Week 10 Process, Environment & Equipment Control
Hi Everyone!
WEIGHT, QUANTITY & VOLUME CONTROL
The weight, volume and quantity controls are a legal
requirement, and trading standards may visit to check you are carrying weight
checks out correctly for your products legality.
Having a good set of trading standard scales is also
important, so we will chat about this too.
Scales calibration and verification will also be covered
in this section.
What’s coming next…
|
PROCESS,
ENVIRONMENT & EQUIPMENT CONTROL Week 11 –
Environmental Sampling Plan - Swabbing Regimes & Water Testing |
Please see the attached file for getting SALSA sussed…
Weight, Quantity & Volume – what do you need to
show your SALSA auditor?
Weight, Quantity & Volume
Procedure
Scales Calibration Certificate
Scales Verification Record
Weight, Volume or Quantity
Check Records
Weight, Quantity &
Volume Procedure
In this procedure it’s a great
idea to set out what you are going to do, as a company, to control the product
weight / volume.
Include the following:
Trading Standards scales are
used. They are calibrated annually by a UKAS accredited scales calibration
company, and the certificate is kept on file.
Scales are verified on site on
a weekly basis (this can be more or less frequent depending on risk, but at
least weekly is advised). All staff are trained how to carry out scales
verification who carry out the task. The weights used to carry out scales
verification checks are similar to the product or raw material weights being
measured.
Weight checks of the finished
product are completed on every batch of product made. The checks are
documented on production records to evidence the checks have been carried out.
The frequency and quantity of products weighed are in line with the
legislation.
Legislation
This is the legislation to check
to make sure you get it right for your product:
There is different legislation,
minimum weight and average weight
Minimum Weight
This is where
the e is not used.
It simply means that every one of
your products has to be AT LEAST the weight you display on the pack.
There is no lower weight
tolerance.
The weight can be above what is
stated on pack, but as long as the consumer is getting at least the weight
which is displayed on the pack – it is legal.
Of course, you do not want a great
deal of overweight products, as this means you are giving your product away.
The more you give away the less profit you are making.
And also, if your product is
heavier, it can affect the nutritional values if considerably overweight,
therefore your monitoring activities of weight is very useful.
The frequency of weight checks
will be dependent on the length of your packing runs, however for short runs of
an hour or less, I would suggest start, middle and end of run is sufficient. 3 to
5 products per weight check.
If your packing runs are longer,
have a rule such as start and end of run, then every hour, or half an hour
in-between. 3 to 5 products per weight check.
All of the weights must be
recorded on your production or packing records.
If it isn’t written down, it
hasn’t been done!
Quantity Checks
If you are selling a product per
quantity in a pack, then you must complete quantity checks and record them too.
Take a number of packs, usually 3 to 5 packs, at the start, middle and end of
the packing run, and count that the right quantity is within the pack. Record it.
Average Weight
This is where the e is used.
Where finished product labelling
indicates average weight or volume with the e symbol, there are a set of rules that must be
adhered to, these are called the 3 packers rules:
The Three Packers Rules are:
1.
The average weight of the batch must be
not less than the nominal weight.
This means that some of the batch can be over some can
be under, but the average weight of all packs in that batch is equal the weight
stated on pack.
2.
The proportion of packs that are less
than the declared weight by the ‘tolerable negative error’ (TNE) should be no
more than 2.5% of the batch (-T1).
This means that no less than 2.5% of the whole batch can
be less than your -T1
3.
There must not be any packs that are
twice the TNE or less (-T2).
Any weight checks completed showing a -T2 tolerance or
under, cannot sold as they are not legal.
|
Tolerable
negative error |
||
|
Nominal
quantity in g and ml |
As a % of nominal quantity |
g or ml |
|
5 to 50 |
9 |
- |
|
from 50 to 100 |
- |
4.5 |
|
from 100 to 200 |
4.5 |
- |
|
from 200 to 300 |
- |
9 |
|
from 300 to 500 |
3 |
- |
|
from 500 to 1,000 |
- |
15 |
|
from 1,000 to 10,000 |
1.5 |
- |
|
from 10,000 to 15,000 |
- |
150 |
|
above 15,000 |
1 |
- |
+T1 is then calculated by adding
the % or g/ml to the nominal weight or volume.
