|1. Obtain the following information:
- names of all airborne contaminants
- breathing rate of workers or;
- maximum flow rate of powered air purifying respirator
- estimate of worst case exposure levels
|Carl is part owner of a carpet manufacturing
plant where a third of the employees wear full mask respirators to protect them from
trichloroethylene. They are changing the respirator cartridges about every two hours
based on an estimate using a math model. Carl believes the cartridges probably have
a longer service life and would like to have more accurate, experimental tests
performed. Because some of the workers perform extremely physical tasks on a regular
basis, Carl has identified the breathing rate as very high.
|2. Determine who will conduct the experimental tests.
- Your company's Industrial Hygienist
- An outside consultant or laboratory
| Carl recently contacted a local certified analytical laboratory. He works out a deal with them to have the cartridges tested in their lab.
|3. Provide the tester with the following:
- information from step 1
- actual cartridges for the respirators
- the opportunity to test at the work site under typical conditions; or
- the range of variable factors or conditions to be given to the lab
|Carl visits the laboratory and gives some
cartridges and the existing data to the lab director, including the maximum relative
humidity of the work environment.
|4. Obtain the results and create
a written change schedule for the cartridges.
||Carl visited the lab some days later and was
pleased to find out that the cartridge protection actually lasted close to 4 hours before
the chemical broke through the cartridge! Carl multiplied a safety factor of 3/4 to
the estimate and set his change schedule at 3 hours. This meant that he could
purchase a third fewer cartridges. Carl took the lab reports and change
schedule and incorporated them into his written respirator program.