Title
Silica Exposure Control Plan for UNC Chapel Hill, North Carolina
Competent Person
Cory Kirkland, Facilities Services Safety Officer
Effective Date
October 1, 2020
Table of Contents
- Introduction
- Task 1
- Description of Task: Using a stationary saw to cut tile, stone, or other silica-containing materials.
- Equipment: Kobalt KB7004 Wet Tile/Stone Saw.
- Task 2: Equipment A
- Description of Task: Using a handheld power saw to cut masonry, concrete, stone or other silica-containing materials.
- Equipment: Dewalt DCS690 9" Cut Off Saw with integrated water delivery system.
- Task 2: Equipment B
- Description of Task: Using a handheld power saw to cut masonry, concrete, stone or other silica-containing material.
- Equipment: STIHL Chop Saw with integrated water delivery system.
- Task 3
- Description of Task: Using handheld drills on silica-containing materials.
- Equipment: Dewalt DWH050 Drilling Dust Extraction System (includes shroud connected to Dewalt DWV010 Heavy-Duty Dust Extractor Vacuum).
- Task 4
- Description of Task: Using handheld grinder for mortar removal (i.e., tuckpointing).
- Equipment: Dewalt DWE402 4-1/2” Heavy-Duty Small Angle Grinder with Dewalt DWE46100 Tuckpoint Shroud connected to Dewalt DWV010 Heavy-Duty Dust Extractor Vacuum.
- Task 5: Equipment A
- Description of Task: Using a handheld grinder (sander) for uses other than mortar removal.
- Equipment: Festool ETS 125 Series Random Orbit Sanders connected to Festool CT 36 E AC Dust Extractor.
- Task 5: Equipment B
- Description of Task: Using a handheld grinder (sander) for uses other than mortar removal.
- Equipment: Festool PLANEX LHS 225 EQ connected to Festool CT 36 E AC Dust Extractor.
- Task 5: Equipment C
- Description of Task: Using a handheld grinder (sander) for uses other than mortar removal.
- Equipment: Festool RAS 115.04 E Sander connected to Festool CT 36 E AC Dust Extractor.
- Task 5: Equipment D
- Description of Task: Using a handheld grinder for uses other than mortar removal.
- Equipment: Dewalt DWE43066 Heavy-Duty Small Angle Trigger Switch Grinder with Dewalt DWE46152 5" (125 mm) Concrete Surface Grinding Shroud connected to Dewalt DWV010 Heavy-Duty Dust Extractor Vacuum.
- Task 6
- Description of Task: Weighing and Mixing ceramic glaze in Room 122 at the Art Lab.
- Equipment: Hand-held mixer.
- Task 7
- Description of Task: Quarterly sand toad cage changes in the Biology Department at Wilson Hall.
- Equipment: Manual.
Introduction
All employers covered by OSHA’s Respirable Crystalline Silica Standards 1910.1053 and 1926.1153 must develop and implement a written exposure control plan. This plan describes tasks where employees may be exposed to silica on campus and the ways to reduce exposures through controls, work practices and housekeeping methods. This plan is a supplement to the campus policy and standard on crystalline silica.
This plan applies to all UNC-Chapel Hill (UNC-CH) Faculty, Staff (includes all full-time, part-time, temporary), and Students working on behalf of the University.
Task 1
Description of Task: Using a stationary saw to cut tile, stone, or other silica-containing materials.
Equipment: Kobalt KB7004 Wet Tile/Stone Saw.
Controls
- When using a stationary masonry saw to cut silica-containing materials on campus, 1926.1153 Table 1 (i) will be fully and properly implemented.
- The Kobalt KB7004 saw is equipped with an integrated water delivery system that continuously feeds water to the blade as required by Table 1.
- When using the saw indoors or in an enclosed area, provide additional exhaust (e.g. fans, portable ventilation systems, etc.) as needed to minimize the accumulation of visible airborne dust.
Work Practices
- Operate and maintain saw in accordance with manufacturer’s instructions to minimize dust emissions:
- Fill water to the minimum level of the reservoir before cutting.
- Check the water level every 1/2 hour during use and refill if needed. Keep the ventilation slots clean to prevent overheating of the motor.
- Use a damp soft cloth to clean the water and dust off the tile saw after use.
- Conduct the following steps prior to and during the work:
- Check that hoses are securely connected and are not cracked or broken.
- Adjust nozzles so that water goes to the blade and wets the cutting area.
