ES&H Manual



6683 Appendix T1

Silica Work Requirements



Jefferson Lab has determined that working with silica carries an unmitigated Risk Code ≥2. At a minimum all tasks involving silica are discussed with the supervisor prior to commencement. An Operational Safety Procedure (OSP) is written for any work considered to be Risk Code >2 in accordance with ES&H Manual Chapter 3210 Work Planning, Control, and Authorization Process.


1.0             Purpose


This appendix provides Jefferson Lab’s minimum requirements when working with silica, including work planning, work activities, and clean-up.


2.0             Scope


This procedure defines mitigation measures for activities involving silica over and above those required by standard protecting measures to reduce respirable silica below occupational exposure limits.


Operations, not listed below, that cause silica particles to become airborne are considered to have a Risk Code >2 and require a Work Control Document. These activities include dry sweeping, scraping, or using compressed air. Contact Industrial Hygiene for appropriate mitigation requirements for these activities.


Depending on the complexity of the activity (i.e. indoors, confined space), Industrial Hygiene may require "hold points" to verify control adequacy (e.g. engineered, Personal Protective Equipment (PPE)). Involve Jefferson Lab Industrial Hygiene in work planning activities.  


The process steps for this procedure coordinate with ES&H Manual Chapter 6683 Silica Safety Program.


3.0             Responsibilities

NOTE:           Management authority may be delegated to a task qualified Jefferson Lab employee at the discretion of the responsible manager.


3.1              Trained Worker

·         Complete and maintain appropriate training:

o   SAF138 Silica Dust Hazards in Construction

o   Medical monitoring, as required

·         Perform work activities within hazard controls.

·         If work conditions change or the mitigations do not appear to be effective (i.e. visible dust), request a hazard evaluation of work activities from Industrial Hygiene

3.2              Supervisor/Subcontracting Officer’s Technical Representative (SOTR)/Sponsor:

·         Provide a complete Work Plan in accordance with process steps.

·         Assign only Trained Workers to silica work.


3.2.1        SOTR also:

·         Inform subcontractors that their Activity Hazard Analysis (AHA or THA) must include the planned technique(s) to mitigate silica exposure and the program used to train workers.

o       Program must comply with 29 CFR 1910 or 1926 requirements as applicable to the task being performed.

·         If provided, submit subcontractor’s silica AHA to Jefferson Lab’s Silica Subject Matter Expert (see ES&H Manual Chapter 2410 Appendix T1 Hazard Issues List – Silica) for approval prior to commencement of work. 


3.3              Industrial Hygiene

·         Perform silica work/area hazard evaluation as appropriate.


4.0             Process Steps


The following tables provide examples of typical activities and materials associated with work at Jefferson Lab. Controls for the activities below are expected to reduce potential exposure below the OSHA action limit for silica. The list was developed using objective data and/or previous sampling data; it is not all-inclusive. Evaluate all tasks prior to commencement of work for potential silica generation. If job is not on this list, contact IH.


Type of Work


General Location

Required Controls*


Grout/Mortar Mixing

≤5 sq. ft. / ≤7 bags



Keep employees upwind of dust when outdoors.

Grout/Mortar Mixing

˃5 sq. ft. / >7 bags


A, C, D





Shoveling Sand




Keep employee upwind of dust when outdoors




Hole Drilling <  1/4 in diameter

<4 holes


Use vacuum for housekeeping (no sweeping)

Hole Drilling >  1/4 in diameter

>4 holes


A or B

Use vacuum for housekeeping (no sweeping)

Hole Drilling > 1/4 in diameter



A or B

B only applies to horizontal surfaces




Saw Cutting - Chop Saw



B, D


Saw Cutting - Hand Held Saw

<1 linear ft.


B, D


Saw Cutting - Hand Held Saw

>1 linear ft.


B,C, D


Saw Cutting - Walk Behind Saw Type Equipment



B, D







Surface Finish



A or B, C, D


Joint Compound Sanding

>1 linear ft.


