SAFETY SOLUTIONS: Indoor Air Quality
Has an employee ever walked into your office and complained that the air they breathe is making them sick? Is the air making them sick or is this just something new to complain about? What should you do?
Indoor Air Quality Warning Signs (IAQ Symptoms)
Headache, eye, nose or throat irritation
¨Dry or itchy skin
¨Dizziness and nausea
¨Difficulty concentrating, fatigue
¨Sensitivity to odors
Before you call in a professional, there are a few simple things that you and your staff can do.
To prepare for a walkthrough inspection, know the history of the building, review the HVAC zones and complaint areas. Communicate with affected employees.
An easy way to see where the air is coming from is to place a tissue in front of a door. Open the door slightly. Watch the way the tissue flows. Is the air coming in or going out? If you’d like to be slightly more technical, invest in a ventilation smoke tube test kit (available from Granger for $85.00). This can help you determine the velocity, direction and flow of slow moving air current. You follow the direction of the controlled smoke.
If the airflow is coming in through an outside door, you could be bringing in exhaust from outside traffic, a parking lot or loading dock. Or you could be bringing in the exhaust from a neighboring manufacturing facility. If the airflow is traveling to the outdoors, you are bringing your air in from somewhere else. Hopefully, it is being supplied by a central air handling system so that it can be filtered prior to distribution through the work area. Some employees believe opening a window brings in "fresh air," however, air from the air handling system should be cleaner.
The airflow could be coming from your manufacturing area to the office area. Ideally, the office air-handling unit should be separate from the manufacturing area. Again, make sure you are bringing in enough fresh air from the office air handler so that air flows from the office into the manufacturing area, NOT from the manufacturing area into the office.
In the manufacturing area, you want to have the air flow in the direction of cleanest process to dirtiest process. Where there is a chemical application such as painting, use local exhaust.
If I Can Smell It, It Must Be Bad
An employee called me in a panic. She smelled smoke. Her eyes were watering and she had difficulty breathing. I immediately investigated the concern. After walking through the facility without success, I walked around the property. Someone was burning a pile of leaves down the street. Not exactly the health dilemma I feared.
Employees often associated "smell" with hazard. As soon as they can smell it, they believe they are experiencing health hazards. Many chemicals have a low odor threshold and are not harmful until the levels are much higher. Other chemicals can have a negative health impact prior to them being detectable by smell.
Employees want you to be able to run to their workspace; turn on a magical meter and tell them exactly what chemical is leaching out. Unfortunately, this technology does not exist. Try your best to calm them. Only an industrial hygienist can sample for levels of specific chemicals.
High Risk Employees
A building engineer complained about the air quality in his office. After investigating what seemed to be acceptable air quality we discovered the only air intake into the custodial office was via the boiler room. This employee was very allergic to boiler chemicals. He was probably reacting to a low concentration of boiler chemicals. We added a fresh air intake to his office and viola! - improved health.
While the air may seem fine to you, employees with allergies, asthma and those whose health is impaired are more susceptible to IAQ issues. Just because they are the only person with symptoms does not mean there is no problem.
Of course, if multiple people are having similar symptoms, this may help you confirm there is an IAQ problem.
An employee was sick of being sick. He was fine at home and as soon as he got to work he was sick. I began the IAQ investigation by measuring airflow and investigating for mold. Next, I interviewed the employee and found he was highly allergic to cats and dogs. There were no animals in the building; however, the employee that worked next to him had four cats.
It is estimated that 70% of our homes have a furry pet. Employees carry pet dander in to the workplace on their clothes, which can cause their co-workers to feel very sick at work.
There are a few ways to manage pet dander. First, make sure the floors are being cleaned daily. Pet dander is a very small particle so you need to use a HEPA filter vacuum. Second, you may want to remove the carpeting from that work area and replace with hard flooring. If the sick employee does not improve, try segregating the employees' office areas.
Carpet is comfortable, attractive and alleviates foot traffic noise. Carpet can also be a sinkhole for spores, animal dander and dust mites. New carpet and glue can contain volatile organic compounds (VOC's), which can emit gas. Carpet that is older and deteriorating can also cause indoor air quality problems.
When carpet is installed in any part of the building, it must be properly maintained. It should be vacuumed often with a HEPA filter vacuum and professionally cleaned based on its construction, type and frequency of traffic and soiling conditions encountered.
Because of recent media coverage, many employees that have IAQ concerns believe there could be mold growing behind the walls or carpet. Again, you need to calm your employees. There is no list of known "toxic" molds and no data as to the concentration of mold growth that impacts your health. A common sense approach to mold investigation is:
Can you smell it?
Can you see it?
If you can't see or smell it; you probably do not have it.
In order for mold to grow, there must be a water source present. As soon as there is ANY water intrusion into the facility, the problem should be corrected and wet areas dried immediately.
There are many different types of air filters available. Particle filters trap the "boulders" and allow for maximum air movement. HEPA filters capture small particles including bacteria, viruses and mold spores but are expensive and limit air movement. Filters must be the correct size and be installed correctly to work properly. Contact a professional filter supplier to review your filter needs. Your building maintenance employee should be trained on when and how to change them.
Pollutant Source Removal or Modification
¨Replace water-stained ceiling tiles.
¨Assure carpeting is dry and well maintained.
¨Implement a non-smoking policy
¨Vent contaminants outdoors.
¨Make sure that air intakes are located from air exhaust or other pollutant sources.
¨Properly store chemicals.
¨Minimize the use of pesticides.
¨Allow materials, such as carpet, to off-gas before occupancy.
Increase Ventilation Rates and Air Distribution
Meet with an HVAC contractor to determine if your HVAC system is working as designed and within The American Society of Heating, Refrigerating and Air Conditioning Engineers (ASHRAE) standards.
Make sure HVAC system is well maintained including thorough annual cleaning and maintenance.
Every manufacturing facility should hire an industrial hygienist to obtain a baseline of the chemical levels in the manufacturing area prior to an "emergency".
Many employees confuse air quality with air comfort. If they feel the temperature or humidity is uncomfortable they believe they have poor IAQ. It is a valid concern since Americans spend 90% of their day indoors.
Energy efficient environments that reduce drafts, air leaks and closer proximity to synthetic products have increased the levels of known carcinogens in the environment.
Monitoring and maintaining acceptable indoor air quality is now more important than ever before.
Guest written by Denise Sundquist, M.S., ASP, the Indoor Air Quality Coordinator for the Brainerd School District in Brainerd, MN. She has also taught ventilation, industrial hygiene and health & safety courses at Central Lakes College.
For more information, click on the Author Biography link at the top of this page.