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ESH Manual Page: 4000: Industrial Hygiene

It is the policy of Sanford Underground Laboratory at Homestake (otherwise known as “Sanford Laboratory”) that all employees, contractors, scientist and visitor will not be knowingly exposed to potentially hazardous atmospheres. .  The guidelines in this program are designed to help reduce employee exposure against occupational dusts, fogs, fumes, mists; radionuclide’s, smokes, sprays, gases and vapors.  The primary objective is to prevent excessive exposure to these contaminants. This is accomplished as far as feasible by accepted engineering and work practice control measures.  When effective engineering controls are not feasible, or while they are being implemented or evaluated, respiratory protection may be required to achieve this goal.  In these situations, respiratory protection, training and medical evaluations are provided at no cost to the employees.  


This program applies to all employees, contractors, scientists, vendors, and visitors (otherwise known as ‘Laboratory Personnel’) who may be exposed to respiratory hazards requiring the use of respiratory protection as a feasible control method.  


3.1. EHS Department

The EHS Department is responsible for:

  • Revising the respiratory protection program as needed;
  • Developing respiratory protection training;
  • Working with appropriate staff to identify respiratory hazards, ensure proper testing & training is conducted, and establish appropriate controls; and
  • Identifying appropriate medical monitoring providers for any necessary medical exams.

3.2. Industrial Health (IH) /Safety Technician The IH/Safety Technician is responsible for:

  • Performing or overseeing air testing; 
  • Notifying supervisors and personnel of monitoring results; 
  • Verifying that added controls are sufficient to reduce exposure below OEL limits;
  • Recommending controls to respiratory hazards; 
  • Recommending warning signs where appropriate; 
  • Providing updated respiratory hazard information for site-specific training; and
  • Reviewing plans for new operations and significant changes to ongoing operations that may create respiratory hazards.  

3.3. Laboratory Personnel
All Laboratory Personnel are responsible for: 

  • Completing required training in respiratory hazards and respiratory protection usage before working;
  • Receiving medical monitoring and sampling of work tasks as required;
  • Using controls, including  personal protective equipment provided; and
  • Reporting suspected exposures to supervisors, project managers, and/or to the EHS Department.

3.4. Project Managers
Project Managers are responsible for:

  • Reviewing proposed processes involving respiratory hazards with the EHS Department before installing new or moving existing equipment; 
  • Ensuring that contractors receive the proper medical evaluation, fit testing, and training on protective equipment;
  • Ensuring that contractors properly use, inspect, and maintain respiratory protection when required onsite;
  • Working in conjunction with various departments and the involved contractor(s) to ensure engineering controls are meeting minimum performance standards and effectively preventing personnel over-exposure to respiratory hazards; 
  • Reporting deficient engineering controls to the proper authority for repairs;
  • Following up on recommendations provided by the EHS department staff; 
  • Ensuring areas where respiratory hazards are found have the proper warning signs displayed, in consultation with the EHS department; 
  • Choosing less-hazardous design options whenever possible, in consultation with the EHS department; and
  • Including qualitative exposure assessment of respiratory hazards during the development and annual review of JHAs;

3.5. Supervisors
Supervisors are responsible for:

  • Reviewing proposed processes involving respiratory hazards with the EHS Department before installing new or moving existing equipment; 
  • Ensuring that workers under their supervision receive the proper medical evaluation, fit testing, and training on protective equipment;
  • Ensuring that workers under their supervision properly use, inspect, and maintain respiratory protection when required onsite;
  • Working in conjunction with various departments to ensure engineering controls are meeting minimum performance standards and effectively preventing personnel over-exposure to respiratory hazards; 
  • Reporting deficient engineering controls to the proper authority for repairs;
  • Following up on recommendations provided by the EHS department staff; 
  • Ensuring areas where respiratory hazards are found have the proper warning signs displayed, in consultation with the EHS department; 
  • Choosing less-hazardous design options whenever possible, in consultation with the EHS department; and
  • Including qualitative exposure assessment of respiratory hazards during the development and annual review of JHAs;

Air-purifying respirator: a respirator with an air purifying filter, cartridge, or canister that removes specific air contaminants by passing ambient air through the air-purifying element.
Atmosphere-supplying respirator: a respirator that supplies the respirator user with breathing air from a source independent of the ambient atmosphere, and includes supplied-air respirators (SARs) and self contained breathing apparatus (SCBA) units.

