References

What is AFNOR NFX 15-211?
This standard was published in France in September of 1996. It was written by the UNM61 Committee that was chaired by ERLAB DFS SA which is also the French manufacturer of the Captair ductless fume hoods –(ETRAF).

Simply stated, the AFNOR standard requires that the manufacturer stipulate the retention capacity of its activated carbon filter for each of three chemicals and that it tests the filter in four phases to determine if it can retain that stated quantity while releasing less than TLV quantities of that chemical during each phase. The allowable amount varies with the least amount of desorption allowed in Phase One and the most allowed in Phase Four.

Under this protocol manufacturer A might, for example, claim a retention capacity of 1000 evaporated grams for chemical one while manufacturer B might claim a retention capacity of 50 evaporated grams for that same chemical. Conceivably both manufacturers could pass the test requirements based on their stated filter retention capacities and be considered to be equally in compliance with the AFNOR NFX 15-211 standard.

The theory is that the user will go beyond just finding out that both manufacturers are in compliance and will evaluate and compare the actual filter retention capacities at which each passed the test. In fact, however, we shall see later on that based on past history these tests are not well understood and this does not happen in actual practice.

Are all chemicals authorized to be used by the Manufacturer required to be tested to maintain compliance with the AFNOR standard?
Most manufacturers of ductless fume hoods claim that their equipment can be used with 600 to 800 commonly found chemicals in typical lab applications. AFNOR NFX 15-211, however, does not require that these all be tested to the standard and assumes that if the three test chemicals pass then all the others will pass as well.

A further complication not addressed by the AFNOR standard is that frequently chemicals in a lab are used in varying combinations within the same enclosure and filter. In these situations the filter retention capacity is not additive for the combined chemicals. Rather the interactions complicate the predictability of filter retention. This subject is totally overlooked by AFNOR even though in actual practice this type of usage is more the rule than the exception.

Does AFNOR require test updates when the TLV of the tested chemicals change?
Historically the more we have learned about chemicals the more we realize the dangers they pose. Over time the pattern has been to reduce the TLV limits to reflect this increased concern as to the effects that chemicals have on our health. There was a time, for example, when benzene was commonly used on our open work benches for the cleaning of parts. Now we know better and the TLV on that chemical was reduced in the mid 1990’s from 10 ppm to just 0.1 ppm. That is just one example of many such reductions that have occurred. Yet AFNOR ignores the question of re-testing when new and tighter TLV limits are established.

How effective has the AFNOR NFX 15-211 Standard been in terms of achieving acceptance and promoting operator safety?

Not surprisingly because of its role in writing the standard , Erlab is the chief proponent of this standard – calling it “the most demanding standard concerning filtration efficiency and the protection of the user”. Yet we know that it has not received international acceptance or promoted a spirit of cooperation among the manufacturers of ductless fume hoods.

It may be helpful to study the ERLAB experience and take a closer look at the claims it makes relative to the AFNOR standard to better understand why the standard is controversial and why no U.S. company has as yet seen fit to test its ductless fume hoods to this standard.

The claims listed below concerning the AFNOR standard can be found at the Erlab web site www.Captair.com.

CLAIM: “The Captair ductless fume enclosures are presently the only ones to comply with the most demanding standard worldwide with regards to ductless filtration and user protection: the AFNOR NF X 15-211….”

A number of well respected overseas manufacturers of ductless fume hoods have claimed to be in compliance with AFNOR NF X 15-211 and show evidence of having test reports. These include: Bigneat LTD, Crumair and ESCO. The Erlab claim of exclusivity appears disrespectful to these other competitors and a sure way of promoting disharmony rather than cooperation.

CLAIM: “ It is not enough to claim to comply with the most demanding standard worldwide concerning the protection of the user, the AFNOR NFX 15-211 Standard, it is necessary to prove it. ASK US FOR OUR TEST REPORTS.” The test report provided by Erlab as proof of its compliance with AFNOR is one that was done in 1992 ( some 14 years ago) and well before the AFNOR test protocol had been written and approved. In that 1992 test the TLV used to test Benzene was 10 ppm whereas the AFNOR protocol as written in 1996 would have required that Benzene be tested at 0.1 ppm . On that basis alone, the results of that 1992 test could be seen as meaningless in terms of showing compliance with the AFNOR standard.

Interestingly enough that discrepancy has larger been ignored by users and competitors alike. This supports our contention made previously that manufacturers that pass the AFNOR test but at different retention levels would not be subject to comparisons and all would be seen to be in equal compliance regardless of how effective the filters were in actuality.

CLAIM: “The Enclosures for Toxics using Recirculating Air Filtration (ETRAFs) manufactured by Erlab® are the only ductless fume hoods worldwide to comply with the most demanding standard concerning filtration efficiency and the protection of the user : the AFNOR NF X 15-211 standard (standard certification performed by the LNE : National Testing Laboratory).”
Standard certification performed by the LNE would imply that the product was tested to AFNOR NFX 15-211 by the LNE and found to be in compliance. In point of fact we have been told by the LNE both verbally and in writing that they have not tested any ductless fume hoods (ETRAFs) to AFNOR NFX 15-211.

Over the last six months we have asked that Erlab either modify the claims on their website or provide credible proof of an actual AFNOR NFX 15-211 test to support those claims. To date that website has not been modified nor have we seen an actual test done subsequent to the establishment of AFNOR NFX 15-211 in 1996.