Respirator Cartridge Change Schedules
Forensic Analytical Consulting Services, February 24, 2009

• Are you adequately protecting workers from chemical hazards in the workplace?
• Are you meeting OSHA respirator program requirements? 
• Are you subject to a potential citation and / or fine?

Forensic Analytical has received numerous calls inquiring about cartridge service lives.   As a service to our clients please find the summary below on the various requirements for employers.

Requirements:

The following is a summary of the pertinent requirements of the standard (29 CFR 1910.134(d)(3)(iii)(B)(2) regarding change schedules.:

• Employers must develop cartridge/canister change schedules based on available data or information. Such information includes the exposure assessment and information based on breakthrough test data, mathematically based estimates, and/or reliable use recommendations from the employer's respirator and/or chemical suppliers.
• Reliance on odor thresholds and other warning properties will not be permitted as the primary basis for determining the service life of gas and vapor cartridges and canisters.
• OSHA emphasizes that a conservative approach is recommended when evaluating service life testing data. Temperature, humidity, air flow through the filter, the work rate, and the presence of other potential interfering chemicals in the workplace all can have a serious effect on the service life of an air-purifying cartridge or canister.

There are three valid ways for you to estimate a cartridge's service life:

1. Experimental Testing – Most accurate but may be time consuming and costly

2. Manufacturer’s recommendation – Most manufacturers have software tools for this purpose.  Links to tools for three popular brands of respirator are:

            3M

            MSA

            North Safety

3. Mathematical Model – Least accurate method and generally limited to a single contaminant

Recommendations:

Forensic Analytical recommends reviewing your respiratory protection program to assure that cartridge change schedules are included and appropriate for the hazards.  Use one of the methods listed above to estimate the cartridge lives. 

Of course just having access to the various tools noted above is not sufficient in determining service life.  The employer must know a few things first:

• Contaminants of concern
• Actual exposure concentrations
• Work rates
• Environmental conditions: temperature, relative humidity, atmospheric pressure
• Appropriate safety factors to account for the following:

à    Accuracy of workplace concentration estimates,

à    The presence of other organic vapors;

à    Relative humidity greater than 65%; and

à    Warning properties of the contaminant.

Forensic Analytical Services

Forensic Analytical assists clients in avoiding costly OSHA citations and most importantly, providing a healthful working environment for their employees. Some of our services include:

1. Review of MSDS and site work to determine contaminants of concern, potential chemical interactions, and work rates.
2. Conducting exposure assessments including measurement of contaminant concentration as well as working temperatures, RH, and pressures.
3. Assisting in determining appropriate safety factors
4. Reviewing and editing respirator protection programs to assure they meet all OSHA criteria and requirements.

In addition, Forensic Analytical can provide affordable quantitative fit testing using the latest technologies.  Quantitative fit testing gives objective fit testing results with actual fit factors to provide added protection and documentation.

Some additional resources which may be useful:

• OSHA eTool:  http://www.osha.gov/SLTC/etools/respiratory/change_schedule.html

We are standing by to provide our services as needed or to simply answer your questions. Please do not hesitate to contact us for assistance.