Transpiration Control Technology
The cornerstone of the scientific community is accuracy. That’s why Inorganic Ventures has always been committed to producing the industry’s most exact Certified Reference Materials (CRM's).
But our control…and the control of every standard manufacturer…ends shortly after a standard is calibrated and packaged. TCT packaging significantly extends the shelf-life of all our CRM's by up to 4 years.
Transpiration has been described in the scientific literature for many years since (e.g. Schumacher, 1958), and national metrological institutes such as NIST (National Institute of Standards and Technology) began discussing transpiration on Certificates of Analysis in the 1990s. Additionally, the packaging industry (among others) has published data regarding transpiration, though the effect is typically referred to as moisture vapor transmission rate (MVTR) or water vapor transmission rate (WVTR). Transpiration results in an increase in the concentration of the CRM.
With TCT, concerns about shipping or storage conditions are eliminated, as transpiration is no longer an issue, which reduces costs & increases efficiencies by removing the need to constantly restock & revalidate CRMs.
With TCT, customers control the expiration date for all Stock & Custom CRM's
Stock CRM's, protected by TCT, retain their scientific integrity for up to four years from the date of manufacture. The product is protected for up to three years in the TCT package and then up to an additional year after the product has been removed from the package.
Custom CRM's, protected by TCT, are delivered to you with 4 year's shelf-life - 3 years when stored in the TCT package plus 1 year once the package is opened.
The expiration of Inorganic Ventures certified reference materials (CRMs) packaged using Transpiration Control Technology (TCT) is determined by specific information provided in Section 11.0 of the product Certificate of Analysis:
Certification Issue Date – the date upon which the product is certified
Lot Expiration Date – the date upon which the entire lot (batch) of product expires. This expiration date is not specific to a container, location, or storage condition, and applies equally to all of the product currently in existence.
Period of Validity – this defines the expiration of specific containers of the product. Therefore, different containers of the same lot (batch) of product can have unique Periods of Validity.
The Certification Issue Date and Lot Expiration Date cannot vary; these dates are assigned by Inorganic Ventures when the product is certified. In contrast, the Period of Validity depends upon when the sealed TCT package is first opened, and is therefore defined by the actions of the product user.
The policy outlined above addresses the three factors that can affect the certified values of a CRM: chemical stability, transpiration, and human errors associated with laboratory use. Chemical stability is demonstrated through long term stability studies, and is represented, at a minimum, by the period of time defined by the Certification Issue Date and the Lot Expiration Date. Transpiration is controlled by the TCT packaging, and does not affect the CRM or its expiration as long as the product remains in the sealed TCT package. The Period of Validity primarily addresses the human error factor and to a lesser extent the transpiration that will occur after opening the sealed TCT package. Once the sealed TCT package is opened, the product in that specific container is valid for one year (i.e., the Period of Validity) when stored and used under normal laboratory conditions.
Supplementary information regarding both TCT and the expiration of CRMs is available on our website (http://inorganicventures.com/tct and https://www.inorganicventures.com/shelf-life-vs-expiration-date-chemical-standard), and technical assistance is always available for additional questions or concerns.