Canister or cartridge: a container with a filter, sorbent or catalyst, or combination of these items, which removes specific contaminations from the air passed through the container.

Demand respirator: an atmosphere-supplying respirator that admits breathing air to the facepiece only when a negative pressure is created inside the facepiece by inhalation.

Emergency situation: any occurrence such as, but not limited to, equipment failure, rupture of containers, or failure of control equipment that may or does result in an uncontrolled significant release of an airborne contaminant.

Employee exposure: exposure to a concentration of an airborne contaminant that would occur if the employee were not using respiratory protection.

End-of-service-life indicator (ESLI):  a system that warn the respirator user of the approach of the end of adequate respiratory protection, for example, that the sorbent is approaching saturation or is no longer effective.

Escape only respirator: a respirator intended to be used only for emergency exit.

Filter or air purifying elements: a component used in respirators to remove solid or liquid aerosols from the inspired air.

Filtering facepiece (dust mask): a negative pressure particulate respirator with a filter as an integral part of the facepiece or with the entire facepiece composed of the filtering medium.

Fit factor: a quantitative estimate of the fit of a particular respirator to a specific individual, and typically estimates the ratio of the concentration of a substance in ambient air to its concentration inside the respirator when worn.

Fit test: the use of a protocol to qualitative or quantitatively evaluate the fit of a respirator on an individual.  (See also Qualitative fit test QLFT and Quantitative fit test QNFT.)

Helmet: a rigid respiratory inlet covering that also provides head protection against impact and penetration.

High efficiency particulate air (HEPA) filter: a filter that is at least 99.97% efficient in removing monodisperse particles of 0.3 micrometers in diameter.  The equivalent NIOSH 42 CFR 84 particulate filters are the B100, and P100 filters.

Hood: a respiratory inlet covering that completely covers the head and neck and may also cover portions of the shoulders and torso.

IDLH –Immediately Dangerous To Life and Health

Immediately dangerous to life or health (IDLH): an atmosphere that poses an immediate threat to life, would cause irreversible adverse health effects, or would impair an individual=s ability to escape from a dangerous atmosphere.

Interior structural firefighting: the physical activity of fire suppression, rescue or both, inside of buildings or enclosed structures which are involved in a fire situation beyond the incipient stage.  (See 29 CFR 1910.155)

Loose-fitting facepiece: a respiratory inlet covering that is designed to form a partial seal with the face.

Negative pressure respirator (tight fitting): a respirator in which the air pressure inside the facepiece is negative during inhalation with respect to the ambient air pressure outside the respirator.
Oxygen deficient atmosphere means an atmosphere with oxygen content below 19.5% by volume.

Physician or other licensed health care professional (PLHCP): an individual whose legally permitted scope of practice (i.e., license, registration, or certification) allows him or her to independently provide, or be delegated the responsibility to provide, some or all of the health care services required by paragraph (e) 29 CFR 1910.134.

Positive pressure respirator: a respirator in which the pressure inside the respiratory inlet covering exceeds the ambient air pressure outside the respirator.

Powered air-purifying respirator (PAPR):  an air purifying respirator that used a blower to force the ambient air through air-purifying elements to the inlet covering.

Pressure demand respirator: a positive pressure atmosphere-supplying respirator that admits breathing air to the facepiece when the positive pressure is reduced inside the facepiece by inhalation.

Qualitative fit test (QLFT): a pass/fail test to assess the adequacy of respirator fit that relies on the individual’s response to the test agent.

Respiratory inlet covering: that portion of the respirator that forms the protective barrier between the user’s respiratory tract and an air-purifying device or breathing air source, or both.  It may be a facepiece, helmet, hood, suit, or a mouthpiece respirator with nose clamp.

Self-contained breathing apparatus (SCBA): an atmosphere-supplying respirator for which the breathing air source is designed to be carried by the user.

Service life means the period of time that a respirator, filter or sorbent or other respiratory equipment provides adequate protection to the wearer.

