Silica Dust & Respiratory Safety (OSHA Table 1)

Grinding concrete, cutting tile and stone, shot blasting and cleaning up the dust all release respirable crystalline silica. OSHA's construction standard, 29 CFR 1926.1153, sets the limits and the controls.^[2] Here is what it means for flooring work.

The numbers

OSHA sets two exposure thresholds for respirable crystalline silica in construction.

• Permissible exposure limit: 50 µg/m³ as an 8-hour time-weighted average.^[2]
• Action level: 25 µg/m³ as an 8-hour time-weighted average.^[2]

Two ways to comply

The standard gives employers two paths to meeting those limits.

1. Follow Table 1. For each listed task, use the listed engineering controls, work practices and respirators exactly as written. Doing so fully means you don't have to measure exposures for that task.^[2]
2. Assess exposures. For tasks not on Table 1, or where you can't follow it fully, measure exposures and keep them under the PEL.^[1][2]

Table 1 entries flooring crews use most

Most flooring crews will find their tools in a handful of Table 1 entries.^[2]

Table 1 has more conditions than fit in a summary, such as maintaining tools per the manufacturer and filter-cleaning requirements. Check the full table before relying on it.

Other requirements

Following Table 1 covers the controls at the tool. The standard also has program-level requirements.^[1][2]

• A written exposure control plan describing the tasks, controls, work practices and access restrictions.
• A competent person who makes frequent and regular inspections of job sites, materials and equipment.
• No dry sweeping or compressed air for cleanup where they could contribute to exposure, unless wet methods or HEPA vacuums aren't feasible.
• Medical exams for workers required to wear a respirator under the standard for 30 or more days a year.

Practical setup

On the job, most of compliance comes down to how well the dust collection is set up and maintained.

• Match the collector to the grinder. Check the grinder manufacturer's recommended airflow and the collector's rating before the job, not after the filter loads up.
• A pre-separator catches most of the heavy dust before it reaches the filter, which keeps airflow up.
• Emptying the collector is one of the dustiest moments on the job. Bag-out collectors keep that dust contained.
• More detail: Dust extraction: matching a HEPA vacuum to your grinder.

Common mistakes

Most silica exposure on flooring jobs comes from gaps in setup or cleanup, not from the main cutting or grinding.

• Undersized vacuum on a handheld grinder. A 7" wheel needs 175 cfm or more under Table 1.^[2]
• Letting filters load up. Airflow drops long before the vacuum looks full, so clean or pulse the filter on a schedule.
• Dry-sweeping between passes. Vacuum with HEPA instead.
• Forgetting the helper. The person bagging dust and cleaning up is exposed too.

Dust collection

These are the collectors and vacuums we carry for grinding and cutting work.

• National DL2000 Dust Collector
• National DL3000 Dust Collector
• National DLS2000 Pre-Separator
• Pulse-Bac 2450 Longopac Bagger HPLM Series Vacuum
• Taylor EDC.400 Extreme Dustmaster HEPA Vacuum
• All dust collectors and vacuums

Check each collector's airflow and filter rating against the Table 1 entry for your tool.

Regulations and references

1. OSHA: Respirable crystalline silica in construction
2. OSHA 29 CFR 1926.1153, full text including Table 1