Frequently Asked Questions
Biological Safety Topics

How long does diluted bleach last?

For the answer to this question, see the clorox@casupport.com email to the Director of WCMC EHS dated February 6, 2003:

Thank you for asking about the shelf life of Ultra regular CLOROX liquid bleach.

When bleach and water are mixed together to create a cleaning or disinfecting solution, the solution is only good for 24 hours. The temperature of the water does not affect the cleaning or disinfecting abilities of the solution. After the 24 hours, the solution begins to lose needed disinfecting properties. Therefore, it is recommended that for disinfecting purposes, the solution is made fresh daily.

Our bottles do not have an expiration date, however, they do have a production date. Once you understand how to read the production date, you can decipher the shelf life of the bottle. Please look below for a chart explaining our production codes.

CODE	PLANT	YEAR	DATE
MD21002	MD2	1= 2001	002nd day of year
A90288	A9	0= 2000	288th day of year

We recommend storing our bleach at room temperatures. It can be stored for about 6 months at temperatures between 50 and 70 degrees Fahrenheit. After this time, bleach will be begin to degrade at a rate of 20% each year until totally degraded to salt and water. Storing at temperatures much higher than 70 degrees Fahrenheit could cause the bleach to lose its effectiveness and degrade more rapidly. However, if you require 6% sodium hypochlorite, you should change your supply every 3 months.

I hope this information is helpful. Again, thank you for giving me this opportunity to discuss our product.

Sincerely,
Mary Brylinski Product Specialist

MEB/cl
3463673A

How often does a biological safety cabinet have to be certified?

Generally, biological safety cabinets (BSC) must be certified on an annual basis. Some special operations may require certification every six months. Relocating a BSC requires re-certification and may require decontamination. Contact the Biological Safety Officer at EHS when a cabinet is to be relocated.

According to the College's "Waste Disposal Procedures" a sharp is any glass, metal, plastic instrument or item that can cut or has the potential to cut, puncture, scratch or abrade skin, whether it is contaminated or not. Using this definition a pipette tip is considered a sharp and must be placed in a sharps container. If you have any doubt, use a sharps container for disposal.

When does work with recombinant DNA or other biological materials require approval?

All research involving recombinant DNA (including transgenic animals and gene transfer) must be reviewed by the Institutional Biosafety Committee (IBC) prior to its initiation. Forms to be filed for reporting such research to the Committee can be obtained from the Grants & Contracts Division of Research and Sponsored Programs. In addition, certain specific categories of research, designated by the National Institutes of Health (NIH), Office of Biotechnology Activities (OBA), require prior notification and/or prior approval by the NIH before initiation. Reporting such research to other Federal agencies (e.g., FDA, CDC) may be required in special circumstances. Faculty initiating research involving development of transgenic animals or gene transfer should consult with the Biological Safety Officer (BSO), who can be reached through Environmental Health and Safety, for advice on reporting/approval requirements in specific cases.

Which Clorox products are EPA-registered disinfectants?

For the answer to this question, see the clorox@casupport.com email to the Director of WCMC EHS dated March 28, 2003:

Thank you for your recent email. We appreciate your interest in our products.

The following products are EPA registered disinfectants:

• Ultra regular CLOROX liquid bleach
• Ultra CLOROX Germicidal Bleach
• Ultra Institutional CLOROX bleach

I hope this information is helpful.

Again, thank you for contacting us.

Sincerely,

Jyll E. Bowman Product Specialist

JEB/cl

3536264B

Can I use a bunsen burner inside a biological safety cabinet?

Most biological safety cabinets at the College recirculate air within the cabinet allowing flammable gases to concentrate. Therefore, Bunsen burners which use natural gas and other flammable gases should not be used within a biological safety cabinet. See the EHS Update "Flammable Gases in Biological Safety Cabinets" for further information.

Are human cell lines applicable to OSHA's Bloodborne Pathogen Standard?

Yes, the Occupational Safety and Health Administration considers human cell lines applicable to the bloodborne pathogen standard. Human cell lines at the College are treated at least at Biological Safety Level 2 (BSL2). The following Frequently Asked Question regarding human cell line biosafety from ATCC provides additional insight.

 

I don't want to change my bleach squirt bottle daily. Are there any other options?

Yes, there are products that leave bleach and other disinfectants in their concentrated form until they are used. An example is the "Fresh-mix Bleach Sprayer" from MarketLab. Other products are available. If you have a products you have found useful, please let us know.

 

Can I use paraformaldehyde to decontaminate my contaminated equipment?

No, the paraformaldehyde decontamination procedure can be very dangerous if not performed correctly. This procedure may only be performed by trained professionals with appropriate equipment. Contact EHS or an approved certifier for more information.

I work with mice. Do I need to attend the Bloodborne Pathogen training?

If you are injecting mice with any bloodborne pathogens like human cell lines, HIV, Hepatitis B virus, Hepatitis C virus, you fall into the OSHA Bloodborne Pathogen requirements and must attend the WMC Bloodborne Pathogens training.