Organic whole milk
Other changes
No other beneficial changes to this pack were identified.
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”.
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Organic whole milk
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
box relating to packaging weight is selected.
The product measurement unit, weight, servings per pack, and number
of packs per annum were entered under the “Existing” column as shown
above.
Click green “SAVE” button then move to next page: Consumer unit.
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Organic whole milk
Consumer unit
This page allows the entry of consumer unit packaging components:
bottle; cap; seal and label. Click “ADD NEW COMPONENT” button.
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.
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Organic whole milk
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.
As the milk bottles have no secondary packaging, the “No” radio has
been button selected. Click “Palletisation>>” 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
As “secondary packaging or palletisation” box was not checked at the
project definition page, this section has been excluded.
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Organic whole milk
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 140
and number of pallets per vehicle is 40 for the Existing pack. As there is
no change, the same entries are made for the New Pack.
Clicking the green “SAVE” button will save these entries and calculate
the carbon impact and savings in the yellow boxes.
Organic whole milk
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Organic whole milk
The weight savings seen here are from the light weighting of the
primary packaging.
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 14.11%
reduction in weight CO2eq.
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Organic whole milk
In this example, we have made changes to the packaging weight, 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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Organic whole milk
Note that the weights of the secondary 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.
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Organic whole milk
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.
While we have tried to make sure this worked example is accurate, we cannot accept responsibility or be held legally
responsible for any loss or damage arising out of or in connection with this information being inaccurate, incomplete or
misleading. This material is copyrighted. You can copy it free of charge as long as the material is accurate and not used in a
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on our website at www.wrap.org.uk
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