The Supreme Court Sick Building Mystery

None of the VOC concentrations measured in either the non-complaint area (Room 230) or the complaint areas of the sub-basement exceeded any OSHA Permissible Exposure Limits (PEL) or ACGIH Threshold Limit Values (TLV). No threshold limit has been established by OSHA or ACGIH for Hexanol or Heptanol. The ACGIH TLV 8-hour Time Weighted Average (TWA) for Cyclopentasiloxane, decamethyl is 5,000 ppb (~76,600 ug/m3). OSHA PELs and ACGIH TLVs are typically set at concentrations well below those believed by the regulatory and scientific bodies to cause acute or chronic illness.

Since carpet removal was completed, approximately 1-year before the final VOC test, concentrations of indicator VOCs and TVOCs had reduced. Little guidance is provided by occupational health agencies or researchers on exposure limits to a combination of chemicals at these low concentrations. However, by examining samples collected in the Florida Supreme Court using consistent methods and analyses an estimated threshold limit for indicator VOCs can be empirically derived to aid in decision making. By examining indicator VOC concentrations found in the non-complaint area (Room 230) that was sampled on 3/25/2004 and again on 7/7/2005 and in areas of the sub-basement where odors and irritant complaints were not reported, acceptable concentration values were estimated. Indicator VOC concentrations measured in a number of complaint offices were used to estimate concentration values that prompted occupant complaints of odor and upper airway and eye irritation.

Indicator VOC concentrations from areas that were sampled specifically because no odors or irritant complaints were identified by occupants included the JDC Site 2 (South end of hallway) on 6/24/2003; Room 230 on 3/25/2004; and Room 230 on 7/7/2005. The indicator VOC concentrations measured during these tests were 4.5 ug/m3, 18.6ug/m3, and 5.7 ug/m3 respectively. Utilizing these data we can state that when indicator VOC concentrations were below 20 ug/m3 no complaints of odors or respiratory irritation were reported by building occupants.

Examination of sample results for indicator VOCs in complaint areas reveal the concentrations ranged from 199 to 22.7 ug/m3 before carpet removal. After carpet removal occurred concentrations of indicator VOCs dropped in the areas adjacent to the JDC, where carpet had not been removed.This finding suggests the source of indicator VOCs was the carpeting in the JDC. Concerns by building occupants that carpet backing in the Family Courts and Office of Courts Improvement areas was also degrading and emitting irritant VOCs is not supported by these findings. Indicator VOC concentrations of 22.7 ug/m3 were found in samples taken in Room 146 on 3/25/2004, suggesting that 20 ug/m3 may serve as an indicator threshold for occupant odor or irritant reactions in this building.

Concentrations of indicator VOCs in samples collected from the JDC area on 7/7/2005 ranged from 9.9 to 14.9 ug/m3. In the adjacent offices that had previously reported odors and irritant effects (Rooms 136 and 141-C) concentrations of indicator VOCs were 3.2 and 3.3 ug/m3, respectively.

Room 230, the non-complaint area had indicator VOC concentrations of 5.7 ug/m3. These findings demonstrate that concentrations of the indicator VOCs have continued to drop after the removal of carpeting from the JDC. They also suggest that concentrations of indicator VOCs in the JDC have fallen below the levels previously found in the non-complaint area of Room 230.

These data demonstrate that further reductions of indicator VOCs could still occur in the JDC, when compared to concurrent samples taken in other areas of the sub-basement and basement level.Background concentrations of indicator VOCs in areas of the building where no odors or complaints were reported ranged from 3.2 to 18.6 ug/m3. Even though concentrations of indicator VOCs in the JDC were found to be slightly elevated on 7/7/2005 above those found in other areas of the sub-basement and the non-complaint room, they were below the concentration that was measured in the non-complaint room 230 on 3/24/2004 (See Figure on Page 9). Since the concentration of indicator VOCs in the JDC have fallen below the level found in a non-complaint area of the building, re-occupancy of the JDC should be possible. This trend in measured indicator VOC concentrations suggests that occupant exposure to the indicator VOCs in the JDC would be less than that experienced in the non-complaint room during March 2004. Choices of new flooring in the JDC should be based on measured moisture emission rates through the slab.