Acceptable Quality Level (AQL) - Ansell Healthcare Europe

Acceptable Quality Level
(AQL)
Acceptable Quality Level (AQL) is a statistical
measure of the consistency or quality predictor of
manufactured goods. It applies to all batch type
production as a means of ensuring that the process
average meets the standards determined. For
medical products, it is critical that the products are
manufactured to a very high standard at all times.
Surgical and examination gloves are essential barrier
protection items and neither you nor your patients
want to receive a defective glove, however very rarely
this may occur.
What is a homogeneous
batch?
The term homogeneous batch refers to products
that are made in groups and from the exact same
parameters. Gloves, for example, would be from such
a batch if the latex used, production settings and
finishing processes are all exactly the same over that
period. Any alteration at any stage of production is
considered a new batch.
Process average
This term refers to the manufacturing process’
average defect or reject rate. It is critical as an
indicator of the manufacturing quality. To assess this
a set number of gloves taken from the production
line every two minutes are subjected to a full range of
quality tests. The reject rate is the failure percentage
of the product. Production processes are kept in tight
tolerances with the use of control charts.
Control charts
These charts are like recipe cards and they outline all
the parameters for the product being manufactured.
In the case of Ansell gloves, for example, they would
contain the latex and chemical mix for the dip, the
production speed, oven temperatures, type of former
to be used and every parameter including the post
production processing. The tighter the parameters or
tolerances in the control chart, the more consistent
the quality of production will be. Every manufacturing
step of an Ansell glove is documented and mapped
for the production process to ensure our gloves are of
the highest possible standards.
AQL sampling
The table on the reverse is an example of the
arbitrary statistical system for AQL testing. You will
see that inspection levels are set at ‘Level I’. This
is the industry standard for medical grade quality
inspection. Variance to another inspection level e.g.
for machinery, would prescribe different tolerance
levels. The variable parameters are:
1. The lot/batch size.
2. The inspection level – determined by
AS/NZS4079:1997 and 4011:1997 at level I.
3. AQL level determined.
Depending on these points, the number of allowable
failures per sample test will determine the arbitrary
‘yes’ or ‘no’ for that batch to statistically pass the AQL
standard. Failure will mean that the manufacturer has
to inspect every piece of the batch to remove defective
products. This is time consuming and expensive.
Therefore, it is better to build the quality assurance
system into the production process rather than use
inspection at a later stage to remove defects which
occur through inexact production processes.

Curve number Ansell 2 3 World standard 5
AQL 0.065 0.9 1.1 1.5 2.5
Inspection level II II II II II
Lot/batch size 10,000 10,000 10,000 10,000 10,000
Sample size 200 200 200 200 200
Acceptance number 0 3 5 7 10
Curves for Sampling Plan
Probability
of
Acceptance
1.200000
1.000000
0.800000
0.600000
0.400000
0.200000
0.000000
0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 5.5 6 6.5 7 7.5 8 8.5 9 9.5 10 10.5 11 11.5 12
You can see in the graph that the lot (batch) size and
inspection level are the same and only the AQL level
varies. At an AQL of 2.5 the acceptable number of
defects in the sample lot is 10. This falls to 7 allowable
defects at an AQL of 1.5 (the world surgical glove
standard). Ansell’s AQL level of 0.065 (before packaging)
means that a single defect in the sample lot will result
in an AQL failure, resulting in every glove in the
production batch being inspected. As previously stated,
this is time consuming and expensive. Setting an AQL
so low is only possible if the quality and consistency of
production is very high and tightly controlled.
An AQL test is an absolute test i.e. ‘yes’ it passes or
‘no’ the batch cannot be released. However the AQL
test is a direct reflection on the manufacturing process
quality and conformity. Ansell’s AQL level of 0.065
Percent Defective
AQL 0.065 INSP-II AQL 0.9 INSP-II AQL 1.1 INSP-II AQL 1.5 INSP-II AQL 2.5 INSP-II
Ansell Healthcare Europe N.V.
Riverside Business Park, Spey House, Boulevard International 55, B-1070 Brussels, Belgium
Tel. +32 (0) 2 528 74 00 Fax +32 (0) 2 528 74 01 Fax Customer Service +32 (2) 528 74 03
http://www.anselleurope.com E-mail info@eu.ansell.com
(before packaging) ensures that you will consistently be
assured of the highest quality barrier protection. There is
however, as with everything a very rare occasion when a
glove may be defective.
What is the AQL level of the
gloves you are using now?
Ansell’s AQL standards:
• Surgical gloves is 0.065 before packaging
(World standard 1.5).
• Examination gloves 1.5 (World standard 2.5).
Be Ansell Sure.