Defining Safety Precautions for Category 4,5 Molecules

Categorization of molecules is depending on OEL values 'occupational exposure levels'
OEL = [(NOEL) x (human body weight)]/[(safety factor)n x (human breathing
* NOEL is typically in units of milligram of chemical administered/kilogram of animal body weight/day;
* Human body weight typically is assumed to be 70 kiligrams for an adult male;
* Safety factors for accomodating limitations in the data, as described above; and
* Breathing rate in workers typically is assumed to be 10 m 3/8-hour workday.
{ Occupational health categorization and compound handling practice systems— roots, application and future

Occupational Exposure Bands (OEBs)


controls are proportionate to the oels (obviously increasing towards category 1--> 5)

my question is...
can we additionally factor the activity-exposure risks/levels to calibrate the controls.
viz., a powder handling having maximum controls (viz., dedicated-controlled environments), and
once solubilized, once it enters the liquid state, reducing the levels of controlled environments!

can this approach of activity-exposure-levels/risks to harmones' 'cytotoxic products' etc
The approach of 'proportionate controls' with respective risk-exposure levels is appropriate.

final criteria would be 'compliance to legal/regulations' from respective geography. it is noted that agencies are usually open to engage a debate on the 'risk / rationale of stated approach'; and other may not be so.

hence, it all depends on the authority on other side of desk, to accept/allow the proposed approach!!! (that is a huge uncertainity and risk!)


Captain Nice
Staff member
Sorry no one answered your question.

Thanks for stopping back and updating this thread with what you found. We all appreciate it!

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