A, C, D

Some new joint compounds are silica free


Tuck Pointing/Grout Repair - Hand tools



B, D

Tuck Pointing/Grout Repair - Power Tools



A, B, C, D


Jack Hammering



B, D


Construction Type Equipment Operators (Enclosed Cab)

<4 continuous hours


B, C

Sprayer must wear respirator

Construction type Equipment Operators (Enclosed Cab)

>4 continuous hours


B, C

Sprayer and operator must wear respirator


A = Local exhaust ventilation on tool or Point of Operation exhaust

B = Water to eliminate visible dust

C = HEPA filter respirator

D = First aid flush of eye contamination

Guidance by Jefferson Lab Industrial Hygiene, November 2014


4.1              Work Planning


The following process steps are completed by the Supervisor.


Step 1:            Task Hazard Analysis (THA) (see ES&H Manual Chapter 3210 Appendix T2 Task Hazard Analysis Worksheet) include:

·         Engineering Controls – Such as water applied at point of generation, local exhaust ventilation with HEPA filtration.  Contact Industrial Hygiene for other approved methods.

·         Training Requirements – SAF138 Silica Dust Hazards in Construction and medical monitoring.

·         Personal Protective Equipment (PPE) – Air Purifying Respirators or equivalent (see ES&H Manual Chapter 6630 Appendix T2 Respirator Use and Approval Requirements)


Step 2:            Request a hazard evaluation from Industrial Hygiene to address additional concerns.


Step 3:            Assign only Trained Workers to the work. Ensure they are appropriately trained, understand the hazards, and implement appropriate hazard mitigation(s) prior to work.


Step 4:            If the area where the task is performed will or could potentially exceed the PEL/TLV, the area must be posted as a regulated area with the sign shown in Figure 1:

Figure 1: required posting for regulated areas

4.2              Work Activities


Only Trained Workers may perform the following process steps.


Step 1:            Abide by the work plan 

·         Follow all safety precautions as outlined within the work plan.

·         If work conditions change or the mitigations do not appear to be effective (i.e. visible dust), request a hazard evaluation of work activities from Industrial Hygiene.


4.3              Clean-up


NEVER dry sweep, dry brush, or use compressed air to clean-up. 


Step 1:            Vacuum

·         Use a HEPA vacuum – If one is not available, you may obtain one from Industrial Hygiene. 

·         Clean the exterior surface of the vacuum prior to returning to owner.

·         Contact IH when the vacuum is full.   


NOTE: Only Radiation Control Department HEPA Vacuums with current performance testing validations are authorized for use within areas containing radioactive material (e.g.: experimental halls and beam enclosures). All HEPA vacuums and the components, used within these areas, must be surveyed prior to removal and may NOT be disposed of in ordinary trash.


HEPA vacuums used for silica in non-radioactive material areas need to be coordinated through Industrial Hygiene


All Jefferson Lab HEPA vacuums are required to be inspected annually. See Industrial Hygiene for more information regarding these types of inspections.


Step 2:            Surface Wipe Down

·         Use wet cloths or rags to wipe up residual material. 

·         Immediately dispose of used cloths or rags in ordinary trash.



5.0             Revision Summary


Revision 1.1 – 04/24/18 – Removed outdated TLV reference per CATS#STR-2017-12-01-03

Revision 1.0 – 02/24/17 – Updated TPOC from D.Owen to J.Williams; updated to comply with new OSHA standard re: CATS Issue #PD-2016-01-01

Revision 0.3 – 01/07/16 – Updated Scope to include Industrial Hygiene for guidance in work planning activities

Revision 0.2 – 03/17/15 – Periodic Review; replaced Silica Table under 4.0 Process Steps per Technical POC

Revision 0.1 – 06/28/13 – Added responsibility to request hazard evaluation of work to 3.1 Trained Worker and added conditional step to 4.2 Work Activities per M.Logue

Revision 0.0 – 06/08/12 – Initial content











ES&H Division

Jennifer Williams





This document is controlled as an on-line file.  It may be printed but the print copy is not a controlled document.  It is the user’s responsibility to ensure that the document is the same revision as the current on line file.  This copy was printed on 4/26/2018.