DCHAS-L Archives ยท Post dated August 13, 2009
From: Harry J. Elston <helston**At_Symbol_Here**FGI.NET>
Subject: Re: Extinguishers and gloves
Date: Aug 13, 2009 16:37 UTC
Reply-To: "Harry J. Elston" <helston**At_Symbol_Here**FGI.NET>
In-Reply-To:
Two notable exceptions to Jay's wisdom: 1. There may be regulations regarding prepared standards in certified laboratories, such as ones that perform organic or inorganic analysis for drinking water. I would first go to the EPA Laboratory Certification Manual (now in it's 5th edition) for guidance there. I believe it's 6 mo or a 1 year, but don't quote me on that. I do know that auditors will give you the fish-eye for having calibration standards older than 6 months for organics standards and 1 year for inorganic standards, and may even make these a "finding" on an audit. 2. Prepared radiological standards are usually kept until they are no longer useful because of decay problems. Depending on original source strength, isotopic half-life and counting instrumentation, that could mean days, years or decades. Other concerns that you need to be aware of are cross-contamination problems (i.e. sticking a pipette contaminated with another standard into the bottle) and concentration issues (i.e. leaving the cap loose). Both of these are training issues. -----Original Message----- >From: "Dr. Jay A. Young">Sent: Aug 13, 2009 10:04 AM >To: DCHAS-L**At_Symbol_Here**LIST.UVM.EDU >Subject: Re: [DCHAS-L] Assigning expiration dates > >Roger, > >To establish an expiration date for any locally prepared reagent or reagent >mixture requires a reasonably thorough knowledge of the properties of each >of the components that are involved--all of which would of course include >the supplier's recommended expiration date for one or more of the >components--but that information would NOT be the sole factor. > >In practice, the above required information often is not always available. >In such cases, one simply has to fly by one's pants (so to speak). I >recommend setting a brief arbitrary period of utility, say 3 (or perhaps 6) >months from the date of preparation but in no case greater than 6 months. > >Then, if the date selection is, say, 5 months, test the stuff at the end of >4 or 4.5 months and if it is still OK, then, arbitrarily extend the >expiration date to, say 7 months and so on. > >Thus, test it again at 6.5 months and if OK extend to 8 months. Etc. > >But in no case for a standard would I use it as a standard after one year. >And of course, in some instances, it would be necessary to store a standard >under controlled conditions for the entire period of its valid use. > >Jay Young >************************* >----- Original Message ----- >From: "Roger Brauninger" >To: >Sent: Wednesday, August 12, 2009 3:58 PM >Subject: [DCHAS-L] Assigning expiration dates > > >>I was wondering if there is a rule of thumb for assigning expiration dates >> of working stocks, etc. For example: An analytic method specifies that a >> given standards solution (A) is good for one year (expires a one year >> after >> preparation). "A" is made from a commercially prepared standard, which >> has >> its own expiration date. In the situation where the expiration date on >> the >> commercial material is one month after the current date and a solution of >> "A" is made up from it, is the expiration date still one year after the >> date >> of "A's'" preparation or much it be restricted to the expiration date of >> the >> commercial standard. In this case one month. >> >> To add to the discussion the Code of Federal Regulations, 40CFR, Section >> 58.113, (c ) states, "Where any of the components of the test or control >> article carrier mixture has an expiration date, that date shall be clearly >> shown on the container. If more than one component has an expiration >> date, >> the earliest date shall be shown." >> >> This is a difficult issue to come up with a unilateral approach because we >> have seen instances where the exact same neat materials (Reference >> Materials >> for example but it could be any chemical for that matter) which are sold >> by >> different manufacturers have had different expiration dates assigned to >> them. So there is variability even with the neats. The GLP approach is >> certainly valid for a number of materials however, for example >> radioisotopes >> but assigning an expiration date also depends on other properties of the >> materials, for example whether they react or degrade (organics for >> example), >> or do not (most metals). Most producers say that it is appropriate to >> re-qualify a material. However it all boils down to having knowledge of >> the materials at hand and the purpose for which they are used. >> >> Thoughts? >> >> Roger M. Brauninger >> BioSafety Program Manager >> >> 5301 Buckeystown Pike >> Frederick, Maryland 20895 >> Direct line: (301) 644-3233 Fax: (301) 662-2974 >> Email: Rbrauninger**At_Symbol_Here**a2la.org >> >> www.a2la.org <http://www.a2la.org/> >> >> The information contained in this transmission may be confidential >> information intended only for the use of the individual or entity named >> above. If the reader of this message is not the intended recipient, you >> are >> hereby notified that any dissemination, distribution or copying of this >> communication is strictly prohibited. If you have received this >> communication in error, please notify us immediately by telephone and >> delete >> the original message. Thank you. >> >> Harry J. Elston, Ph.D., CIH Principal Midwest Chemical Safety, LLC www.midwestchemsafety.com Editor, Journal of Chemical Health & Safety http://membership.acs.org/c/chas/ Nationalized health care: All the efficiency of FEMA with all the compassion of the IRS