Supplied-air respirator (SAR) or airline respirator: an atmosphere-supplying respirator for which the source of breathing air is not designed to be carried by the user.

Tight-fitting facepiece: a respiratory inlet covering that forms a complete seal with the face.

User seal check: an action conducted by the respirator user to determine if the respirator is properly seated to the face.


Exposure evaluations will be performed initially and on a periodic basis to access the presence of respiratory hazards and to aid in proper respirator selection.  In order to determine exposure level, air samples of the work place representative of the work period; exposure assessment based on analogous processes; or professional judgment will be used.  Personal sampling equipment may be used in accordance with accepted industrial hygiene practice or standards to sample each work area.  Results of these samples will pinpoint areas where respiratory protection is required.

The exposure assessment will be performed prior to commencing any routine or non-routine task requiring respiratory protection.  Periodically thereafter as required by changing conditions, regulatory substance specific standards or every 12 months, a review of the exposure assessment will be made to determine if respiratory protection continues to be required.  If respiratory protection is still necessary, the previously chosen respirators will be reviewed to assure that they still provide adequate protection.

Records of all exposure assessments will be maintained by the EHS Department.


 Sanford Lab will select only respirators that are certified by the National Institute for Occupational Safety and Health (NIOSH) which must be used in compliance with the conditions of its certification.  Respirators will be selected and approved for use by management.  The selection will be based upon the physical and chemical properties of the air contaminants and the concentration level likely to be encountered by the employee.  The respirator program administrator will make a respirator available immediately to each employee who is placed as a new hire or a transferee to a job that requires respiratory protection.  Replacement respirators/cartridges and filters will be made available as required. Where exposure cannot be identified or reasonably estimated, the atmosphere shall be considered immediately dangerous to life or health (IDLH). 

Selection of all respirators will conform to the OSHA Assigned Protection Factors Table (APF, See Table 1.0) when sampling data is available upon respirator selection, or becomes available while the task is being performed.

Table 1.0—Assigned Protection Factors5

Type of respirator1,

Quarter mask 

Half mask 

Full facepiece 

Helmet/ hood 

Loose-fitting facepiece 

1. Air-Purifying Respirator 





2. Powered Air-Purifying Respirator (PAPR) 






3. Supplied-Air Respirator (SAR) or Airline Respirator

  • Demand mode
  • Continuous flow mode
  • Pressure-demand or other positive-pressure mode 











425/1,000 .............. 




4. Self-Contained Breathing Apparatus (SCBA)

  • Demand mode
  • Pressure-demand or other positive-pressure mode (e.g., open/closed circuit) 











Notes: 1Employers may select respirators assigned for use in higher workplace concentrations of a hazardous substance for use at lower concentrations of that substance, or when required respirator use is independent of concentration. 

2The assigned protection factors in Table 1 are only effective when the employer implements a continuing, effective respirator program as required by this section (29 CFR 1910.134), including training, fit testing, maintenance, and use requirements. 

3This APF category includes filtering facepieces, and half masks with elastomeric facepieces. 

4The employer must have evidence provided by the respirator manufacturer that testing of these respirators demonstrates performance at a level of protection of 1,000 or greater to receive an APF of 1,000. This level of performance can best be demonstrated by performing a WPF or SWPF study or equivalent testing. Absent such testing, all other PAPRs and SARs with helmets/hoods are to be treated as loose-fitting facepiece respirators, and receive an APF of 25. 

5These APFs do not apply to respirators used solely for escape. For escape respirators used in association with specific substances covered by 29 CFR 1910 subpart Z, employers must refer to the appropriate substance-specific standards in that subpart. Escape respirators for other IDLH atmospheres are specified by 29 CFR 1910.134 (d)(2)(ii). 

6.1. Respirators for IDLH atmospheres:

6.1.1. Approved respirators:

  • A. Full facepiece pressure demand self-contained breathing apparatus (SCBA) certified by NIOSH for a minimum service life of thirty minutes, or
  • B. Combination full facepiece pressure demand supplied-air respirator (SAR) with auxiliary self-contained air supply.