The –T2 and +T2 is then calculated
by taking away or adding twice (x2) the % or g/ml.
|
-T2 |
-T1 |
Target / Nominal Weight |
+T1 |
+T2 |
|
232g |
241g |
250g |
259g |
268g |
|
-T2 |
-T1 |
Target / Nominal Weight |
+T1 |
+T2 |
|
376g |
388g |
400g |
412g |
424g |
If you need to weigh liquids, such
as if you are bottling a soft drink or cordial, then you need to calculate the
weight depending on the volume and density of the liquid. To calculate this,
you need to multiply the density by the volume
Density x Volume = Weight
To find out the density of your
drinks, a hydrometer can be used.
https://www.brannan.co.uk/scientific/hydrometers
It’s a good idea to have a
hydrometer to measure each products density and complete your calculations.
Document these, so you know what the weights should be.
A simple way to cross check, is to
ensure you also know the empty weight of your packaging, i.e., the bottle, lid,
label and tamper seal if you are using them. Carry out the physical task of filling
the bottle to the correct accurate volume, then weigh it. The total weight
should be equal to the packaging weight and the product weight calculation
(density x volume).
This is the weight that the staff
will check, when the weight checks are being carried out, so make sure it is
documented on the training instructions and records they use. Keep your
calculations for use when showing trading standards or auditors.
Do this for each different product
as the density can be different for each one.
Once you have your finished
product weights, you need to determine the frequency of the weight checks…..
Weight Check Frequencies
The legislation states that the
sampling rate must be at least 50 packs per 10,000 packs produced, the minimum
time to produce 10,000 packs is 1 hour and the maximum allowed is 1 day.
To calculate the number of samples
that must be taken per hour or per run, the following must be calculated:
1.
How many units are produced in 1 day? If it is less than 10,000 then the sampling
rate must be 50 samples per day.
2.
If the number of units are more than 10,000
units in 1 day, then calculate the hourly output. Then divide the hourly output by 10,000. The
result is the frequency in hours, to which 50 samples must be taken.
For example, if the output is 20,000
units per hour, the calculation would be 20,000/10,000 = 2 hours. So, 50 samples per 2 hours.
Many of you might not be at the
capacity where you are producing so many units just yet. So, trying to achieve
this may seem quite difficult. However, if you weigh 5 products per weight
check, you could achieve this more easily than you think.
Out of Range Weight Checks
If, once you have completed the
packing run, and the average weight calculation is not the same or greater than
the nominal weight, then it must be corrected.
Any product which is -T2 or less,
must be put to waste. If more than one product is -T1 or less, then a larger
sample of products must be weighed to check the rest of the batch. Any more
than 1 -T1, must be put to waste.
If you are able to rework your
product at this stage, the -T1’s and -T2’s can be reworked.
For minimum weights, any product
not reaching the minimum weight on pack must be put to waste (or reworked if
possible).
Purchasing Scales
Only one set of scales needs to be
a Trading Standard set. This is the set that you would use to weigh your
finished product. They have to be the most accurate scales, as you are weighing
the legal weight of your product!
The scales have EC or M approval
stamps on them. When purchasing always make sure they are trade approved.
Always keep the calibration
certificate on file, which will have been delivered with the scales. Then on an
annual basis, the scales will need to be calibrated again by an external
calibration company, to make sure they are validated as weighing the correct
weights, and if not, adjusted back to accuracy.
Weight Check Record
Example of a weigh check record.
You could take this and alter it for use, depending on which type of check you
are carrying out (average/minimum/quantity)
|
AVERAGE / MINIMUM WEIGHT / QUANTITY CHECKS To be completed at the start and end of the run,
plus every 30 minutes in between. For
weight – record the actual weight. For minimum weight, just record in the
target weight column |
|||||||||||||||||
|
Time |
-T2 Weight
Xg |
-T1 Weight
Xg |
Target Weight
Xg |
+T1 Weight
Xg |
+T2 Weight
Xg |
QUANTITY |
INITIAL |
||||||||||
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Scales Verification
You need to make sure that on a
set frequency, usually weekly, you are checking that your scales are working
correctly, and weighing the correct weights.
To do this, you need a set of
weights similar to the product or raw material weights for the set of scales
being checked. You can get trading standard weights which is best practice.
When checking scales, best
practice is to take the weight, place it in each corner of the scales, then the
centre of the scales. This is to make sure whichever location you place an item
on the scales, it is always reading the correct weight.
4 1 3 2 5
Record all of the weight checks taken
for the scales verification.
If you need assistance, please
feel free to contact me!
On that note, that is the end of
this section. Please do not hesitate to ask any questions.
Be careful and stay safe!
Ruth
Ruthshawconsultingltd@gmail.com
07732
966 836
Comments
Post a Comment