[Histonet] discarding old dry chemicals with no expiration date

Owen, Michael P Michael.Owen <@t> fda.hhs.gov
Wed Sep 30 12:40:56 CDT 2009

My laboratory had many chemicals that were over 10 years old when the
facility started to prepare for ISO 17025 accreditation status four
years ago.

The facility's current policy for stock chemicals without expiration
dates is to set a 5-year expiration period from the date the substance
is received by the laboratory.

Prepared reagents and working solutions have one-year expiration periods
from the dates they are made.

Histochemical dyes have been shown worldwide to last for decades in
their dried forms. In an emergency, dyes older than five years would
probably be acceptable. 

If a dye can no longer be obtained, the main reason an expired dye is
being kept, the method using the dye needs to be updated to use dyes
that are currently being manufactured. A good method is one that can
reproduced reliably based on readily-available reagents. :o)

Michael P. Owen, Regulatory Microbiologist
U.S. FDA Pacific Regional Lab Northwest
22201 23rd Drive SE  Bothell, WA 98021-4421
Phone: 425-483-4865     E-Mail: michael.owen <@t> fda.hhs.gov

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