arpadveress 
Grades of release (or types of source)
Three grades of release 3 are defined in terms of their likely frequency and duration.
Continuous grade release
A release which is continuous or expected to occur for long periods: the cumulative duration of release exceeds 1000 hours per year.
Example: Gaseous atmosphere in a hydrocarbon storage tank.
Primary grade release
A release which can be expected to occur periodically or occasionally during normal operation:
the cumulative duration of release is in the range of 10 to 1000 hours per year.
Examples: Sampling connection (for regular, open to atmosphere sampling), operating purge, drain.
Secondary grade release
A release which is not expected to occur in normal operation and, if it does, is likely to do so only infrequently and for short periods: the cumulative duration of release is less than 10 hours per year 4.
Examples: Flanges, pump seals.
All need to be identified and tracked if not room based you proceed. You shall always choose but then follow your methodology. Mixing possible, but not recommended.
Keep up good work
Arpad
