We recently hosted a free webinar on silica dust to help construction industry professionals understand the requirements and provisions of OSHA’s new rule. The event generated a lot of great discussion about how to identify and mitigate silica dust hazards in construction environments. Below you’ll find an edited version of the Q&A portion, which includes several frequently asked questions about silica dust.
If you missed the live event, you can still watch a recording of it online here:
- [Webcast] Silica Dust: Understanding the Requirements & Provisions for Construction Industry Compliance
Topic 1: Silica dust hazards and compliance
Where can I get a copy of OSHA’s new silica dust rule and the safe harbor table for construction?
All of the information about the guidelines is available on OSHA’s website on the Silica Dust Rule page.
How do I know when silica dust is a hazard for my workers?
The easiest way to identify hazardous activities as defined by OSHA is to consult Table 1 of the standard. Table 1 covers about 80% of the activities. If you have questions about an activity not specifically covered in the standard, you can send a query directly to OSHA.
Topic 2: Collecting and disposing of silica dust
How do you safely collect and dispose of silica dust?
We recommend using an industrial vacuum cleaner with a HEPA filtration system. Nilfisk offers several vacuum variants that meet the requirements. Learn more about them here.
Regardless of what type of vacuum you’re considering, we recommend ensuring it meets these two requirements:
- Sufficient filtration. Specifically, we recommend multi-stage filtration with a HEPA filter to capture the small particles.
- A collection bag. This will help you minimize the amount of material dispersed back into the atmosphere because of handling, such as cleaning or emptying the vacuum.
What is the difference between a HEPA filter and a ULPA filter?
ULPA stands for “ultra-low particulate air.” This type of filter is one step up from a HEPA filter.
- HEPA filters are designed to filter down to 99.97% at 0.3 microns.
- ULPA filters will filter down to to 99.999% at 0.18 microns.
ULPA filters are typically used in cleanroom environments and in the medical and semiconductor industries.
For OSHA’s current silica dust standard, you don’t need a ULPA filter — a HEPA filter is sufficient. However, most of our vacuums have the option to add a ULPA filter if you want one.
Can HEPA vacuums collect wet material?
Yes, and we have quite a few HEPA vacuums that can collect wet material. If you choose another vacuum, be sure you check with the manufacturer. Sometimes you’ll need to add a pre-filter or replace one of the other filters or in order for a vacuum to do wet pick-up.
Topic 3: Industrial vacuums
How do you prevent a vacuum filter from getting clogged?
The best way is to use an automated or a manual filter cleaning system.
Many of our vacuums have a PullClean or InfiniCleanTM system, which automatically purges the filters to keep them from getting clogged. Some of our larger vacuums have a manual filter cleaning system, and the more often the filter is cleaned, the longer its lifespan will be.
Do you have to use the vacuum with a bag?
Some vacuums do work best with a bag, but they’re not required to have a bag. However, all vacuums should be used with multi-stage filtration.
We can put an optional polyliner bag on several of our bigger industrial vacuums, but our main star filter will filter down to 99%, down to 3 microns. Then, a HEPA filter will filter through the main filter, down to 99.97%, down to 0.3 microns.
Keep in mind that the collection bag is there to assist you in collecting the material and also to minimize the amount of residual dust that you might kick into the atmosphere via pluming caused by dumping and emptying the filter and the container.
Once a vacuum bag is full, how do I dispose of it properly?
The actual disposal of the material is up to you. It will depend on the regulations that apply to your jobsite. Remember that silica dust is considered a carcinogen, so all applicable local, state, and federal laws need to be addressed when disposing of that material.
For collecting the material out of the container, we recommend either tying a knot in the bag or sealing it using a wire tag or duct tape.
Is there a limit to the length of hose that will reduce the effectiveness of the vacuum?
Every vacuum manufacturer will have a recommended maximum hose length to minimize the amount of residue left in the hose.
For most Nilfisk industrial vacuums, we recommend that your hose length doesn’t exceed 25 or 30 feet. There are situations where it can be more and situations where it can be less, but this is a general guideline.
Again, check with your vacuum manufacturer. They should have that information readily available.
What kind of power tools can be used with the vacuum cleaners?
That depends. You’ll need to check with the manufacturer of the tool. They will have recommendations regarding equipment and/or set-ups.
Nilfisk has several options that can be adapted for or used with tools from many manufacturers. Because it’s so important for safety, we’ll continue to offer more in the future.
Do you sell a line of adapters that will allow you to fit the shrouds of various manufacturers’ grinders and rotary hammers that are the same diameters as your hoses?
We do have some adapters that come with the Blue Line vacuums. These adapters are designed to fit tools from the majority of the more popular brand name manufacturers. However, you may have to ask your manufacturer for a specific adapter for the tool. For the most part, ours will fit up to the 1.5 inch or 32 mm adapter on most tools.
Are your reps available to train on this new rule and on your equipment on our jobsites?
Our reps can visit your jobsite to do a site assessment and make a vacuum recommendation. They can guide you through the rules, but it’s really up to you to determine how the regulations affect you specifically.