A “retain” is a set of samples of a particular lot of material that is set aside, and can be assessed or revisited if needed for additional testing.
Sometimes referred to as a “retention sample,” “witness sample” or “reference sample,” a retain is a common practice among pharmaceutical and food product manufacturers, and also utilized by other chemical and material production and packaging industries.
Appli-Tec has maintained a mature and traceable retain process for 10+ years.
Maintaining retain samples at a production facility is similar to an insurance policy: one hopes the retain will not be needed, but it is valuable in a failure or analysis situation.
For example, if it’s believed that an adhesive material is dispensing differently than normal, a customer can request that the retain sample be retested to see how that lot of material is dispensing today.
Retesting the retain sample would demonstrate that the adhesive itself was sound but other factors must be examined to determine the root cause of the failure. (For example, was the shelf life of the material exceeded? Was the material handled improperly? Was the surface preparation insufficient?)
Usually, retain samples are maintained for the duration of the shelf life of the materials, plus one month, and stored in the recommended conditions stated on the certificate of compliance (e.g., in a -40C freezer or at room temperature).
The Appli-Tec retains policy applies to all products with a dated shelf life. This includes precision mixed and frozen syringes, room temperature materials, and two-part kits.
The retains policy does not apply to material that is delivered cured, such as a plastic thermoset backing material.
Retains are your best insurance policy. The benefit is knowing there is recourse if there is some suspicion that the material in question may have experienced an unexpected condition.
For example, imagine a scenario where an electricity outage or mechanical failure led to a freezer whose temperature rose from -60C to 20C for some period of time, and then automatically corrected to -60C.
Operators would pull a syringe from a freezer, and the adhesive would be thicker, maybe even cured, and would not be able to be dispensed. You could call Appli-Tec and we would pull a retain to confirm the viscosity of the adhesive. If our retain is good, you will know that something happened to your freezer.
The downside to retains is that they add cost to the production or packaging facility keeping them. Maintaining retain samples requires meticulous record-keeping and immense storage capabilities. The additional material for the retain sample must be calculated and planned as part of the production process as well.
But like any insurance policy, if you offset these costs to your security and risk reduction, they are often well worth it.
In mission-critical applications, the insurance of retain samples may be a requirement.
In other industries that require lot-to-lot consistency, having your supplier maintain retains can ensure a lower risk supply. Having the peace of mind to know that there is a “backup” to test your material in the case of unexpected conditions or questionable outcomes can be priceless.
Through December 2019, Appli-Tec has maintained retain samples for each lot of material produced.
Starting in January 2020, Appli-Tec will institute a new policy regarding retains. Retain samples will be an additional line item and fee for each material line item.
In the case of an order with multiple delivery dates for a single line item, the charge will be added for each delivery of that line item.