Strategy for Exposure Assessment
Personnel Information
Exposure Assessments will be performed for all work groups at a location, including office / administration personnel. Begin by developing a list of Job Titles and Work Areas at the site. You will also need to develop or obtain a Task List, the set of operations or tasks performed by each work group.
Based on the above information, the goal is to organize the workforce into what is termed Similar Exposure Groups (SEGs). Depending on how your facility operates, similar exposure groups may be established by Job Title, by Work Area (if the group does not move between work areas), or you may need both Job Title and Work Area to establish unique similar exposure groups, for example where many workers share the same job title and many groups work in one area.
It may be necessary to refine an existing job title to adequately define a unique set of exposures; however this practice should be avoided if at all possible.
An employee may be the sole member of a group if the exposure potential is unique and no others perform the same tasks. In other cases such as administrative personnel, it may be possible to profile multiple Job Titles within one SEG.
Health Hazard Information
Obtain the listing of substances used by the group in the work area that is the basis for the Hazard Communications program. An MSDS for each material must be available as well, and will be needed to identify components of mixtures.
Add the following to the list of substances from above when applicable to the work area/job:
• Component(s) of the material (if they have recognized exposure limits, TLV, PEL, BEI, WEEL or validated manufacturer limits. Use the last 2 only if the first 2 are not available.)
• Heat Stress
• Cold Stress
• Radiation, ionizing or non-ionizing (level / flow meters, microwaves, uv systems, tritium exit signs, radios, magnetic fields, x-rays, lab equipment)
• Insulation materials (asbestos, fiberglass etc.)
• PCB's
• Welding, burning fumes
• Noise
• Vibration
• Exhaust Gases
• Nuisance Particulates
• Illumination Hazards
• Biological Hazards ( legionella and other cooling water hazards, bird / animal hazards, insects, plants, molds, bio-activated waste treatment systems, Bloodborne pathogen hazards, sanitary waste systems )
• Fatigue / metabolic rhythm issues
• Building air quality issues ( eg CO, CO2, relative humidity, off-gas chemicals from carpets/ insulation )
Interview supervisors and employees from the Similar Exposure Group (SEG) and complete the Job Exposure Profile form, with prioritization calculations for each item of the listing. The method for completing the form is described below.
Use the prioritization ratings to determine which items will require monitoring, further evaluation or corrective action.
Summarize the results or the assessment for each group and the prioritization of monitoring
Review the results with plant management and provide a copy to the site Medical Contact.
FORM: INSTRUCTIONS
In the header section of the form, define and record the major identifiers (Job Title and/or Work Area) and a general description of the work performed by the group, general information about exposures / controls and work hours / schedules. This description defines this SEG Similar Exposure Group.
Task: The purpose of this field is to identify when, during the work shift, exposure to chemicals or physical agents occur.
Where exposure to a chemical/agent occurs over several operations or a significant portion of the work shift, and/or the chemical/agent has a TWA exposure limit, enter "general duties" in the task field. When exposure is limited to a single task/operation, or the chemical has a STEL or Ceiling exposure limit, or the chemical is identified as irritating/corrosive on the MSDS, identify the specific task(s) where exposure occurs. For chemicals with STEL or Ceiling exposure limits, or where identified as irritating/corrosive on the MSDS, list all tasks where it is necessary to evaluate exposure. Please note that based on the above criteria, some chemicals may require several entries as illustrated in the following example:
General Duties Ammonia (evaluate general background levels compared to TWA)
Drum Fill Ammonia (evaluate potentially higher exposures in this task to STEL)
Sampling Ammonia (evaluate potentially higher exposures in this task to STEL)
Chemical/Agent
Enter the name of the chemical/agent for which exposure is being evaluated. In some cases this may be an ingredient or generic name of the actual material you are using in other cases you may be able to combine several materials under one listing. Here are some examples:
Product XYZ contains Sodium Hydroxide, list Sodium Hydroxide as the chemical, you must identify that it came from XYZ in the comments field below the listing
Cellulose fillers, calcium carbonate, other generally non-hazardous dust producing materials may be combined under the chemical name nuisance dust. (Remember that you may have to differentiate total vs. respirable nuisance dust). Specific chemicals/products that contribute to the nuisance dust listing must be referenced in the comments field below the listing.
