[Histonet] handling blocks (Muhammad's inquiry)

Cheryl tkngflght <@t> yahoo.com
Sat Oct 23 18:33:36 CDT 2010

in consideration of the status of paraffin blocks...
Assuming you've done a good job in fixing prior to and during processing and you don't encounter prion diseases, processed/blocked tissues are inert.  Theoretically, you could eat them with no adverse issues other than paraffin sticking to your teeth.  We've all heard the story of a safety officer trying to convince a histology manager that blocks were biohazardous.  The safety officer was certain gloves were needed and wasn't allowing any discussion until the manager picked up a block,  looked the S.O. in the eye and licked the cut surface of the block.  End of discussion.  
Have you considered if you declare these blocks contaminated, the impact for discarding them over time?  Cutting would then be a situation creating aerosols so you'd need masks and negative pressure on the cutting room. If you call them biohazardous, then you also have to discard them as biohazard waste, as well as all the fluids and paraffins and extraneous waste involved in processing and cutting them.  Storage and transport of blocks, such as to a reference lab, would require biohazard tracking....etc.  Do you really want to impact your lab this significantly for something that has no documented history of biohazard? (Unless you work with prion disease!!) 
Any verified cases of infection or problems out there?  
We do know many people who cut and embed with gloves by choice, not as a requirement.  Most of us have decades of experience cutting and handling blocks barehanded...why create more work & expense for no documented, proven reason?
Cheryl Kerry, HT(ASCP)
Houston, TX


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