All Member Forum

Hi everyone,

I'm taking a critical look at our company's temp & humidity testing, and it seems extreme to me, and not representative of an actual shipment. The test is 140 hours (5.8 days).  The temp cycles between -40 and 70, and the relative humidity cycles between 10% & 95%. I don't think this would be a common scenario to constantly go back and forth between these temps/humidities out in the world.

 I was looking at the ISTA 2A/3A Conditioning tests (they are the same) and looking at possibly using the "Hot, Humid" test which is 72 hours and stays at a steady temp of 38C (100F) and 85%RH. I was curious what other standards other packaging professionals use. We ship globally using all modes of transportation. What conditioning tests do you use at your company? Thanks.

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Georgia Rockwell
Packaging Engineer Leader
GE Healthcare
Waukesha WI
(262) 282-8349
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Hi Georgia. I run a package testing lab at STERIS and do lots of environmental conditioning for our customers. Most follow ASTM D4322. The most common temp/humidity conditions within D4332 that are followed are very similar to ISTA 3A. Extreme Cold: -30C, Tropical: 40C 90%RH, and Desert: 60C 15%RH. D4332 recommends 72 hours at each condition or the amount of time it takes for the packages to equilibrate. These conditions are pretty extreme, but I don't think they're outside of what could be seen by your product being shipped at different times of the year in different parts of the world. Though 72 hours is not very realistic in my opinion. They are meant to be worst case though. 

An alternative you could look at is ASTM F2825. This standard is specific for single parcel delivery, overnight or two-day delivery though. It uses less extreme conditions and for shorter durations. -20C, 50C 25%RH, and 30C 90%RH for 4 hours each. 

Ultimately you want to use conditions that are realistic to what your product could see. Of course the same product isn't likely to see extreme cold and high temp/humidity conditions during real shipping, but different shipments could depending on where in the world it's going and what time of year. Most people just combine it all into one cycling of extremes for simplicity's sake. For what it's worth, we almost never see failures of packaging from this conditioning cycle. If we do it's corrugate that doesn't hold up to the humidity very well. 

Hope this helps!

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Nate Wilhelm
STERIS
Brooklyn Park MN
17633151216
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Hi,

The kraft paper industry uses the test conditions per ISO 554 – 1976 (Temp of 23 ± 1 °C / RH of 50 ± 2 %) which requires the samples to be conditioned for at least 24 hours. 

Hope this helps.

Indrajit Sen

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Indrajit Sen
Business Development Manager
Canadian Kraft Paper Industries Ltd.
WEST KELOWNA BC, Canada
Cell: 204 627 9106
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Original Message:
Sent: 06-10-2024 08:27 AM
From: Nate Wilhelm
Subject: Temp & Humidity Testing

Hi Georgia. I run a package testing lab at STERIS and do lots of environmental conditioning for our customers. Most follow ASTM D4322. The most common temp/humidity conditions within D4332 that are followed are very similar to ISTA 3A. Extreme Cold: -30C, Tropical: 40C 90%RH, and Desert: 60C 15%RH. D4332 recommends 72 hours at each condition or the amount of time it takes for the packages to equilibrate. These conditions are pretty extreme, but I don't think they're outside of what could be seen by your product being shipped at different times of the year in different parts of the world. Though 72 hours is not very realistic in my opinion. They are meant to be worst case though. 

An alternative you could look at is ASTM F2825. This standard is specific for single parcel delivery, overnight or two-day delivery though. It uses less extreme conditions and for shorter durations. -20C, 50C 25%RH, and 30C 90%RH for 4 hours each. 

Ultimately you want to use conditions that are realistic to what your product could see. Of course the same product isn't likely to see extreme cold and high temp/humidity conditions during real shipping, but different shipments could depending on where in the world it's going and what time of year. Most people just combine it all into one cycling of extremes for simplicity's sake. For what it's worth, we almost never see failures of packaging from this conditioning cycle. If we do it's corrugate that doesn't hold up to the humidity very well. 

Hope this helps!

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Nate Wilhelm
STERIS
Brooklyn Park MN
17633151216
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Hi Georgia,

It would be helpful to know if the tests have caused lab failures you never see in the field, or, conversely, do the tests not replicate known, consistent field failures? If either of those things occur, then clearly you need new tests. 

On the other hand, if you pass the tests and have no field failures due to environmental conditions, then it may mean your tests are excessive. 

Unfortunately, lab tests may miss the real reasons behind field failures due to temperature and humidity.  Here are 2 examples:

1. A client had excess moisture inside of ocean containers from Asia to the US and Europe, leading to lots of condensation on the inside of the metal ocean container and "raining" down onto boxes, causing moisture damage to nicely printed, consumer electronics boxes.  They had tested the boxes through similar conditions to yours and found no issues, but the US lab tests missed two critical things: the actual pallets used from Asia, and the condensation that occurs on the inside of ocean containers when moving from hot/humid to cold climates.  The root cause of this failure was wood pallets stored outdoors in places like Singapore, Malaysia and southern China, often subjected to rain. and then releasing that moisture into the ocean container.  Moving this company off of wood pallets and onto plastic slip sheets resolved the issue.  This was a case where the lab tests missed using actual, real life components (wet pallets), along with not replicating the condensation that can occur inside of ocean containers.
2. A client shipped boxed products from India to New Jersey via ocean.  Hundreds of thousands of boxes had been loaded during monsoon season (extremely hot and humid) and landed in New Jersey during a very cold fall and winter.  Tremendous amounts of condensation were on the walls of ocean containers for one box sku, whereas other containers with a different sku, loaded at the same time, had absolutely no condensation.  Though it was the same box maker in India, it turned out the box moisture content was higher (14%) in the high condensation load vs only 9% for the other sku.  Also, the problem box was made of 100% recycled content, which holds much more moisture due to the many broken fibers.  We also measured the desiccant packs hanging in the various ocean containers and confirmed they were completely full in the problematic loads and not maxed out in the non-problematic loads.  The high moisture boxes did not collapse in transit, but they did get soft and wet and mold grew on the inside of most of these boxes.  When the problematic box was compression tested to standard conditions, it showed exceptional strength, but the company hadn't placed a maximum moisture content spec on the drawings.  Simply moving to lower moisture content boxes resolved the issue, though we also decided to increase the amounts of desiccant in each ocean container as extra insurance. 

Temperature and humidity cycles occur in all distribution systems.  Cycling tests, and real life observation, show boxes degrade more with cycling than with steady state tests.  I highly recommend direct field observations to better understand if your lab tests are replicating consistent failures found in the field, and/or may be overly harsh for the conditions observed.

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Kevin Howard
Consultant
Packnomics LLC
Portland, OR
cell: 360-606-0235
desk: 360-828-8822
kevin.howard@packnomics.com
www.packnomics.com
www.linkedin.com/in/kevin7howard
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