Indivirtus has 6 expert toxicologists (DABT/ERT) who calculate, permitted daily exposure (PDE)/ acceptable daily exposure (ADE) values that is unlikely to cause adverse effect, if an individual is exposed at or below this dose every day for a lifetime. OEL is derived from PDE to find out the exposure limit to which, a person working in the manufacturing area may be exposed everyday (for 8 hours shift) for a lifetime without getting any adverse effect. According to OEL, OEB is decided and safety gears may be set up at the manufacturing site.
As per EMA, PICS and APIC guidelines calculating PDE has become mandatory from 1st April 2018 for all those companies who are exporting to European markets.
https://www.ema.europa.eu/en/setting-health-based-exposure-limits-use-risk-identification-manufacture-different-medicinal
Reference document:
Guideline on setting health based exposure limits for use in risk identification in the manufacture of different medicinal products in shared facilities (PDF/169.13 KB)
https://apic.cefic.org/publications.html
Reference document:
Guidance on aspects of cleaning validation in active pharmaceutical ingredient plants, September 2016