- Inspect the saw blade before use to ensure it is in good condition and does not show excessive wear.
- Stop work and adjust controls if there is an increase in visible dust.
Respiratory Protection
- Respiratory protection is not required for work with stationary masonry saws equipped with an integrated water delivery system regardless of task duration.
Housekeeping
- Clean up any slurry produced before it dries using wet methods or with a wet vacuum equipped with a HEPA filter.
- Dispose of collected slurry into a sealed plastic bag and place bag in a general waste dumpster.
- If slurry dries, immediately wet it down and clean it up. Never sweep or use compressed air on dried slurry.
Procedures Used to Restrict Access to Work Areas
- Use barrier tape to restrict pedestrian access to the work area for general safety concerns.
Task 2: Equipment A
Description of Task: Using a handheld power saw to cut masonry, concrete, stone or other silica-containing materials.
Equipment: Dewalt DCS690 9" Cut Off Saw with integrated water delivery system.
Controls
- When using a handheld power saw on campus to cut silica-containing materials, 1926.1153 Table 1 (ii) will be fully and properly implemented.
- The Dewalt DCS690 9" Cut Off Saw is equipped with an integrated water delivery system that continuously feeds water to the blade as required by Table 1.
- When using the saw indoors or in an enclosed area, provide additional exhaust (e.g. fans, portable ventilation systems, etc.) as needed to minimize the accumulation of visible airborne dust.
Work Practices
- Operate and maintain saw in accordance with manufacturer’s instructions to minimize dust emissions.
- Wet cut method is to be used only with a diamond blade.
- The recommended water flow rate should be at least 20 fl. oz. (0.2 gallons) per minute.
- Maximum supplied water pressure should not exceed 60 PSI.
- Follow the maintenance schedule below:
Maintenance Schedule
| Item |
Before use |
Daily/After work |
| Clean machine |
|
X |
| Check intake port |
|
X |
| Check cutting wheel |
X |
|
| Check water intake |
X |
|
- Stop work and adjust controls if there is an increase in visible dust.
Respiratory Protection
- When used outdoors:
- Respiratory protection is not required if the task duration will be four hours or less per shift.
- Use respiratory protection with an Assigned Protection Factor (APF) of 10 if the task duration is more than four hours per shift.
- When used indoors:
- Use respiratory protection with an Assigned Protection Factor (APF) of 10 for any task duration.
- See the UNC Respiratory Protection Program for information on selection, training, and fit testing requirements, in addition to proper use instructions for respirators.
Housekeeping
- Clean up any slurry produced before it dries using wet methods or with a wet vacuum equipped with a HEPA filter.
- Dispose of collected slurry into a sealed plastic bag and place bag in a general waste dumpster If slurry dries, immediately wet it down and clean it up.
Procedures Used to Restrict Access to Work Areas
- Use barrier tape to restrict pedestrian access to the work area for general safety concerns when respirators are not required.
- When respirators are required, use barrier tape to restrict access to only employees who are engaged in the task. All employees engaged in the task must wear respirators.
Task 2: Equipment B
Description of Task: Using a handheld power saw to cut masonry, concrete, stone or other silica-containing material.
Equipment: STIHL Chop Saw with integrated water delivery system.
Controls
- When using a handheld power saw on campus to cut silica-containing materials, 1926.1153 Table 1 (ii) will be fully and properly implemented.
- The STIHL Chop Saw is equipped with an integrated water delivery system that continuously feeds water to the blade as required by Table 1.
- When using the saw indoors or in an enclosed area, provide additional exhaust (e.g. fans, portable ventilation systems, etc.) as needed to minimize the accumulation of visible airborne dust.
Work Practices
- Operate and maintain saw in accordance with manufacturer’s instructions to minimize dust emissions.
- The recommended flow rate should be at least 20 fl. oz. (0.2 gallons) per minute.
- Follow the maintenance schedule below:
Maintenance Schedule
| Item |
Action |
Before starting work |
At the end of work and/or daily |
Whenever tank is refilled |
| Complete Machine |
Visual Inspection |
X |
|
X |
| Clean |
|
X |
|
| Operating Controls |
Check operation |
X |
|
X |
| Cooling air intake slits |
Clean |
|
X |
|
| Water Attachment |
Test, check |
X |
|
|
| Have maintained by a specialist |
|
|
|
| Abrasive Wheel |
Test, check |
X |
|
X |
| Replace |
|
|
|
Maintenance Schedule
| Item |
Action |
If not functioning properly |
If damaged |
As required |
| Complete Machine |
Visual Inspection |
|
|
|
| Clean |
|
|
|
| Operating Controls |
Check operation |
|
|
|
| Cooling air intake slits |
Clean |
|
|
|
| Water Attachment |
Test, check |
X |
|
|
| Have maintained by a specialist |
|
X |
|
| Abrasive Wheel |
Test, check |
|
|
|
| Replace |
|
X |
X |
- Stop work and adjust controls if there is an increase in visible dust.
