EPA interim final report on WTC background study, April 2003

NYC 9/11 Public Portal Document

Table 8. Fibrous Glass

Tier Action Fibrous Glass (settled dust) Fibrous Glass (indoor air) Level Basis Level Basis I Aggressive cleaning. > 100,000 Millette’s K >0.1 fZcc ACGIH TLV of If levels persist, take f/cm^ factor to estimate 1 f/cc (see additional action to airborne levels for narrative below). reduce exposure. different activities (see narrative Evaluate conditions in below). the area including representativeness of air samples, fibrous glass settled dust levels and loading. n Maintain 100,000 0.01 to 0.1 recommended f/cm^ to f/cc cleaning methods. background Consider additional monitoring.

Evaluate conditions in the area including representativeness of air samples, fibrous glass settled dust levels and loading. in No further action background Level is set at that < 0.01 f/cc ACGIH TLV of required found in 1 f/cc (see background, or narrative below) imaffected, areas. In this way, no increase in risk due to the fibers would be expected. * Fibers with length > 5pm with an aspect ratio > 3:1, as defined in the ACGIH TLV. Air concentrations measured by PCM, NIOSH 7400, confirmed by SEM.

The benchmarks for airborne fibrous glass were set based on the consideration that low level exposures to fibrous glass would not pose the potential for significant long-term health effects given the expected low biopersistence of these materials [ATSDR, 2002]. The current occupational exposure standards for fibrous glass (glass and mineral wools) is established to prevent the upper respiratory tract and skin irritant effects. In order to apply this standard to a general population and accounting for a longer daily exposure than seen in the occupation

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