Recently one of our members contacted NSF to inquire about the requirement for alarms on canopies attached to recirculating Biosafety Cabinets. We wanted to post this so members are aware of this coming requirement and can inform your administration, certifiers and other relevant personnel, in preparation for compliance with this requirement.

Here is a snippet of the email sent to NSF:

It is our understanding that NSF certifications applying the version of Standard 49 that was in place at the time equipment was manufactured is acceptable. Therefore, for BSCs w/ canopy manufactured before 2010, the installation of an alarm, although recommended, is not a  requirement.

We have recently learned, however, that this will become a requirement for all BSCs regardless of their year of manufacture. Is that correct?

Here is the response from NSF:


Your understanding of the Standard 49 requirements related to canopy connections is correct at this point in time.  I.e. the memorandum currently posted on NSF’s website at is still in effect.

NSF hopes that biosafety officers and field certifiers responsible for a given facility will work together to determine whether to retrofit canopy-connected type A cabinets manufactured prior to 2012 with alarms.  This decision should be based on the intended and potential procedures to take place inside the bioasfety cabinet (for example, if the exhaust system fails, the biosafety cabinet is designed to still function properly with respect to biologicals, but what if a certain procedure being performed in the work space generates odors, etc. that cannot be HEPA filtered?).

The Steering Committee for NSF’s Biosafety Cabinet Field Certifier Accreditation Program voted unanimously in April 2013 to request that NSF reconsider the wording of the memo referenced above and establish a date (suggested at early 2014) by which all type A cabinets with canopies must have alarms.  However, because NSF’s standards and policies development processes are not developed by NSF employees, but are developed with input from a number of stakeholder groups such as the Standard 49 Joint Committee and NSF’s Certification Council, this request cannot be processed unilaterally without input from the other groups.  Once they are available, I will forward a copy of the Steering Committee meeting minutes to NSF’s Standards Department so that they can present the Steering Committee’s request to the other two committees described above.  However, it is unlikely that the Steering Committee’s request will be considered immediately, as the biosafety expert in the Standards Department recently left the company (and in fact, half of the Standards Department is being replaced at the moment).


Kind regards,

Maren Roush


Senior Project Manager, Biosafety and DWTU Programs

NSF International

Phone: (734) 827-6821

Fax: (734) 827-7147