Respiratory Protection
- When used outdoors:
- Respiratory protection is not required if the task duration will be four hours or less per shift.
- Use respiratory protection with an Assigned Protection Factor (APF) of 10 if the task duration is more than four hours per shift.
- When used indoors:
- Use respiratory protection with an Assigned Protection Factor (APF) of 10 for any task duration.
- See the UNC Respiratory Protection Program for information on selection, training, and fit testing requirements, in addition to proper use instructions for respirators.
Housekeeping
- Clean up any slurry produced before it dries using wet methods or with a wet vacuum equipped with a HEPA filter.
- Dispose of collected slurry into a sealed plastic bag and place bag in a general waste dumpster.
- If slurry dries, immediately wet it down and clean it up.
Procedures Used to Restrict Access to Work Areas
- Use barrier tape to restrict pedestrian access to the work area for general safety concerns when respirators are not required.
- When respirators are required, use barrier tape to restrict access to only employees who are engaged in the task. All employees engaged in the task must wear respirators.
Task 3
Description of Task: Using handheld drills on silica-containing materials.
Equipment: Dewalt DWH050 Drilling Dust Extraction System (includes shroud connected to Dewalt DWV010 Heavy-Duty Dust Extractor Vacuum).
Use
This drilling dust extraction system has been designed for professional drilling applications in concrete and masonry.
Controls
- When using a handheld drill on silica-containing materials, 1926.1153 Table 1 (vii) will be fully and properly implemented.
- Table 1 requires that drills are used with a commercially available shroud or cowling with dust collection system.
- The DWV010 vacuum is equipped with a HEPA filter (99.97% efficiency) which meets the Table 1 requirements.
- When using drill indoors or in an enclosed area, provide additional exhaust (e.g. fans, portable ventilation systems, etc.) as needed to minimize the accumulation of visible airborne dust.
Work Practices
- Check the following prior to/during work:
- The shroud or cowling is intact and installed correctly.
- The vacuum hose is intact and without kinks or bends.
- The vacuum filter is cleaned and changed in accordance with manufacturer’s instructions. Check filter if there is excessive dust emission.
- Dust collection bags are emptied to avoid overfilling.
- Operate and maintain dust extraction system in accordance with manufacturer’s instructions to minimize dust emissions:
- Dewalt DWH050 Drilling Dust Extraction System
- DO NOT turn off the dust extractor vacuum before removing the drilling dust extraction system from the surface.
- Your drilling dust extraction system has been designed to operate over a long period of time with a minimum of maintenance. Continuous satisfactory operation depends on proper tool care and regular cleaning as needed:
- Clean dust extractor adaptor suction
- Clean drilling head
- Dewalt DWV010 Heavy-Duty Dust Extractor Vacuum
- When the motor has a high-pitched sound and air flow stops, empty the canister.
- Filters typically last between six and twelve months, depending on use and care.
- DO NOT continue use if filters are damaged.
- Inspect filters for wear, tears or other damage as needed.
- Replace filters if there is any doubt on the condition of the filters.
- Never use compressed air or a brush to clean filters.
- Clean dirt and dust out of all air vents with dry air at least once a week.
- If suction capacity decreases:
- Remove any blockages in the suction nozzle, suction tube, suction hose or filters.
- Replace the paper or fleece bag.
- Check for proper installation of the filters. Clean or replace the filters if needed.
- Empty canister.
- Stop work and adjust controls if there is an increase in visible dust.
- Attach the dust extraction cleaning nozzle to the HEPA vacuum cleaner to clean drilled holes.
Respiratory Protection
- Respiratory protection is not required for use of drill with dust collection regardless of task duration.
Housekeeping
- Silica containing dust on work surfaces and equipment must be cleaned up using wet methods or HEPA vacuum.
- Dispose of used vacuum bags in a sealed plastic bag and place bag in a general waste dumpster.
