Health hazard evaluation report: HETA-2000-0169-2854, Riverside County Regional Medical Center, Riverside, California.
In March 2000, the National Institute for Occupational Safety and Health (NIOSH) received a request from the Service Employees International Union (SEIU) local 1997 to conduct a health hazard evaluation (HHE) at Riverside County Regional Medical Center in Riverside, California. NIOSH was asked to evaluate potential exposures to 2-diethylaminoethanol (DEAE) in patient care areas of the hospital that were humidified. While at work some hospital employees experienced dry cough, sneezing, wheezing, tearing of the eyes, headaches, skin irritation, and asthma, which they believed to be caused by exposures to DEAE in the workplace air. Steam, delivered from hot water boilers containing DEAE (a corrosion inhibitor), is used to increase humidity in several patient care areas of the hospital. Most rooms humidified in these areas were isolation rooms, recovery rooms, and operating rooms (OR). The hospital's air quality was reportedly being affected by diesel exhaust that entered the ventilation system from diesel-powered generators. On May 2-4, 2000, NIOSH investigators made a site visit to the hospital to inspect the heating, ventilating, and air-conditioning (HVAC) system, collect air samples and surface wipe samples for DEAE in humidified areas, and measure temperature and relative humidity. Two unoccupied isolation rooms in the ACCU were used to evaluate the highest possible DEAE concentrations generated when humidity levels were increased to up to 55%. None of the 34 air samples had detectable amounts of DEAE (the minimum detectable concentration [MDC] was 0.02 parts per million [ppm] for the sample set). Three of 14 wipe samples revealed the presence of trace amounts of DEAE on ceiling diffusers located in the NICU and the two isolation rooms in the ACCU, suggesting that DEAE was being delivered to these areas. All other wipe samples showed no DEAE. Temperature and relative humidity in patient care areas were within the acceptable range recommended by the American Society for Refrigeration and Heating Engineers(ASHRAE). During the site visit confidential interviews were conducted with 41 employees. The most prevalent symptoms included: irritated eyes-10 employees (including tearing and burning of the eye), nasal symptoms -9 employees, skin irritation-7 employees, increased allergies (itchy skin, sneezing, and tearing eyes)-5 employees, and headache-3 employees. Six employees had no symptoms that they attributed to the workplace. Interviewed employees were self-selected, however, and there was no evidence that the symptom prevalence was greater in the hospital than in other work settings in California. Based on the air sampling results for this HHE, there is insufficient data to positively link DEAE exposure with reported symptoms. However, although no detectable air concentrations of DEAE were measured, employees reported symptoms that were consistent with exposure to DEAE, as reported in other NIOSH studies. NIOSH investigators recommend that humidification with boiler steam containing DEAE be discontinued. Other suggestions to improve indoor environmental quality and worker health and safety are offered in the Recommendations section of this report.