Services > D-Value
Salesworth has been conducting D-value studies for our customers' products through SGM Biotech, USA (Mesa Labs, Bozeman Manufacturing Facility, USA) and we have determined D-values successfully for over 100 products and devices. Most importantly, we provide technical support throughout the process.


To design an OPTIMAL and appropriate lethality cycle using an empirically derived D-value for a specific pharmaceutical product.


Many new products / medical devices / media are heat labile and a typical Overkill Cycle is NOT suitable. A product based D-value gives a resistance value that depends exclusively on the interaction of the most resistant spores and that product.


The product is sent to SGM Biotech, USA in a sealed container. A typical process flow for a D-value study is as follows:

Product is inoculated with widely recognized most resistant spores for that sterilization
o process (e.g. Geobacillus stearothermophilus for steam at 121°C). Ampoules are prepared using a Cozzoli machine.
Graded exposures are conducted for these ampoules in a BIER vessel.
Using the Survivor Curve Method, based on ISO guidelines, the D value is calculated for that product.
Detailed reports with raw data are provided to the customer after the study is completed.


Salesworth provides extensive technical support to our customers in using the determined D-value to design a lethality cycle for validations. The choice and use of appropriate BIs for validations and routine monitoring is also determined and discussed in detail.

Please contact us for pricing and procedure to get started on a D-value study for your product or medical device.

You can reach us at :
Phone : 0091 80 22191800
E-mail :