Procedures Used to Restrict Access to Work Areas
- Use barrier tape to restrict pedestrian access to the work area for general safety concerns.
Task 4
Description of Task: Using handheld grinder for mortar removal (i.e., tuckpointing).
Equipment: Dewalt DWE402 4-1/2” Heavy-Duty Small Angle Grinder with Dewalt DWE46100 Tuckpoint Shroud connected to Dewalt DWV010 Heavy-Duty Dust Extractor Vacuum.
Use
These heavy-duty small angle grinders have been designed for professional grinding, sanding, wire brush, and cut-off applications at various work sites (i.e., construction sites). The tuckpoint shroud has been designed for professional tuckpoint masonry applications.
Controls
- When performing tuckpointing, Table 1 (xi) will be fully and properly implemented.
- Table 1 requires that handheld grinders (DWE402) used for tuckpointing are:
- Equipped with commercially available shroud or cowling (DWE46100) with dust collection system (DWV010).
- Used with a dust collection system that provides 25 cfm of air flow per inch of wheel diameter. The DWV010 vacuum provides 155 cfm which meets the criteria for the 4.5-inch wheel diameter DWE402 grinder
- Used with a dust collection system with a filter with 99 % efficiency and a filter-cleaning mechanism. The DWV010 vacuum is equipped with a HEPA filter (99.97% efficiency) and mechanism that cleans the filter every 30 seconds.
- When using the grinder indoors or in an enclosed area, provide additional exhaust (e.g. fans, portable ventilation systems, etc.) as needed to minimize the accumulation of visible airborne dust.
Work Practices
- Ensure the following prior to and during work:
- The shroud or cowling is intact, encloses most of the grinding blade and installed correctly.
- The vacuum hose is intact and without kinks or bends.
- The vacuum filter is cleaned and changed in accordance with manufacturer’s instructions. Check filter if there is excessive dust emission.
- Dust collection bags are emptied to avoid overfilling.
- Blade is kept flush against the surface whenever possible.
- The grinder is operated against the direction of blade rotation, whenever practical.
- Operate and maintain dust extraction system in accordance with manufacturer’s instructions to minimize dust emissions:
- DWE402 4-1/2” Heavy-Duty Small Angle Grinder
- Clean dirt and dust out of all air vents at least once a week.
- Dewalt DWE46100 Tuckpoint Shroud
- Clean dirt and dust out of all air vents at least once a week.
- This attachment MUST BE used with a dust extractor system. Keep the edge of the shroud against the work surface to ensure proper dust collection. For the best results, the grinder should be positioned at a 45° angle to the dust port when tuckpointing/cutting.
- Dewalt DWV010 Heavy-Duty Dust Extractor Vacuum
- When the motor has a high-pitched sound and air flow stops, empty the canister.
- Filters typically last between six and twelve months, depending on use and care.
- DO NOT continue use if filters are damaged.
- Inspect filters for wear, tears or other damage as needed.
- Replace filters if there is any doubt on the condition of the filters.
- Never use compressed air or a brush to clean filters
- Clean dirt and dust out of all air vents at least once a week.
- If suction capacity decreases:
- Remove any blockages in the suction nozzle, suction tube, suction hose or filters.
- Replace the paper or fleece bag.
- Check for proper installation of the filters. Clean or replace the filters if needed.
- Empty canister.
- Stop work and adjust controls if there is an increase in visible dust.
Respiratory Protection
- Use respiratory protection with an Assigned Protection Factor (APF) of 10 if the task duration is four hours or less per shift.
- Use respiratory protection with an Assigned Protection Factor (APF) of 25 if the task duration is more than four hours per shift.
- See the UNC Respiratory Protection Program for information on selection, training, and fit testing requirements, in addition to proper use instructions for respirators.
Housekeeping
- Silica containing dust on work surfaces and equipment must be cleaned up using wet methods or HEPA vacuum.
- Dispose of used vacuum bags in a sealed plastic bag and place bag in a general waste dumpster.
Procedures Used to Restrict Access to Work Areas
- Because respirators are required during the work, use barrier tape to restrict access to only employees who are engaged in the task. All employees engaged in the task must wear respirators.
Task 5: Equipment A
Description of Task: Using a handheld grinder (sander) for uses other than mortar removal.
Equipment: Festool ETS 125 Series Random Orbit Sanders connected to Festool CT 36 E AC Dust Extractor.
