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    More than 3,000,000 American laborers are required to fit test equipment and to wear respirators to shield themselves from risks in their working environment and occupational hazards. Since the position of the respirator to the user’s face affects the assurance gave by the respirator, occupational security and wellbeing experts prescribe fit appraisal during the underlying choice of a respirator model and at some periodicity as a major aspect of a respiratory protection program. In 1998, the Occupational Safety and Health Administration (OSHA) adopted new guidelines for occupational respiratory safety systems allowing respiratory patients to receive training and clear a fit test before using a respirator, and every year from there on (29 Code of Federal Regulations Section 1910.134), in view of current ANSI benchmarks and open remarks referring to working environment experience.


    Fit testing is the only accepted approach to decide whether the respirator fits appropriately. Periodic monitoring is necessary to ensure the match remains acceptable. One position is that yearly retesting of respirator fit is expected to recognize, at a beginning period, the percentage of respirator users whose respirators never again fit them appropriately. Another viewpoint contends that fit testing ought to be required just when a worker changes to an alternate respirator or when a noteworthy change happens in a person’s physical condition which may meddle with acquiring a satisfactory face seal.


    The current fit test necessities and the justification were addressed at the 2004 Centers for Disease Control and Prevention Workshop on Respiratory Protection for Airborne Infectious Agents in Atlanta, Georgia where members required the measurement of the advantage and the logical legitimacy of yearly fit testing. Members addressed whether yearly fit testing must be acted in a similar whole and way as beginning fit testing and inquired as to whether yearly fit testing could be overhauled to just confirm appropriate wearing of the respirator and acceptability of fit. The workshop additionally featured the need to measure the job of weight reduction or increase in fit testing.

    In order to address many of the questions surrounding the periodicity of respirator fit research, NIOSH recommends a first-of-its-kind analysis to determine improvements to respiratory performance and facial measurements as a function of time for a representative sample of people wearing respirators. NIOSH will employ 220 study participants (subjects) from the U.S. population and will be spread across the 10 facial size and face length ranges. NIOSH must gather a series of 13 conventional face dimensions, height, weight, and a scanned image for each person, using a Cyberware Model 3030 head scanner at the beginning of the study and for three years every six months thereafter. For participation in the sample, participants will be required to pass a respirator fit test. In the study, all members will be maintained regardless of future suit adjustments. The rate at which the respirator works varies will be calculated as a function of the time.

    It will also investigate possible associations between physical changes and improvements in respirator performance. Knowledge obtained from this work will be used to formulate hypotheses for further experiments and address more questions surrounding the periodicity of respirator match tests.