6.1.2. All oxygen-deficient atmospheres (less than 19.5% 0/2 by volume) shall be considered IDLH.

Exception:   If the responsible Laboratory Personnel can demonstrate that, under all foreseeable conditions, oxygen levels in the work area can be maintained within the ranges specified in between 19.5% and a lower value that corresponds to an altitude-adjusted oxygen partial pressure equivalent to 16% oxygen at sea level than any atmosphere supplying respirator may be used.

6.2. Respirators for non-IDLH atmospheres: 6.2.1. For protection against vapors and gases, Sanford Lab shall provide:

  • A. An atmosphere-supplying respirator, or
  • B. An air-purifying respirator, provided that: i. respirator is equipped with an end-of-service-life indicator (ESLI) certified by NIOSH for the contaminants, or

ii. if there is no ESLI appropriate for conditions of employer’s workplace, the employer implements a change schedule for canisters and cartridges that will ensure that they are changed before the end of their service life and describes in the respirator program the information and data relied upon and basis for the change schedule and reliance on the data.   

6.2.2. For protection against particulates, Sanford Lab shall provide:

A. Atmosphere-supplying respirator; or An air-purifying respirator equipped with high efficiency particulate air (HEPA) filters certified by NIOSH or with filters certified for particulates under 42 CFR Part 84; or

B. An air-purifying respirator equipped with any filter certified for particulates by NIOSH for contaminants consisting primarily of particulates with mass median aerodynamic diameters of at least 2 micrometers.

6.3. Escape Only Respirators:

Escape only respirators are required to be within 25ft proximity of any Laboratory Personnel who enter the underground lab. The two types of escape only respirators available are the MSA W65 rescuer and the Drager Oxy K self rescuer.  Laboratory Personnel are to be trained on the inspection and use of each type of respirator used.  A Drager Oxy K self rescuer must be used as an escape only respirator when oxygen deficient atmospheres (such as proximity to cryogenic equipment) could be present.  The EHS Department will serve as resource for proper inspection,  use, and maintenance of escape only respirators.


Every employee who is being considered for inclusion in the Respiratory Protection Program will participate in a medical evaluation.  A determination will be made initially upon employment, or change into a job classification requiring respiratory protection and every 24 months thereafter. Additional medical evaluations are required under certain circumstances, e.g.:

  • Employee reports medical signs or symptoms related to ability to use respirator;
  • Physician or other licensed health care professional (PLHCP), program administrator, or supervisor recommends reevaluation;
  • Information from the respirator program, including observations made during fit testing and program evaluation, indicates a need; or
  • Change occurs in workplace conditions that may substantially increase the physiological burden on an employee.

The employee will fill out the Medical Questionnaire for Respirator Users which will be reviewed by the PLHCP or undergo an initial medical examination that obtains the same information as the medical
questionnaire.  A follow-up medical examination will be provided for an employee who gives a positive response to any questions 1 through 7 in Section 2, Part A of the Medical Questionnaire for Respirator users or whose initial medical examination demonstrates the need for a follow-up medical examination.

The follow-up medical examination will include any medical tests, consultations or diagnostic procedures that the PLHCP deems necessary to make a final determination.

The medical questionnaire and examinations will be administered confidentially during the employee’s normal working hours or at a time and place convenient to the employee.  The questionnaire will be returned to the PLHCP after it has been completed.  The employee may discuss the questionnaire and examination results with the PLHCP.

The purpose of the questionnaire and the initial and follow-up examinations is to guarantee that the employees are physically and psychologically able to perform their work while wearing respiratory protective equipment.  If the PLHCP denies approval, the employee will not be able to participate in the Respiratory Protection Program.

Copies of the medical evaluation and questionnaire will be kept in the employee’s personnel file in accordance with 29 CFR 1926.33.  Copies of the Request for Medical Clearance for each respirator wearer will be available on file at the Administration Building.

The Medical Questionnaire for Respirator Users form can be found in Appendix A of this program.

The Request for Medical Clearance form can be found in Appendix B of this program.


8.1. Training

Employees, upon assignment to an area requiring respirators, will be instructed by their supervisors relative to their responsibilities in the respiratory program.  They will also be instructed in the need, use, limitations, and care of their respirator.  The EHS Department is available to assist, monitor, and provide resources for this training.

