Defining Test Practices
An ASTM standard for climatic stress testing of small parcels is approved.
ASTM committees have recently focused on testing packages’ ability to withstand shipping environmental hazards, and evaluating new methods for testing sterile barrier system integrity.
After recent completion of balloting in ASTM International Committee F02 on Flexible Barrier Packaging, ASTM’s committee on standards approved in December ASTM F 2825-10, Standard Practice For Climatic Stressing of Packaging Systems For Single Parcel Delivery.
The standard describes climatic stress testing to determine the ability of a packaging system to withstand a range of climatic stresses it may be exposed to during distribution, handling, and storage throughout the world, when exposed to single parcel overnight or two-day delivery systems. “This addresses a question we have always struggled with:
What are the appropriate temperatures and humidity levels and for what durations should samples be subject to (in order to) duplicate what the package experiences in the real world,” says Spartan Design Group’s Curt Larsen, task group co-chair of subcommittee F02.50, which developed the standard (www.
“People were doing things that were way off the map,” such as exposing packaging to extremes of –50° C temperature for 72 hours, and 50° C at 95% relative humidity (RH) for 72 hours. “There is no place in the world these conditions exist, much less for 72 hours. The whole distribution cycle is only 24 to 48 hours, not six to nine days,” Larsen says.
“At that extreme, a film with water-based tie layers often starts to come apart. You begin to see test-induced anomalies that would never happen in the real world,” he adds.
F2825-10 defines three climatic stress conditions that are based on industry experience, global climate data, and typical durations that a package system might spend in a single parcel delivery system.
Cold condition is –20° C, with unspecified RH, hot/dry condition at 50° C at 25% RH, and warm/humid conditions at 30° C at 90% RH. Exposure time for each temperature is 4 hours.
F2825-10 exposures could be performed before or after simulated distribution stressing following standards such as ASTM D4169 Standard Practice For Performing Testing of Shipping Containers and Systems, Larsen says.
After stressing packaging following F2825-10, the engineer is evaluating the adequacy of the whole packaging system. This includes determining whether the label is readable and remains adhered to the package, the protective packaging is intact, the tape remains sealed, the sterile barrier has not been compromised, and the device(s) are undamaged, Larsen says.
“Some customers will only test the sterile barrier system; that is just accounting for a part of the packaging system. Your design performance testing is on a packaging system, not just the sterile barrier system,” he adds.
ASTM subcommittee F02.40 is completing a revision of F1929 Standard Test Method For Detecting Leaks In Porous Medical Packaging by Dye Penetration. The revision defines alternative external “edge dip” and “eye dropper” methods as better-performing and less messy alternatives to dye injection for detecting seal leaks.
Also, the subcommittee is developing a proposed method for Detecting Leaks in Nonporous Packaging or Flexible Barrier Materials by Dye Penetration (WK25128). The method will define procedures for detecting and locating channels in package edge seals, and for detecting and locating leaks (through holes) in a flat sheet, says Dhuanne Dodrill, president of Rollprint Packaging Products (www.rollprint.com) and chairman of F02.40.
“In order to improve the sensitivity of the method, the dye penetrant solution has significantly more surfactant—six times more—than the dye penetrant solution used in F1929.
“An interlaboratory study will be underway shortly in order to develop a precision and bias statement. Samples for this study are currently being prepared, and the results of the study will be reported at the April 2011 F02 Committee meeting in Anaheim,” Dodrill says.
FDA has recently recognized D4169-09 as a consensus standard and has added the standard to its approved list of recognized standards, says Patrick Nolan, president, DDL Inc. (www.
testedandproven.com). The standard updates the FDA-recognized D4169-05 with an updated bridge impact test added to the test sequence for long corrugated shippers and a concentrated impact test for containers with a burst strength below 275 lb per sq in. or that withstand force less than 44 lb per sq in.
ASTM subcommittee D10.21 task groups are pursuing additional revisions, including a review of vibration data to confirm existing test intensities and if new profiles should be developed, Nolan says.
“No work has been done on test intensity levels for D4169, but there are several task groups formed to evaluate, review published literature and data, and work on bringing the test standard up to date with current industry practice,” he says.
Standard F2825-10 provides additional guidance for evaluating the impact of climatic conditions on packaging. “Up until the publishing of the new ASTM standard F2825-10,
DDL has used a sequence of conditions derived from the ISTA 2A procedure. These conditions have simulated the extremes that might occur in real life. Ever since the revision of ISO 11607 whereby it was deemed that environmental concerns and dynamic performance should be considered separately, we have used the ISTA 2A sequence to evaluate packages to temperature and humidity extremes. The new ASTM standard provides additional guidance and optional testing for environmental extremes,” Nolan says.
Advanced Test Concepts Inc. (atcinc.net) is pursuing an ASTM standard using its mass extraction technology for detecting defects in sterile closure systems. The method is an alternative to pressure decay or helium mass spectrometry testing for package and seal integrity. The company’s Micro-Flow technology provides comparable sensitivity to helium tracer gas methods, with advantages over that technology. Helium gas testing methods that use destructive probes or cumbersome “bombardment” technique are avoided, says Hemi Sagi, engineering director.
In the leak flow measurement solution, ATS Intelligent Gas Leak Sensors directly measure the amount of gas pulled out of a package placed under vacuum in a test chamber. “We measure true microgram or microliter per minute, testing to a much more sensitive level than pressure decay testing. We designed (the system) to detect down to a 0.2 micron defect size because that is the nominal size of filters used in aseptic filling processes,” Sagi says.
“This is the only technology that can test sterile glass containers down to a 1-to-3 micron defect size nondestructively,” Sagi adds. ATS offers production applications for off-line sample testing, and 100% testing of product coming off a line where for example parenteral vial testing can be accomplished in five to eight seconds, Sagi says.