Ambient Profiles

Developing an ambient profile for validation testing can be a difficult task. An ambient profile is a combination of reasonable worst-case temperatures and reasonable worst-case time durations. It is best to have an intimate knowledge of the distribution path for the majority of the shipments in order to develop an accurate temperature profile. An excellent resource for the creation of an ambient temperature profile can be found in the 2002 ISTA 5B standard. This standard discusses the accepted methods for validating shipping configurations and is a valuable source of information. Find it at www.ista.org. It is important to note that developing an ambient profile by theoretically determining the worst case times and temperatures for each step along the package’s journey is not a better way to develop an ambient profile than collecting actual temperature data from shipments. However, collecting ambient data is a time-consuming and expensive project. These steps can help determine a theoretical ambient profile before data has been collected.

Duration

Duration refers to the amount of time the ambient profile is run. The duration of performance for the ambient profile depends heavily on the shipping method used. In most cases, the duration is longer than you might expect when you consider time after the container is packed and time to reach the recipient. For example, the duration for overnight shipments is generally much longer than 18 hours. From the time the package is assembled to the time it is received (and unloaded), the package may experience up to thirty hours in transit. In fact, FedEx officially recommends using 30 hours as an estimate for shipping temperature-sensitive products using FedEx standard overnight service. For example, a package may be assembled at 9am in anticipation of the day’s orders, picked up by the carrier at 3pm, and received by 3pm the next day. It may be delivered before this, but not unpacked and stored at the proper temperature until this time. This is thirty hours and is often used by pharmaceutical companies as the standard for overnight shipments. Similar estimations are used for two-day shipments where it is common to see sixty hours as the required duration. The best way to estimate shipment duration is to theoretically walk through the distribution line and determine reasonable worst-case times for each step. Knowledge of the distribution center, as well as the modes of transportation used, will be key in developing this information. When shipping internationally, it is important to leave adequate time for delays from customs, perhaps up to an extra 48 hours.  contact the carrier for information on the duration of the steps while they are in control of the package.

It is extremely important to understand the difference between performance duration and test duration. For qualification studies, assigning the performance duration at thirty hours for an overnight shipment will assure that the product remains with its temperature requirements for this amount of time. However, it is generally a good practice to test for a longer period of time in order to gain additional information about the temperature stability of the package. Therefore, an overnight shipment may be tested for a total of 48 hours, even if the performance duration is only 30 hours. The test duration is always equal to or greater than the performance duration.

TIP:  To save time and money in lab testing to develop the configuration, test for only the performance duration during development testing. Increase to the full test duration for qualification testing where the majority of the documentation is produced.

Temperatures

Once the distribution path for the package is determined and each segment defined, the next step is to assign temperatures. Determining reasonable extreme temperatures is often a difficult step in developing the ambient profile. For each segment of the trip, determine the reasonable worst-case low (winter) and high (summer) temperature. With these temperatures in place, the ambient profile is assembled and completed. With adequate documentation, the ambient profile is justifiable and defendable for internal and external quality audits. Once again, this method of creating an ambient profile is less defendable than showing actual data from test shipments along your distribution path.

A sample summer and winter ambient profile may look like this:

This would result in the following ambient profiles, when condensed:

Universal vs. Dedicated Configurations

When developing a packing configuration, it is important to decide before testing begins whether the configuration designed should be successful in both the summer and winter ambient profiles, or if a separate configuration will be developed for each ambient profile. A single configuration for both ambient profiles is called a “universal” design. If the configuration is different for the ambient profiles, the design is considered “dedicated”, or “seasonal.”  Of course, there are advantages and disadvantages to each.

Universal Configuration Advantages

• Ease of use – Universal configurations do not change with different seasons of the year, so there is less chance of mistakes and less training required.
• Consistent Packaging – Universal configurations remain consistent year-round and will not require different packaging to be purchased and inventoried for different seasons.
• Quality – A configuration that does not change with the seasons is easy to defend in quality audits, both internal and external, due to the absence of questions about when you change between packouts.

Universal Configuration Disadvantages

• Expense – When developing a universal configuration, the amount of material used will generally be higher. This will require more expensive containers, possibly PUR instead of EPS.
• Weight – A universal design will generally weigh more, increasing shipping fees and the long-term costs of the container.
• Complexity – An increase in packaging material may create a more complex packout configuration. For example, a dedicated winter configuration may only use refrigerated gel packs, but a universal configuration may use frozen and refrigerated gel packs to be successful in the summer ambient profile as well.

Dedicated Configuration Advantages

• Expense – A dedicated configuration will generally use less or cheaper materials. This corresponds to a lower price for packaging materials in most conditions.
• Weight – A dedicated configuration will generally weigh less and will therefore cost less to ship.
• Simplicity – Less packaging may create a simpler packout configuration.

Dedicated Configuration Disadvantages

• Seasonal Changes – Dedicated configurations require a decision about when to switch between the two (or three). This could be a specific date, the temperature of the destination city, the temperature of the shipping city, or some other consistent method. If switching by date is used, the risk is dealing with irregular cold or hot days and whether the pack configuration should be adjusted.
• Inconsistent Packaging – Dedicated configurations may require different packing components or different amounts of packing components for each season. This can cause inventory problems when shipments are sporadic or difficult to predict.

Ultimately, it is the decision by the design group as to which method is best for the company. This can come from a combination of elements including:

1. Company history – Information from the company’s history including previous FDA audits, expensive lost shipments, current SOPs, legacies of past engineers, etc.
2. Product Value – A more valuable product will be more important to over-protect in a universal configuration
3. Quality Department – A strict quality department may require a universal design so that it will be easily defendable during FDA audits. Other, less experienced quality departments may feel more comfortable with a universal configuration until they have more data or experience with FDA audits of cold chain packaging.
   

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