Page 85 - Occupational Health & Safety, September 2019

air intake during heating season could increase carbon monoxide levels if the heating unit is not properly vented and maintained.
Silent and Deadly
Carbon monoxide exposure can be a silent and deadly killer, aris- ing from sources of combustion including improperly ventilated and/or maintained gas fired furnaces/boilers/space heaters and hot water heaters.
Incidents investigated or researched in the past included high- and low-rise office buildings (HVAC), restaurants and commercial facility hot water heaters, residences, and industrial warehouse heaters, and forklifts. These incidents resulted in death, hospital- ization, and ill health. A certificate of occupancy IAQ monitoring consultation and/or annual professional inspection would have prevented these building incidents.
Many states now require carbon monoxide detection for com- mercial occupancies and restaurants, in addition to residences. It is important that occupancy staff are informed of the detection systems and that they should take alarm conditions seriously. In- cident investigation has determined that the detection systems are sometimes turned off during true emergencies due to an incorrect perception of “false alarms.” These detection and alarm systems should also be regularly tested.
Temperature
Temperature issues are the most frequent IAQ complaint and can be complicated by numerous unlocked and accessible thermostats, variable air volume air distribution controls, supply vent damper levers, and diverse occupant temperature preferences. When faced with the reality that there is not one temperature that will make all occupants happy, ASHRAE Standard 55 Thermal Environmental Conditions for Human Occupancy sets suggested seasonal tem- perature and humidity ranges. The implementation of these ranges with locking thermostats dramatically reduces recurring tempera- ture complaints.
IAQ Investigations
Indoor air quality investigations should be completed during nor- mal occupancy hours. It is important that results be accurate and that political fears for investigation visibility or new claims genera- tion be calmed. Attending to occupant complaints is a responsive safety “best practice.”
The assessment should include occupant and complainant in- terviews, symptom “location heat mapping,” time of day and any weather-related variables, odors or visible contamination, and air quality monitoring.
The roof should be safely accessed if HVAC roof units exist
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