Use
The ETS sanders are designed for dry sanding and polishing of silica-containing materials such as composite materials, paint/varnish, filler, and similar materials.
Controls
- When using a handheld sander on silica-containing materials, 1926.1153 Table 1 (xii) will be fully and properly implemented.
- Table 1 requires that handheld sanders are:
- Equipped with commercially available shroud with dust collection system (CT 36 dust extractor).
- Used with a dust collection system that provides 25 cfm of air flow per inch of wheel diameter. The CT36 dust extractor provides 137 cfm which meets the criteria for the 5-inch sanding pad.
- Used with a dust collection system with a filter with 99 % efficiency and a filter-cleaning mechanism. The CT36 dust extractor is equipped with a HEPA filter (99.97% efficiency) and an auto-clean mechanism.
- When using the sander indoors or in an enclosed area, provide additional exhaust (e.g. fans, portable ventilation systems, etc.) as needed to minimize the accumulation of visible airborne dust.
- Contact EHS if the material that will be disturbed is painted or is drywall to verify if there are any lead or asbestos concerns. EHS will provide further guidance if lead or asbestos is present.
Work Practices
- Ensure the following prior to and during use:
- The shroud or cowling is intact and installed correctly.
- The vacuum hose is intact and without kinks or bends.
- The vacuum filter is cleaned and changed in accordance with manufacturer’s instructions. Check filter if there is excessive dust emission.
- Dust collection bags are emptied to avoid overfilling.
- Operate and maintain dust extraction system in accordance with manufacturer’s instructions to minimize dust emissions:
- Festool ETS 125 Series Random Orbit Sander
- Replace the pad when it no longer holds sanding disks in place.
- Do not use compressed air to clean the motor housing of the tool, as you could inject foreign objects into the motor through the ventilation openings.
- As a general rule, keep the sander clean of all dust and debris by wet methods or with a HEPA vacuum.
- Examine all moving parts for dust and debris.
- Festool CT 36 E AC Dust Extractor
- Always use the automatic cleaning system in combination with a disposal bag.
- Empty canister, as necessary. The dust extractor stops automatically when the maximum level is reached.
- If suction decreases, clean the main filter by manually starting the autoclean system. Clean filter completely if severely clogged.
- A dust test must be performed at least once a year by the manufacturer or an instructed person. This test may include checks to determine whether the filter is damaged, the machine is sealed properly and the monitoring features are functioning correctly.
- Stop work and adjust controls if there is an increase in visible dust.
Respiratory Protection
- When used outdoors:
- Respiratory protection is not required for any task duration.
- When used indoors:
- Respiratory protection is not required if the task duration is 4 hours or less.
- Use respiratory protection with an Assigned Protection Factor (APF) of 10 if the task duration is greater than 4 hours.
- See the UNC Respiratory Protection Program for information on selection, training, and fit testing requirements, in addition to proper use instructions for respirators.
Housekeeping
- Silica containing dust on work surfaces and equipment must be cleaned up using wet methods or HEPA vacuum.
- Dispose of used vacuum bags in a sealed plastic bag and place bag in a general waste dumpster. Waste containing lead or asbestos must be disposed by submitting an EHS Waste Pickup Request.
Procedures Used to Restrict Access to Work Areas
- When respirators are not required, use barrier tape to restrict pedestrian access to the work area for general safety concerns.
- When respirators are required during the work, use barrier tape to restrict access to only employees who are engaged in the task. All employees engaged in the task must wear respirators.
Task 5: Equipment B
Description of Task: Using a handheld grinder (sander) for uses other than mortar removal.
Equipment: Festool PLANEX LHS 225 EQ connected to Festool CT 36 E AC Dust Extractor.
Use
The PLANEX is designed for sanding silica-containing materials such as primed drywall, plaster, and paint.
Controls
- When using a handheld sander on silica-containing materials on campus, 1926.1153 Table 1 (xii) will be fully and properly implemented.
- Table 1 requires that handheld sanders are:
- Equipped with commercially available shroud with dust collection system (CT 36 dust extractor).
- Used with a dust collection system that provides 25 cfm of air flow per inch of wheel diameter. The CT36 dust extractor provides 137 cfm which meets the criteria for the 5-inch sanding pad.
- Used with a dust collection system with a filter with 99 % efficiency and a filter-cleaning mechanism. The CT36 dust extractor is equipped with a HEPA filter (99.97% efficiency) and an auto-clean mechanism.