Retraining will be given at least every 12 months after initial training and/or when changes in the workplace or the type of respirator make the previous training obsolete, inadequacies in the employee’s knowledge or use of the respirator indicate that the employee has not retained the requisite understanding or skill, or any other situation arises in which retraining appears necessary to ensure safe respirator use.  Records of the training given to each individual will be kept in the administration office.

8.2. Fit Testing

Employees who use tight fitting respirators will be properly fitted and tested for a face seal prior to use of the respirator in a contaminated area.  Qualitative fit testing will be performed every 12 months.  This will be accomplished by following the fit test procedures outlined in this program (see Appendix C:  Fit Test Procedures).  Quantitative fit testing is the preferred method for fit testing of full face respirators used in the negative pressure mode for protection greater than 10 times the exposure limit but not to exceed 50 times the exposure limit.

Fit testing will be done initially upon employee assignment to an area where respirators are required.  All tight fitting respirators (negative and positive) will be fit tested.  Positive pressure tight fitting respirators will be fit tested in the negative pressure mode.

Additional fit tests will be conducted whenever the employee reports, or the PLHCP, supervisor, or program administrator makes visual observations of changes in the employee’s physical condition that could affect respirator fit.  Such conditions include, but are not limited to, facial scaring, dental changes, cosmetic surgery, or an obvious change in body weight.

If after passing a fit test, the employee subsequently notifies management (e.g., supervisor, program administrator, or PLHCP) that the fit of the respirator is unacceptable, the employee will be given a reasonable opportunity to select a different respirator facepiece and to be retested.

Individual fit testing records (See Appendix F:  Respirator Fit, Training, & Education Form) will be kept for each employee tested at the corporate office until the next fit test is performed.

Fit testing of employees with any hair growth such as stubble beard growth, beard or long sideburns that extends under the face seal or interferes with valve function is prohibited.


9.1. Facepiece seal protection

Facial hair or any other condition that prevents direct contact between the face and the edge of the respirator will not be permitted with tight fitting half or full facepiece (negative or positive pressure) or loose fitting facepieces.  Eyeglasses, goggles, and other personal protective equipment will be worn in a manner that does not interfere with the respirator sealing surface.

Facial hair or any other condition that interferes with the seal of the respirator facepiece to include the function of exhalation or inhalation valves will not be permitted.

All users of tight fitting facepieces will perform a user seal check each time they put on the respirator.  Methods for performing the user seal checks will be covered in Appendix D:  User Seal Check Procedures.

9.2. Continuing respirator effectiveness

Supervisors will maintain ongoing surveillance of employee exposure or stress.  If conditions change such that respirator effectiveness may be affected, the respirator selection will be re-evaluated.

Employees will be allowed to leave the contaminated work area under the following conditions:

  1. To wash face and facepiece as necessary to prevent skin or eye irritation.
  2. Detection of vapor or gas breakthrough, changes in breathing resistance, or facepiece leakage.
  3. To replace the respirator or filter, cartridge, or canister.
  4. Upon malfunction of the respirator.
  5. If severe discomfort in wearing the respirator is detected.
  6. Illness of the respirator wearer, including: sensation of dizziness, nausea, weakness, breathing difficulty, coughing, sneezing, vomiting, fever and chills.

If an employee leaves the work area for any of the above reasons, they will not re-enter until the specific problem has been identified and corrected.

9.3. Voluntary Use

Voluntary use of respirators shall be allowed only under the following conditions: 

  1. Sanford Lab shall provide respiratory protection for employees who ask for it or let employees use their own respiratory protection, if such respirator use will not create a hazard.
  2. Sanford Lab shall provide voluntary respirator users with the information contained in Appendix G:  Voluntary Use of Respirators (1910.134 App D Information for employees using respirators when not required under the standard).
  3. Fit testing is not required for voluntary respirator use.

Voluntary use of filtering facepieces (also known as “dust masks”) is exempt from enrollment in  the respiratory protection program.


Respirators will be properly maintained to retain their original effectiveness by periodic inspection, repair, cleaning and proper storage.