Some chemicals have group exposure limits, for example organotins, insoluble chrome VI compounds. Use these designations as the chemical name. Specific chemicals that contribute to the group listing must be referenced in the comments field below the listing.
Exposure Limit Type
Enter the applicable Exposure Limit Type (TWA= Time Weighted Average, C= Ceiling, STEL = Short Term Exposure Limit, BEI= Biological Exposure Indices, WBGT= Wet Bulb Globe Temperature) and also identify the source agency (OSHA, ACGIH, AIHA, Manufacturer Recommendations). If multiple agencies have limits for the chemical, use the lowest value. Remember to have at least one listing for each exposure limit type as shown in the example above.
If no limits are specified, assume TWA unless MSDS states the material is irritating/corrosive. Also list "No Agency".
Physical State
Identify the physical state of a chemical as liquid, solid, mist, vapor, fume, aerosol, or gas. This is helpful in investigating an employee exposure. The same chemical could be present in 2 different forms, and may require a multiple listings if exposure potential varies with form. It may also require a different type of sampling.
Skin Contact Y/N
If there is a possibility for a skin exposure to a chemical, enter "Y" for yes under the column. This will help with the PPE assessments.
Information contained in the Job Exposure Profile is used to develop a formula for prioritizing follow-up monitoring and assessment requirements. The priority value is based on the multiplication of values from fields: Exposure Level, Frequency, Degree of Engineering Controls, Last Sample Date and Health Effects. Values for each of these fields are assigned as follows.
a. Exposure Level
20 = Measured value above the Exposure Limit
5 = For materials where no sampling has been performed, and qualitative factors can not been determined.
4 = For materials where previous monitoring shows some results above 80% of the applicable exposure limit or liquid with a vapor pressure of 150 mmHg or more, or the material has a heavy odor, or heavy visible dust, mist or fume is present. For noise, there is difficulty in conversation at 5 feet. For heat, there is significant perspiration even during winter months.
3 = For materials where some previous monitoring from 50% to 80% of the applicable exposure limit or liquid with a vapor pressure of 100 to 149 mmHg, or the material has a moderate odor, or moderate visible dust, mist or fume is present. For noise, there is some difficulty in conversation at 5 feet. For heat, there is significant perspiration even during spring/fall months.
2 = For materials where previous monitoring from 10% to 50% of the applicable exposure limit or liquid with a vapor pressure of 50 to 99 mmHg, or the material has a slight odor, or some visible dust, mist or fume is present. For noise, there is no difficulty in conversation at 5 feet. For heat, there is significant perspiration during summer months.
1 = For materials where previous monitoring results showed all results less than 10% of the applicable limit or liquid with a vapor pressure less than 50 mmHg, or a material with good warning properties cannot be seen in the air or noticed by odor. For noise, there is no difficulty in conversation at 10 feet. For heat there is no significant exertion related perspiration.
0 = For materials where previous monitoring has shown none detected or where employees have no contact at all. An example would be PCBs in a transformer.
Precautions
• Monitoring results are to be used only when a significant number of samples have been taken on positions in the similar exposure group being evaluated, on three or more unrelated days.
• Vapor pressure is to be used for materials which have little or no odor reported on the MSDS.
