required to be repeated every six months for jobs with exposures over the action level, and quarterly for jobs with exposures over the PEL. OSHA does not require that every employee be sampled but sampling must be representative of all of the employee’s potentially exposed above the action level. Any employee who’s affected must be notified within 15 working days of the results and this applies to any exposure assessments and is required whether or not the action level or PEL has been exceeded. If the PEL is exceeded, a description of corrective actions to be taken by the employer is required with the notification.
Compliance Methods OSHA stresses its position on
the hierarchy of controls. Te order of preferred controls is elimination, substitution, engineering controls, administrative controls and per- sonal protection equipment. When planning to comply with the new standard, it’s important to note res- pirators are not considered controls. When employees are working in jobs that exceed the PEL, employers must provide respiratory protection until exposures are reduced below the PEL and pursue feasible controls. Te burden to show that a control
isn’t feasible is on the employer. In OSHA’s view, engineering
controls are reliable, predictable and provide consistent protection, can be monitored constantly and easily and aren’t susceptible to human error. Exposure reduction can be achieved via substitution, ventilation, isola- tion, dust suppression or process changes. Te way employees perform tasks can be modified, though that requires training to know how prac- tices create exposure. If silica containing abrasives are
used, the hierarchy of controls also needs to be followed. Non-silica containing abrasives should be considered, but even when used, respirable crystalline silica exposures can still occur when sand is removed from castings. As for simply rotating employ- ees out of areas where there is silica
Engineering controls, more than respirators as shown here, are seen by OSHA as reliable and dependable methods of keeping workers safe.
exposure, OSHA didn’t prohibit the practice but doesn’t consider that to be an acceptable alternative to avoid costs. It also doesn’t think pervasive exposures to respirable crystalline silica justify allowing rotation. Respirators are required and
must be used properly when the PEL is exceeded. Tey are allowed to be used in four circumstances: until controls are installed and implemented and successfully reduce exposures below the PEL, when controls are not feasible, when controls cannot sufficiently reduce exposures below the PEL and when employees enter regulated areas. OSHA thinks respirators are less reliable than engineering and work- practice controls and do not provide a level of protection the equivalent of engineering controls.
Regulated Areas A regulated area is an area where
an employee’s exposure to airborne
respirable crystalline silica exceeds, or can reasonably be expected to exceed, the PEL. Designating these areas helps raise awareness and reduce the number of employees exposed over the PEL. Just because a particular employee’s exposure assessment results indicate the employee’s exposure is above the PEL, does not mean every area the employee visited on the day he or she was sampled exceeds, or can reasonably be expected to exceed, the PEL. Establishing the boundaries of the Regulated Area will be challeng- ing when employees move around. Companies are required to
demarcate the area, post a sign with specific wording at entrances to the area, and limit access to these areas. Everyone entering the regulated area must wear a respirator.
Housekeeping
OSHA concluded wet meth- ods and HEPA-filtered vacuums are highly effective. It also believes compressed air, dry sweeping and dry brushing contribute to employee exposures, and there’s evidence wet method and HEPA vacuuming might not work in all situations. Te stan- dard allows dry sweeping and brush- ing in limited circumstances where wet methods and the use of HEPA vacuums are not feasible. Compressed air can be used for cleaning where it is used in conjunction with ventila- tion to collect the dust. It is important to note the
Scheduled monitoring entails initial testing that reflects a
worker’s personal breathing zone time weighted averages exposures for each shift and for each job
classification in each area. December 2016 MODERN CASTING | 33
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