- When using the sander indoors or in an enclosed area, provide additional exhaust (e.g. fans, portable ventilation systems, etc.) as needed to minimize the accumulation of visible airborne dust.
- Contact EHS if the material that will be disturbed is painted or is drywall to verify if there are any lead or asbestos concerns. EHS will provide further guidance if lead or asbestos is present.
Work Practices
- Ensure the following prior to and during use:
- The shroud or cowling is intact and installed correctly.
- The vacuum hose is intact and without kinks or bends.
- The vacuum filter is cleaned and changed in accordance with manufacturer’s instructions. Check filter if there is excessive dust emission.
- Dust collection bags are emptied to avoid overfilling.
- Operate and maintain dust extraction system in accordance with manufacturer’s instructions to minimize dust emissions:
- Festool PLANEX LHS 225 EQ
- To ensure constant air circulation, always keep the air vent slits in the motor housing clean and free of blockages.
- Clean the contact slide regularly.
- Replace self-disconnecting special carbon brushes if worn. If they are worn, power is interrupted automatically and the machine comes to a standstill.
- The PLANEZ is equipped with visual warning signals:
- LED flashing slowly: The machine is overheating due to heavy dirt deposits around the air vent slits and the dust filter.
- Clean the air vent slits.
- Remove the dust filter.
- Remove the dirt deposits.
- Insert the dust filter until it audibly engages.
- Festool CT 36 E AC Dust Extractor
- Always use the automatic cleaning system in combination with a disposal bag.
- Empty canister, as necessary. The dust extractor stops automatically when the maximum level is reached.
- If suction decreases, clean the main filter by manually starting the autoclean system. Clean filter completely if severely clogged.
- A dust test must be performed at least once a year by the manufacturer or an instructed person. This test may include checks to determine whether the filter is damaged, the machine is sealed properly and the monitoring features are functioning correctly.
- Stop work and adjust controls if there is an increase in visible dust.
Respiratory Protection
- When used outdoors:
- Respiratory protection is not required for any task duration.
- When used indoors:
- Respiratory protection is not required if the task duration is 4 hours or less.
- Use respiratory protection with an Assigned Protection Factor (APF) of 10 if the task duration is greater than 4 hours.
- See the UNC Respiratory Protection Program for information on selection, training, and fit testing requirements, in addition to proper use instructions for respirators.
Housekeeping
- Silica containing dust on work surfaces and equipment must be cleaned up using wet methods or HEPA vacuum.
- Dispose of used vacuum bags in a sealed plastic bag and place bag in a general waste dumpster. Waste containing lead or asbestos must be disposed by submitting an EHS Waste Pickup Request.
Procedures Used to Restrict Access to Work Areas
- When respirators are not required, use barrier tape to restrict pedestrian access to the work area for general safety concerns.
- When respirators are required during the work, use barrier tape to restrict access to only employees who are engaged in the task. All employees engaged in the task must wear respirators.
Task 5: Equipment C
Description of Task: Using a handheld grinder (sander) for uses other than mortar removal.
Equipment: Festool RAS 115.04 E Sander connected to Festool CT 36 E AC Dust Extractor.
Use
The RAS 115.04 E is designed for stone, composite materials, paints / lacquers, fillers, stoppers and similar silica-containing materials.
Controls
- When using a handheld sander on silica-containing materials on campus, Table 1 (xii) will be fully and properly implemented.
- Table 1 requires that handheld sanders are:
- Equipped with commercially available shroud with dust collection system (CT 36 dust extractor).
- Used with a dust collection system that provides 25 cfm of air flow per inch of wheel diameter. The CT36 dust extractor provides 137 cfm which meets the criteria for the 4.5-inch sanding pad.
- Used with a dust collection system with a filter with 99 % efficiency and a filter-cleaning mechanism. The CT36 dust extractor is equipped with a HEPA filter (99.97% efficiency) and an auto-clean mechanism.
- When using the sander indoors or in an enclosed area, provide additional exhaust (e.g. fans, portable ventilation systems, etc.) as needed to minimize the accumulation of visible airborne dust.
- Contact EHS if the material that will be disturbed is painted or is drywall to verify if there are any lead or asbestos concerns. EHS will provide further guidance if lead or asbestos is present.
Work Practices
- Ensure the following prior to and during use:
- The shroud or cowling is intact and installed correctly.
- The vacuum hose is intact and without kinks or bends.
- The vacuum filter is cleaned and changed in accordance with manufacturer’s instructions. Check filter if there is excessive dust emission.
