Dirty Equipment Hold Time (DEHT)

Duration before cleaning

Abbreviated as "DEHT" or "DHT" and commonly reffered to as "soiled hold time" or "dirty hold time". Dirty equipment hold time is defined in PDA Technical Report 29, Points to Consider for Cleaning Validation as "The time from the end of product manufacturing until the beginning of the cleaning process". Validating the dirty equipment hold time allows for equipment to be held in a soiled state for a peroid of time prior to initiaiting cleaning activities. This allows the production schedule to continue more easily without the need to immediately clean equipment and attend to other processess in addition. The DHT is validated across three consecutive major cleaning process for a single product.