DEP advisory to residents regarding WTC dust, Oct 2001

NYC 9/11 Public Portal Document

f Fax:-^ Aug 2 2000 00:34 P.04 ^28-2001 FRI 10:24 A« HIOSH/R-II FAX NO. 5134587147 P. 02

NIOSH GUIDANCE ONRESPIRATORY PROTECTION FOR WTC WORKERS

Thii is a r'jir.mary of the respiratory' protection recommended for workers on, above, or near the WTC rubble pile. It includes guidance expanding the types of facepieces and particulate filters that should be used. Be aware that ongoing worker exposuru assessments may result in further or more stringent respiratory protection recommendations for ’WTC -workers.

Elastomeric, air-purifyinx? half-facepieces

Factors considered when selecting respiratory protection include documented and potential airborne hazards, the physical characteristics of a work area, the physical demands on workers, and the advantages, disadvantages, and protective capabilities of respirator;- Non-powcred, fiir-punfymg respirators arc light-weight and give workers mobility. Both are key f’ctcr; for WTC workers. A half-^ceplece respirator that is properly used and fit tested will reduce worker exposures to s.bout 10% of what it would be without the respirator.

Because eye protection is also important for WTC workers, goggles should be worn ’with half-facepiece respirators Full-facepiece, flir-purif^ina respirators could be an alternative to provide needed eye protection; howcvc^they may interfere with field of vision. A fu’l- fac&picoc respirator that is properly used and fit tested will reduce worker exposures to about 2'/:. of what it would be without a respirator

P-U)0 particulate filters

Because of potential worker exposures to airborne asbestos, using high-efficiency filters recommended (reference: OSHA 1910.1001) The P-category of resistance to filter- efficiency degradtiiion (oil-Proof) was recommended because the presence of oil acrosok- among the contaminams was v.ncort-ain, and unlike the N-category (Not resistant to oil) and the R-category (Resistant to cU). they may be used for longer than one work shift. Ho wever, air sampling to date has not identified an oil aerosol concern For tha reason given below, WTC workers should discard respirator caru-idges at the end of each work- shift. Thus, N- and R-category particulate filters could also be used.

Organic vapor and acid gas

Combustion byproducts generated during fires are known to have a potential for containing organic vapors and acid gases. Because the actual gases and vapors as well as the. air concentrations encountered by workers can vary' with factors such as work location, tasks, duration, arid weather conditions, cartridges should be discarded aller a work shift.

September 28, 2001

SSP.28'01 (FSI) 11.20 COMMUNICATION Ns .44 ?AOE. 2

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