3 years ago
Changes Coming to NFPA Standards on Hazmat Clothing
The NFPA Technical Committee on Emergency Response Protective Clothing and Equipment is responsible for NFPA Standards 1991, 1992 and 1994.
The NFPA Technical Committee on Emergency Response Protective Clothing and Equipment is responsible for NFPA Standards 1991, 1992 and 1994. This committee has been very busy over the last couple of years processing revisions to these documents. The actual revision process itself is very structured by the NFPA and takes at least two years to complete. The committee meets about twice a year and also conducts numerous conference calls. The committee is made up of a mixture of fire service and military users, testing laboratories, manufacturers and independent experts.
The NFPA 1991 – 2005, Standard on VaporProtective Ensembles for Hazardous Materials Emergencies, has been in effect for much longer than normal, which is typically five years, because of issues that could not be resolved in the standards revision process. An attempt was made to publish the standard with a 2012 edition, but the NFPA Standards Council would not approve it and sent it back to the technical committee for further work. The primary issue of debate related to how chemical barrier permeation testing would be conducted by the laboratories.
The method used by the chemical protective clothing industry for the last twenty years was to be replaced by the method used by the US Military for the last sixty years.
The industry method, ASTM F 739, used the concept of measuring initial detection but evaluating the barrier performance by reporting breakthrough times at a certain level of chemical exposure. The military method, which followed generally MIL-STD-282, evaluates barrier by measuring the total quantity of chemical that permeates in a given period of time. This method is referred to as “cumulative permeation”. The military used this approach because they had measured the quantity of chemical warfare agent that would harm the skin or cause injury based on skin exposure. This was based on such chemical warfare agents as mustard (HD) and sarin (GB). This approach will now be applied to the industrial chemicals that are specified in ASTM F1001, Standard Chemical Battery. This biggest problem with new approach is that it took us twenty years to train users on the method that utilized breakthrough times. Another major change to NFPA 1991 involves the whole garment vapor inward leakage resistance. The method that was in the standard for the last twenty years was only specified in the NFPA standard itself. It had not been through proper interlaboratory evaluations that would be required of an ASTM or ISO standard for example.
The method was a challenge to conduct by the laboratories and also required cutting holes in the garment itself to install sampling lines used during testing. During early stages of NFPA standards development for chemical protective clothing many tests were specified that were not approved methods by ASTM or ISO.
The new method has been used in NFPA 1994 for several years and has also been published as an ASTM standard ASTM F2588 – 2012, Standard Test Method for Man-In-Simulant Test (MIST) for Protective Ensembles. This method was also originally developed by the US Military and has been in use for many years as well. This method involves the use of absorptive detector pads that are placed on the subject before donning the protective garment. The subject enters a chamber that contains methyl salicylate, more commonly known as oil of wintergreen. After the wear evaluation, the pads are removed from the subject and placed in a device to detect any absorption of the methyl salicylate. Based on the absorption detected, a physiological protective dosage factor (PPDF) is calculated. Other less significant changes have been made, including changes to the flame resistance testing for materials certified to the Base requirements of the standard, new visor impact and cold temperature testing, and new field of vision testing.
The changes to the NFPA 1992 and 1994 standards are still in process, but many changes have already been made to these, particularly 1994. These standards are scheduled to publish effective May 2017 and will meet the five year requirements for revision. NFPA 1992-2017, Standard on Liquid Splash-Protective Ensembles and Clothing for Hazardous Materials Emergencies, does not contain the significant changes that are occurring in 1991 or 1994. The chemical battery has been revised and expanded to ten chemicals. Visor impact and cold temperature testing has been revised to be consistent with the changes in NFPA 1991.
NFPA 1994-2017, Standard on Protective Ensembles for First Responders to CBRN Terrorism Events, has several significant changes, but most importantly the scope of the standard. The scope previously was limited to emergency responses to CBRN Terrorism events and not hazardous materials emergencies. The new scope as currently written is: This standard shall establish the minimum requirements for design, performance, testing and documentation and certification of protective ensembles and ensemble elements used during hazardous materials and chemical, biological or radiological terrorism incidents. The change to include hazardous materials is a major change to this standard. This change, coupled with the change to include again a Class 1 ensemble in the standard, creates concern for some committee members.
The greatest concern expressed by some committee members was the challenge that will now be placed on the user community to determine when a 1991 ensemble is appropriate and when a 1994 Class 1 ensemble is appropriate.
The 1994 Class 1 ensemble requirements are similar to those for NFPA 1991 base requirements with the primary difference being a modification to the chemical challenge. The challenge level for NFPA 1991 is 100% liquid or vapor challenge. The challenge level for 1994 Class 1will be 10,000 ppm liquid or vapor challenge. The chemical list for Class 1 will be slightly different than 1991 as well.
Another change will allow the use of non-encapsulating ensembles, which has never been allowed in 1991. This change is significant because the SCBA will now be worn on the outside of the ensemble barrier. This creates concerns that the SCBA has not been tested for chemical resistance consistent with the ensemble itself. It also presents an issue that the SCBA could be contaminated during use and would require additional decontamination and inspection for reuse, or the monetary issue of the replacement of the breathing equipment.