- Dust collection bags are emptied to avoid overfilling.
- Operate and maintain dust extraction system in accordance with manufacturer’s instructions to minimize dust emissions:
- RAS 115.04 E Sander
- To ensure constant air circulation, always keep the air vent slits in the motor housing clean and free of blockages.
- The tool is fitted with special motor brushes with an automatic cut-out. When the brushes become worn the power supply is shut off automatically and the tool comes to a standstill.
- Festool CT 36 E AC Dust Extractor
- Always use the automatic cleaning system in combination with a disposal bag.
- Empty canister, as necessary. The dust extractor stops automatically when the maximum level is reached.
- If suction decreases, clean the main filter by manually starting the autoclean system. Clean filter completely if severely clogged.
- A dust test must be performed at least once a year by the manufacturer or an instructed person. This test may include checks to determine whether the filter is damaged, the machine is sealed properly and the monitoring features are functioning correctly.
- Stop work and adjust controls if there is an increase in visible dust.
Respiratory Protection
- When used outdoors:
- Respiratory protection is not required for any task duration.
- When used indoors:
- Respiratory protection is not required if the task duration is 4 hours or less.
- Use respiratory protection with an Assigned Protection Factor (APF) of 10 if the task duration is greater than 4 hours.
- See the UNC Respiratory Protection Program for information on selection, training, and fit testing requirements, in addition to proper use instructions for respirators.
Housekeeping
- Silica containing dust on work surfaces and equipment must be cleaned up using wet methods or HEPA vacuum.
- Dispose of used vacuum bags in a sealed plastic bag and place bag in a general waste dumpster. Waste containing lead or asbestos must be disposed by submitting an EHS Waste Pickup Request.
Procedures Used to Restrict Access to Work Areas
- When respirators are not required, use barrier tape to restrict pedestrian access to the work area for general safety concerns.
- When respirators are required during the work, use barrier tape to restrict access to only employees who are engaged in the task. All employees engaged in the task must wear respirators.
Task 5: Equipment D
Description of Task: Using a handheld grinder for uses other than mortar removal.
Equipment: Dewalt DWE43066 Heavy-Duty Small Angle Trigger Switch Grinder with Dewalt DWE46152 5" (125 mm) Concrete Surface Grinding Shroud connected to Dewalt DWV010 Heavy-Duty Dust Extractor Vacuum.
Use
This power tool is intended to function as a grinder, sander, wire brush, polisher or cut-off tool. The concrete surface grinding shroud has been designed for dust removal of the following: grinding, leveling and polishing concrete surfaces.
Controls
- When using a handheld grinder on silica-containing materials on campus, Table 1 (xii) will be fully and properly implemented.
- Table 1 requires that handheld grinders (DWE43066) are:
- Equipped with commercially available shroud or cowling (DWE46152) with dust collection system (DWV010).
- Used with a dust collection system that provides 25 cfm of air flow per inch of wheel diameter. The DWV010 vacuum provides 155 cfm which meets the criteria for the 5-inch wheel diameter DWE402 grinder.
- Used with a dust collection system with a filter with 99 % efficiency and a filter-cleaning mechanism. The DWV010 vacuum is equipped with a HEPA filter (99.97% efficiency) and mechanism that cleans the filter every 30 seconds.
- When using grinder indoors or in an enclosed area, provide additional exhaust (e.g. fans, portable ventilation systems, etc.) as needed to minimize the accumulation of visible airborne dust.
- Contact EHS if the material that will be disturbed is painted to verify if there are any lead concerns. EHS will provide further guidance if lead is present.
Work Practices
- Ensure the following prior to and during use:
- The shroud or cowling is intact and installed correctly.
- The vacuum hose is intact and without kinks or bends.
- The vacuum filter is cleaned and changed in accordance with manufacturer’s instructions. Check filter if there is excessive dust emission.
- Dust collection bags are emptied to avoid overfilling.
- Operate and maintain dust extraction system in accordance with manufacturer’s instructions to minimize dust emissions:
- Dewalt DWE43066 Heavy-Duty Small Angle Trigger Switch Grinder
- Clean dirt and dust out of all air vents at least once a week.
- Dewalt DWE461525" (125 mm) Concrete Surface Grinding Shroud
- Clean dirt and dust out of all air vents at least once a week.
- The shroud must be securely attached to the power tool and positioned for maximum safety, so the least amount of wheel is exposed towards the operator. The shroud is designed to collect dust and help protect the operator from accidental contact with the wheel.
