10 months ago
Recent Changes to NFPA 1991
The new edition of NFPA 1991, Standard on Vapor-Protective Ensembles for Hazardous Materials Emergencies, became effective in December of 2016.
Several significant changes were made to the standard during this revision.
The first change involved the way in which permeation testing was conducted on fabric, seams and components. All previous editions of NFPA 1991 reported chemical breakthrough based on the permeation rate exceeding a minimum allowable value. This method was described as normalized breakthrough. The new edition uses an analytical approach called cumulative permeation. This approach has been used for years by the US Military. It measures the total quantity of chemical that permeates in a given time period. If the quantity exceeds the minimum allowable amount, the test is considered a failure.
Other changes involve physical test methods on footwear, gloves and visors.
The other significant change involves the whole garment or system test. In the previous edition, the whole garment test was using sulfur hexafluoride as the test agent. The problem with this test is that you had to poke holes in the garment to place sampling lines into the garment. The new test uses a whole different approach that has previously been used in NFPA 1994. The Man in Simulant Test (MIST) has been used by the military for years. It does not involve the use of sampling lines. In this test a series of absorptive pads are placed on a live subject and they then donn the garment. The subject enters a chamber that is filled with an agent called methyl salicylate. The concentration of the agent is measured inside the room and then measured from the collective pads inside the garment. A protection factor is then calculated.
So again we have eliminated the sulfur hexafluoride and incorporated the MIST test.
The chemical test battery has also changed slightly. The test battery has historically included the ASTM F 1001 test battery of fifteen liquids and six gases, with the addition of four additional toxic industrial chemicals and two warfare agents. The list of the four toxic industrial chemicals (TIC’s) has been changed to be consistent with the TIC’s specified in NFPA 1994.
So these are the most significant changes to NFPA 1991. Kappler has certified their Frontline 500 garment to the new edition and it is available for purchase today.