March 3-5, 2009www.healthpack.net

New Applications for Dye Penetration Testing of SBS Packages and Films

Geoff Pavey, Principal EngineerOliver Medical

What will be covered• Intro to Integrity failures/need for dye

testing• ASTM F1929 method• Edge dip method• Pinhole method• Tips and tricks for dye penetration

methods.• Future Work

Integrity testing

Peel strength and burst testing are not integrity tests.

Dye penetrant testing is a an integrity test.It is mainly used to verify, discover, or

determine the compromise in a seal integrity vs. whole package integrity.

Why are we concerned?

Biological or particulate contaminates may enter a sterile barrier system through

leaks.Leaks in seals or other parts of the package

may result from…

Channels

Fractures

Pinholes

Punctures

ASTM F1929• The current test method is ASTM F 1929 dye

penetration.• It has been used for many years for testing seal

integrity of sterile barrier systems.• Round robin tested with a precision & bias

statement with a defined sensitivity, which are helpful for test method validation.

• Recognized as a consensus standard by the FDA. http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfStandards/search.cfm

ASTM F 1929

Method overview1. Inject dye into package.2. Rotate package to expose each side.3. Examining each side through the

transparent substrate for a minimum of 5 seconds.

ASTM F 1929 Dye Penetrant

ASTM F-1929

Summary of issues• Estimating the amount of dye to use for

different size packages.• Wicking causing dye loss and you may

have to inject more dye during the test.• The amount of dye is often over

compensated and wasted.• It is messy and relatively slow.

Edge dip method

• A method that has been around for years. • Some people use it and would like it to become

a standard. • In the ASTM F02 committee on Flexible Barrier

materials under the subcommittee F02.40 Packaging Integrity, we are working to incorporate this as an alternate method in F1929.

• It works using the same dye solution formula.

Edge dip method

Overview1. Select a tray or dish long enough to

accommodate the longest width.2. Fill with enough dye solution to cover

the bottom of the tray,1/8 to 1/4 in. depth.

3. Lower one edge of package into dye making sure entire edge is exposed, approximately 1/16 to 1/8 in.

4. Remove package and inspect for channel for minimum of 5 seconds/ side.

Edge dip method

Edge dip method

Reasons why some prefer edge dip• No needle/ syringe.• Less messy for the tester.• Less dye used and wasted on the

package.• Faster with multiple samples.

Edge dip method

Cutting excess material

Pinhole Method• Another dye penetrant method is the pinhole

technique.• This is not a whole package or a seal integrity

method.• Detecting pin holes, cracks or punctures after

flexing or transportation conditioning in nonporous materials.

• The Gelbo flex test incorporates a similar technique, which is being used as the foundation for this method.

Pinhole method

Overview1. Tape material to flat sheet of white paper.2. Paint the material with dye solution.3. Allow to set for 1 minute.4. Wipe off solution pressing against paper

backing.5. Remove material and count the dye marks on

the backing paper.

Pinhole Method

pinhole method

Summary• Used in a slightly different way than the

previous two methods.• Mostly for R&D evaluation of materials.• This will be a new method separate from

F1929.• It can use the same dye solution formula.

Tips and tricks for dye penetrant testing

• Issues with wicking vs. channels. • 5 and 20 second exposure time

misinterpretation.• Making channels.

Tip #1

Wicking vs. Channel• The dye solution used with ASTM F1929 is very

aggressive and will wick along the fibers of Tyvek® and other porous materials quickly.

• Over time wicking can often appears as partial or full penetration.

• This can be misinterpreted as failure in testing.

3.1 wicking—The migration of a liquid into the body of a fibrous material. This is distinct from a leak as defined in Terminology F 1327.3.3 channel—A small continuous open passage across the width of a package seal through which microorganisms could pass. –ASTM F1929

Wicking vs. Channel

Wicking vs. Channel

• There are significant differences noticed when observing the wicking phenomena vs. penetration through a seal caused by a channel.

• The key is the amount of exposure time.• The capillary action in a channel is much

faster than wicking.

Tip #2

Exposure time• According to ASTM F1929, when

evaluating the seal area, the exposure time is a minimum of 5 and a maximum of 20 seconds .

• 5 seconds is all that is needed because channel penetration is typically noticed within the first few seconds of exposure.

• If exposure is left for full 20 seconds wicking can occur.

Exposure time

• 20 seconds was intended to be the time for the whole package.

• Exposure to the full 20 seconds for one seal can cause severe wicking.

• Results can be up to full seal penetration depending on the seal width.

5 seconds x 4 sides = 20 second

Exposure time

• To better understand wicking and channels, it is helpful to create channels.

• A tungsten wire sealed and pulled though a seal is a good way to evaluate and become educated on the differences.

• This method was used in the evaluation of ASTM F1929 standard.

Tricks

Making channels

ASTM F 1929 – 98 (Reapproved 2004) Standard Test Method for Detecting Seal Leaks in Porous Medical Packaging by Dye Penetration

1. Scope1.1 This test method defines materials and a procedure that will detect and locate a leak equal or greater than a channel formed by a 50 μm (0.002 in.) wire in package edge seals formed between a transparent film and a porous sheet material.

Making channels

Making channels

PVC pipe

Making channels

Sealing

Making channels

Wire removal

Future work • Current dye methods used for detecting channels are for

sterile barrier systems that utilize only one nonporous substrate.

• Non porous method (Two nonporous materials)– New formula of dye solution will be needed. – Because the surface area in nonporous seals have

less surface energy which makes it harder for dye to penetrate.

Future work • Non porous method (Two nonporous materials)

– Preliminary studies had been done by Earl Hackett, the originator of F1929. He was successful using a modification to the amount of surfactant and dye using the current ingredients of F1929.

– This formula will be further explored during the development of this test method.

Conclusion

• Edge dip combined as an alternate method in F1929.

• Creation of a separate test method for pinholes in nonporous substrates.

• Nonporous seal integrity method.

Study participation

• Anyone who has an issue with the current F1929 or other proposed methods,

• is interested in participating in the round robin study(s),

• or has additional tips or tricks to share • Please contact me.

Thank You

Questions?

Geoff PaveyPrincipal EngineerOliver Medical445 Sixth St. N.W.Grand Rapids, MI 49504Direct 616.456.7711 x7213Free 800.253.3893gpavey@olivermedical.com