- The surface grinding shroud and dust extractor vacuum will only be effective when used with a diamond surface cup wheel on a flat surface.
- Dewalt DWV010 Heavy-Duty Dust Extractor Vacuum
- When the motor has a high-pitched sound and air flow stops, empty the canister.
- Filters typically last between six and twelve months, depending on use and care.
- DO NOT continue use if filters are damaged.
- Inspect filters for wear, tears or other damage as needed.
- Replace filters if there is any doubt on the condition of the filters.
- Never use compressed air or a brush to clean filters
- Clean dirt and dust out of all air vents at least once a week.
- If suction capacity decreases:
- Remove any blockages in the suction nozzle, suction tube, suction hose or filters.
- Replace the paper or fleece bag.
- Check for proper installation of the filters. Clean or replace the filters if needed.
- Empty canister.
- Stop work and adjust controls if there is an increase in visible dust.
Respiratory Protection
- When used outdoors:
- Respiratory protection is not required for any task duration.
- When used indoors:
- Respiratory protection is not required if the task duration is 4 hours or less.
- Use respiratory protection with an Assigned Protection Factor (APF) of 10 if the task duration is greater than 4 hours.
- See the UNC Respiratory Protection Program for information on selection, training, and fit testing requirements, in addition to proper use instructions for respirators.
Housekeeping
- Silica containing dust on work surfaces and equipment must be cleaned up using wet methods or HEPA vacuum.
- Dispose of used vacuum bags in a sealed plastic bag.
- All surfaces in the work area should be vacuumed and thoroughly cleaned daily for the duration of the sanding project. Vacuum filter bags should be changed frequently.
- Plastic drop cloths and used vacuum bags should be gathered up and disposed of along with any dust chips or other removal debris. They should be placed in sealed plastic bags and disposed of in general waste dumpsters. Waste containing lead must be placed in a sealed container and disposed by submitting an EHS Waste Pickup Request.
Procedures Used to Restrict Access to Work Areas
- When respirators are not required, use barrier tape to restrict pedestrian access to the work area for general safety concerns.
- When respirators are required during the work, use barrier tape to restrict access to only employees who are engaged in the task. All employees engaged in the task must wear respirators.
Task 6
Description of Task: Weighing and Mixing ceramic glaze in Room 122 at the Art Lab.
Equipment: Hand-held mixer.
Controls
- When conducting this task, the exhaust fan must be operating.
Work Practices
- Employees must ensure the exhaust fan is running prior to conducting task.
- Only use mixer with wet ingredients.
Respiratory Protection
- Although monitored exposure was well below occupational exposure limits, EHS recommends continuing to wear a ½ face air purifying respirator with P100 cartridges. EHS has performed limited monitoring during glaze mixing. Different glazes may contain more silica and/or generate more respirable dust.
- All employees engaged in the task must wear respirators.
Housekeeping
- Silica containing dust on work surfaces and equipment must be cleaned up using wet methods or HEPA vacuum. Ceramic glaze dust may contain hazardous materials such as metals. Dispose of used vacuum bags in a sealed plastic bag and submit an EHS Waste Pickup Request.
Procedures Used to Restrict Access to Work Areas
- Keep door closed when weighing and mixing glazes.
- Place sign on door indicating restricted access when conducting the task.
Task 7
Description of Task: Quarterly sand toad cage changes in the Biology Department at Wilson Hall.
Equipment: Manual
Controls
- When conducting this task, the general building ventilation must be operating.
- Conduct sand disposal outdoors.
Work Practices
- Employees must ensure the building ventilation is running prior to conducting task.
- Wet the sand prior to filling cages. Add more water to sand if there is visible dust.
Respiratory Protection
- Respirators are not required for the task.
Housekeeping
- Silica containing dust on work surfaces and equipment must be cleaned up using wet methods or HEPA vacuum. Dispose of used vacuum bags in a sealed plastic bag and place bag in a general waste dumpster.
Procedures Used to Restrict Access to Work Areas
- Keep door closed when weighing and mixing glazes.
Contact Information
Cory Kirkland
Facilities Safety Officer
919-619-9150
UNC Facilities Safety Website
The University of North Carolina at Chapel Hill
Department of Environment, Health and Safety
1120 Estes Drive Ext., CB# 1650
Chapel Hill, North Carolina 27599
919-962-5507
EHS Website