• Sensory judgment takes precedence over vapor pressure when odor and or visible dust, mist, or fume would make "Exposure Level" a larger number. For example, a cutting oil has a very low vapor pressure, but mist in the air is noticeably heavy: that would rate as a 4.
b. Frequency of Exposure
5 = Routine exposure (daily use, > or = 180 days per year)
4 = Frequent exposure (1 or 2 days weekly or for a short period daily, > 30 and < 179 days per year)
3 = Monthly or for a short period weekly (not exceeding 30 days per year)
2 = A few times a year (not exceeding 40 hours per year)
1 = Less than 10 hours exposure per year
c. Degree of Engineering Controls (Consider both inhalation and contact for skin notation chemicals)
5 = Open system or operation with no local exhaust ventilation and contact possible for skin notation chemicals
4 = Qualifier for 3 - not working within specification
3 = Operations conducted with local exhaust ventilation and limited contact possible for skin notation chemicals
2 = Qualifier for 1 - not working within specification
1 = Closed system or adequately functioning laboratory hood and no contact possible for skin notation chemicals
d. Last Sample Date
3 = >3 years since last monitoring
2 = between 2 and 3 years since last monitoring
1 = < 2 year since last monitoring
e. Health Effects
3 = If a Carcinogen (classified as an ACGIH A1, A2 or A3, IARC 1, 2A, or 2B group or by NTP), Teratogen, Sensitizer, Strong Irritant/Corrosive, or LD50 < 50mg/Kg
2 = TLV/PEL < or = either 10 ppm or 1 mg/m3, Mutagen, or moderate irritant or LD50 < 500 mg/Kg
1 = All other chemicals/agents
The Prioritization results (a x b x c x d x e) should be used to plan for future monitoring sessions.
The higher the number, the higher the priority is to address this exposure.
Optional Risk Assessment code for Respirators:
This optional tool can be used to assess the need for respirators in a stepwise manner or to provide a written justification for not using a respirator. The assessment will determine if exposure is below the OEL (Occupational Exposure Limit), using your JEP results. Respirator usage is required if exposures are determined to be over the OEL.
This tool will build a bridge between the JEP and the PPE matrix and provide a written assessment of the need for respirator usage.
Chemicals falling under an OSHA Substance specific standard must follow OSHA requirements for sampling and respirator usage.
Codes to justify a NEED for Respirator Usage: (A)
(A) All tasks with an exposure level above the OEL (section a, exposure level with value > 20) require the use of a respirator, code A. Use "Selection of Respirator" flowchart to determine level of protection and type of media required.
Codes to justify NO NEED for Respirator Usage when sampling results are available: (B) and (C)
(B) All tasks that have sampling data (section d, Last sample Date, with value 1 or 2) and exposure level (section a, exposure level) is 3 or below, exposure is below OEL, no need for respirator usage, code B.
(C) If exposure level value is 4 (80% of OEL), insure exposure information is statistically significant. This means there are 7 - 9 samples for the task and a statistical package (such as Logan) has been used to verified their significance. If this has not been done, contact corporate IH for assistance. If statistically significant, no need for respirator, code C.
Codes to justify NO NEED for Respirator Usage when NO sampling data is required:
(D) If the section d, Last Sampling Date, is blank (no sampling data exist) and the chemical does NOT have a STEL or Ceiling limit (info on JEP under the Exposure Limit Type column), the exposure is brief (< 1 hour/day), and the Health Effect rating = 1, assume under full shift OEL. No respirator is required, code D.
Code when further evaluation is needed:
(E) All tasks which have not received one of the previous codes will be place on the "To be Evaluated" list, code E. These exposures have to be evaluated by more sampling or by the use of professional judgment. Sampling: Exposure level 4 or 5: Collect additional data to determine if a respirator is needed.
-You will need 1 to 3 samples if all the results are < 10% OEL.
-You will need 4 to 7 samples if all the results are > 10% OEL, but < 100% OEL.
-If more than one sample result is > OEL, make the Exposure Level code a 20.
Professional judgment: Document it in writing using a PPE assessment tool. Make sure you link the task ID (numbering, name, etc.) between your JEP and your written assessment document.
Comments: Below each exposure assessment line is space to enter comments. Comments could include information on the amount or frequency of material use, source process or material, specific sampling instructions, raw material number, exposure levels, or any other information.