Reprinted from the ACJ - January, 1993
The winter months are upon us again. Thoughts of scorching temperatures causing radiators to overheat have given way to thoughts of Arctic cold causing radiators to freeze.
In the shop, similar seasonal changes occur. Everyone screams expletives each time the garage door is opened to bring a car in or out, and you start to look at the boilout tank as a possible Jacuzzi. The cold outside causes us to close ourselves inside and trapped with us are the fumes generated during a day of service work.
OSHA requires shop owners to provide respiratory protection for their employees and provides a set of rules to follow, 29CFR 1910.134. OSHA favors ventilation wherever possible, but even adequate ventilation cannot circulate the air in the shop like the open garage doors do in the summer, so extra protection is sometimes necessary.
Respirators are the easiest way to avoid inhalation dangers. Their use and care is this month's topic of discussion.
We first have to determine if respiratory protection is necessary. The way to find out is through air monitoring. The monitoring you did for lead exposure is a good starting point.
Another way to test air quality, especially for corrosive vapors and paint fumes, is the use of "Drager Tubes." These are small glass tubes filled with chemicals that change color as fumes are drawn through them, indicating the concentration of the chemical being tested. Most safety companies sell them. They are very easy to use and will give you a fume level in specific areas such as over your boilout tank or in your paint booth, areas where increased respiratory protection may be needed.
If the measured level is above the Threshold Exposure Limit Value (TLV or PEL) listed on the Material Safety Data Sheet (MSDS), extra protection is necessary. A rule of thumb is that air purifying respirators are effective at fume levels up to 10 times the TLV-PEL. Fume levels higher than that require mechanical ventilation.
After determining that respirators are needed, choosing the right one is the next step. Respirators come in two basic types: atmosphere supplying and air purifying. Supply types come with a bottle of air like scuba diving units and are a bit of overkill for our purposes.
Purifying units work to clean the shop air before we breathe it. Their cleansing action can be mechanical, like dust masks or the bandanna worn in cowboy movies, or they can be a chemical that traps the toxic vapors before we breathe them.
We will concentrate on the chemical type air purifying units. These units are made up of two parts: the mask which covers your mouth and nose (it may be an entire face shield), and the fume-trapping cartridges that screw or pop on the mask. When purchasing units, make sure all respirator parts and cartridges carry NIOSH (National Institute for Occupational Safety and Health) approval.
The cartridges are of various types and are classified according to the fumes they screen. Those cowboy bandannas worked well for trail dust, but not for the fumes inside the barn. NIOSH cartridges are color coded according to the fume type for which they are effective.
A basic guideline for radiator shops may include the following:
• Zinc chloride fluxes give off acid and ammonia type fumes. A green cartridge with a white stripe captures these fumes.
• Organic type fluxes generate both organic vapors and acid fumes. Yellow cartridges capture these.
• Straight organic fumes like paint or fuel tank liner require a black cartridge.
Adding a High Efficiency Particulate (HEPA) filter on top of any of these cartridges will filter lead dust and fumes.
Now that you have the proper respirator, you have to make sure your employee is able to wear and benefit from them. OSHA requires a physical examination of the employee to test cardiovascular ability and a check of their medical history in order to be certain the employee won't have any problems breathing through the respirator.
When the respirator is correct and the wearer has been fit tested, it is time to instruct him or her in the proper use and care of the unit. Proper fit is a simple task. When on the face, the only air the wearer gets should come through the cartridges. Otherwise, they are still breathing dirty air and walking around looking like Darth Vader from "Star Wars" for no good reason. Long sideburns, beards or bushy mustaches will prevent the mask from sealing tightly on your face and should be trimmed or shaved off. I know this will anger some folks, but it really is crucial.
OSHA's guidelines give a procedure to check if the respirator is properly fit and functioning. I would like to add a simple test to be used every time you put on a respirator. Place your hands over the cartridges, sealing them off. Don't press too hard because you want the mask to hold itself on without your help. Then breathe in. If air enters, it is bypassing the cartridges and that needs to be remedied.
It may be just tightening the straps, fixing an exhale valve or (dare I say it again) shaving facial hair. If no air enters and your inhalation creates a vacuum in the mask, then you will be filtering the fumes properly and are protected.
It is best to have a separate respirator for each employee. No one likes to breath someone else's air. Besides, if one guy gets a cold, a community respirator guarantees an epidemic in the shop.
Proper storage and cleaning are necessary skills each employee needs to know. Respirators are
not very comfortable and sweating inside them is common. Cleaning the respirator face mask is as easy as an occasional soap and water bath after removing the cartridges to keep them dry. That is also a good time to inspect the unit for ripped valves, worn seals or bad straps, etc.
Disinfecting with bleach once in a while is also helpful, especially during flu and cold season. Storing the respirator in a plastic bag is the best way to avoid contamination. Keeping it in your locker will help as well.
Leaving a respirator uncovered in the shop allows dust and fumes to line the inside. The next time you put it on, you are breathing those fumes and dust over and over. It can be worse than no respirator at all.
Changing cartridges should be done periodically or anytime the wearer can smell the fumes through the unit.
Usually people who know why a respirator is necessary and how to care for it are going to want to protect themselves. Therefore, a respirator program is easy to implement and appreciated by the employees. OSHA likes written plans, so document your work; determining the hazard, physical testing, use and care, etc.
Using this common sense approach will keep your employees and yourself safe and healthy. It will also go a long way toward satisfying OSHA's respiratory protection program requirements. Besides, those expletives everyone yells when the garage door is opened are not as nasty when muffled through a respirator.
The above article was written by David M. Brown, Chief Engineer of Johnson Manufacturing Company, Inc. and is published by JOHNSON with the expressed approval of the National Automotive Radiator Service Association and the Automotive Cooling Journal. Other reproduction or distribution of this information is forbidden without the written consent of JOHNSON and NARSA/ACJ. All rights reserved.
JOHNSON MANUFACTURING COMPANY
114 Lost Grove Road / PO Box 96 / Princeton, Iowa 52768-0096
Phone 563-289-5123 or Fax 563-289-3825