[Histonet] Bleaching in the histo lab

WILLIAM DESALVO wdesalvo.cac <@t> hotmail.com
Wed Feb 1 09:08:07 CST 2012

The short answer is that you need a detailed procedure for all immediate and regular cleaning of infectious materials and hazardous chemicals used in your lab.
I believe the standard practice your safety officer is referring used in the clinical lab is a practice to clean all surfaces after each shift to remove/decontaminate all contaminated or potentially contaminated from the work surfaces of blood or other infectious material w/ 10% bleach solution (1:10 dilution of 5.25% solution of sodium hypochlorite) or other lab cleaners approved for biohazard approved contamination. The waste generated by this process should be disposed of in the non-regulated medical waste. Typically in the Histology room there should not be blood or other infectious materials (you are working w/ fixed and processed tissue samples), unless you have your frozen section and/or gross dissection processes connected to and part of the main Histology room. I suggest you use the bleach solution whenever there is known or suspicion of contamination of a potentially infectious material.
For areas/surfaces and equipment where lab chemicals are used, always remove the spilled chemical according to MSDS recommendations and then clean the area w/ a damp cloth with water and a detergent and them wipe clean and dry. If or when a hazardous chemical is spilled (i.e. Xylene, Formalin or chemicals associated w/ IHC or Special staining), it should be treated as a hazardous chemical spill and there area should be cleaned according to your hazardous chemical spill protocol. Small spills (up to 300 cc) - neutralize and/or adsorption; medium spill (300 cc to 5 liters) - adsorption spill kit; Large spill (>5 liters) - outside help. disposal will be in regulated hazardous waste.
The main point here, instances of contamination of infectious materials or any size spill of hazardous chemicals should be treated seriously and properly. Your cleaning and disposal procedure must be very detailed to protect the employees and meet lab, municipality, state and regulatory requirements. I am very passionate about properly handling chemicals and protecting everyone that must have contact w/ these necessary solutions/products. I suggest you and your safety officer have a sit down and discuss how to document and address these issues, a drive-by by a safety officer is really not adequate.
William DeSalvo, B.S., HTL(ASCP)


> Date: Wed, 1 Feb 2012 05:57:27 -0800
> From: we3smitty <@t> yahoo.com
> To: histonet <@t> lists.utsouthwestern.edu
> Subject: [Histonet] Bleaching in the histo lab
> I have been told by our safety officer that it is standard practice too clean the lab at the end of the day with diluted bleach. I have noticed a chemical reaction (smell) when cleaning the main area of the lab. I have concerns that this is not a good practice due to chemical reactions as we use so many chemicals in histology. What do other people do?  Also I believe it is unsafe to use bleach with anything formalin related. 
> Please let me know if you have a "standard" practice or mandated cleaning from your facility.
> Angela 
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