10.1. Inspection

The wearer of a respirator will inspect it daily whenever it is in use, prior to use and during cleaning.  Supervisors will periodically spot check respirators for fit, usage, and condition.  The use of defective respirators will not be permitted.  If a defective respirator is found during inspection, it will be taken out of service and discarded or repaired.

10.2. Repair

During cleaning and maintenance, respirators that do not pass inspection will be replaced or repaired immediately.  Repair of the respirator will be done with parts designed for the respirator in accordance with the manufacturer’s instructions.  No attempt will be made to replace components or make adjustments, modifications or repairs beyond the manufacturer’s recommendations.

10.3. Cleaning

Respirators not discarded after one shift use will be cleaned on a daily basis (or after each use if not used daily) according to the manufacturer’s instructions by the assigned employee or other person designated by the Respiratory Protection Program Administrator.  Facilities and supplies for cleaning these respirators will be made available.  The respirator cleaning procedure is outlined in Appendix E:  Respirator Cleaning Procedures.

10.4. Storage

Respirators not discarded after one shift use, will be stored in a suitable container away from areas of contamination.  The respirators will be stored in a location where they are protected from sunlight, dust, heat, cold, moisture, and damaging chemicals and they will be stored in a manner to prevent deformation of the facepiece, exhalation valve, and/or headstrap.  Whenever feasible, respirators not discarded after one shift use, will be marked and stored in such a manner to assure that they are worn only by the assigned employee.


11.1. Program Administration
The EHS Department has the responsibility for the administration of the respiratory protection program.  The EHS director will appoint a respiratory protection program administrator (RPA).  This individual has the authority to act on any and all matters relating to the operation and administration of the respiratory protection program.  All employees will cooperate to the fullest extent.     This individual is responsible for ensuring that:

  • exposure assessments and monitoring of the respiratory hazards are conducted 
  • worksite-specific procedures for this program are developed 
  • All associated records are maintained
  • yearly program audits are conducted

The following providers are used for the medical evaluation of each employee who will wear a respirator (PLHCP).

#1 Designated Physician or licensed health care professional:

  • Medical Facility: Lead-Deadwood Regional Hospital  
  • Address:  Sherman St., Deadwood South Dakota 
  • Phone Number: 605-722-6101    

#2 Designated Physician or licensed health care professional:

  • Medical Facility: Occupational Health Network  
  • Address:  1161 Deadwood Ave, Rapid City South Dakota 
  • Phone Number: 605-718-2778    

This organization is responsible for determining the content and evaluating the results of all required respirator medical evaluations for this program.

Sanford Lab may elect to employ an outside agency for additional help in contaminant identification and measurement, including technical support, air sampling, and laboratory analysis.  If any additional environmental safety and health plans are written for the project, they will be included as an attachment to this program for the designated project.

11.2. Program Evaluation 
This program will be periodically reviewed and evaluated every 12 months.  The program will be audited by using the procedures outlined in this plan.  The evaluations of the workplace will be carried out to ensure that the current written program is effectively implemented.  They will include regular consultations with employees using respirators to assess their view on program effectiveness and to identify any problems.  Factors to be assessed include:  respirator fit (including the ability to use the respirator without interfering with effective workplace performance), appropriate respirator selection for the hazards to which the employee is exposed, proper respirator use under workplace conditions the employee encounters, and proper respirator maintenance.  These factors are included in the Program Evaluation process.

A written report will be made of each evaluation, summarizing the findings.  For each deficiency identified, corrective action taken will be noted.  Copies of the program evaluation (summary report) will be kept in the Administration Building.


12.1. Standards

  • 29 CFR 1910.134: Respiratory Protection
  • 29 CFR 1926.103: Respiratory Protection

12.2. Appendices

  • Appendix A:  Medical Questionnaire For Respirator Users
  • Appendix B:  Medical Clearance For Respirator Use
  • Appendix C:  Fit Test Procedure
  • Appendix D:  User Seal Check Procedures
  • Appendix E:  Respirator Cleaning Procedures
  • Appendix F:  Respirator Fit Test: Training & Education Form
  • Appendix G:  Voluntary Use of Respirators