A Problem You Can’t See—Yet Breathe Every Day
If you run a grinder across a concrete slab for even a single pass, the dust cloud you raise can carry respirable-crystalline silica (RCS) concentrations of 400 µg/m³—eight times higher than OSHA’s 8-hour permissible-exposure limit of 50 µg/m³. Unlike sawdust, these particles measure just 0.1–4 µm. They slip past an N-95 mask, lodge in the alveoli and never leave, driving silicosis, lung cancer, COPD and kidney disease.
Concrete dust is only half the story. Portland-cement fines are strongly alkaline (≈ pH 12) and carry traces of hexavalent chromium; the mix can burn skin and trigger lifelong dermatitis.
With health at stake and OSHA fines that can top $15 000 per violation, picking the right dust extractor is not a luxury purchase—it is job-site life insurance.
What OSHA Actually Requires
| OSHA Rule | What it means on-site |
| PEL | ≤ 50 µg m-³ respirable silica (8 h TWA) |
| Action level | ≥ 25 µg m-³ triggers monitoring |
| Airflow rule | 25 CFM per inch of blade (7″ grinder → 175 CFM) |
| Vac spec | Filter ≥ 99 % + self-cleaning or cyclone |
| Housekeeping | No dry sweeping or blow-off—HEPA vac only |
Meet those numbers and you work all day without air sampling. Miss them, and you buy monitoring, fines and downtime. To see more information on silica dust and OSHA rules, visit OSHA’s silica pages.
Five Specs That Separate Winners from Citations
- Airflow (CFM). Multiply the largest blade or wheel by 25. A 7-inch grinder needs 175 CFM minimum; a 20-inch planetary polisher needs 300 CFM or more.
- True HEPA 14 Filtration. At 99.995 % efficiency @ 0.3 µm, HEPA 14 traps roughly 20 × more fine particles than a shop-vac bag and even edges the 99.97 % of HEPA 13.
- Self-Cleaning Filter. A JetClean® conical cartridge permits you to clean the filter without shutting down the motor, keeping suction within 95 % of its fresh-filter rating all shift.
- Longopac® Continuous Bagging. Twist, tie, cut—30 seconds and you have a sealed, OSHA-friendly dust package with zero skin or lung contact.
True HEPA Means Math, Not Marketing.
| Filter Class | Stated Efficiency @ 0.3 µm | Particles Escaping per 1,000,000 | OSHA Table 1‐Ready? |
| Shop-vac bag / M-Class | 90 – 95 % | 50,000 – 100,000 | ❌ |
| HEPA 13 | 99.97 % | 300 | ✔ (but minimal margin) |
| HEPA 14 (Depureco option) | 99.995 % | 50 | ✔✔ — 6× cleaner than HEPA 13 |
Why you care: The most-penetrating particle size (MPPS) for concrete dust is ~0.18 µm. At that size the gap between “good” and “great” filtration is thousands of particles per litre of air.
Watch the Dust Disappear — Longopac® in 30 Seconds
Twist → Tie → Cut. Hands stay clean, OSHA stays happy.
- Zero contact – no skin burns from alkaline cement fines, no blown-back dust cloud.
- No downtime – swap linings between grinder passes; keep the crew on the trigger.
- Predictable cost – one 72-ft sleeve yields ~30 sealed bags, so you budget disposal to the penny.
Match Your Tool Size to the Right Dust Extractor
| Tool / Grinder Size | OSHA Required CFM | One-Plug Power | Depureco Model | Why it Fits |
| Hand Tools ≤ 5 in | 125+ | 120 V / 15 A | XM20 JC XM35 JC | 120 V · 226CFM JetClean® · Longopac® |
| 7–10″ Grinders | 150–170 + | 120 V / 15 A | XM35 JC | 226 CFM · HEPA 14 · Longopac® |
| 9–10″ Grinders | 170–200 + | 120 V / 15 A | XM35 JC | 226 CFM · HEPA 14 · Longopac® |
| 13–20″ Scarifiers | 270 – 300 | 110 V / 20 A | M100 H14/LP | 336 CFM · HEPA 14 · Longopac® |
Frequently Asked Questions
Is a shop-vac legal for silica dust?
No. It lacks ≥ 99 % filtration and any self-cleaning feature. A clogged filter starves airflow, breaking the 25 CFM-per-inch rule.
How often do I change a Longopac bag?
Roughly every 30–40 pounds of dust. The sleeve twists shut before you cut it—nothing escapes
Will an XM35-JC trip a 15-amp breaker?
Startup current peaks below 14.5 A, so standard 120 V outlets are safe.
Do I still need a respirator?
Yes. OSHA still expects at least an N95—and ideally a P100 half-mask—because no engineering control is perfect.
The Bottom Line
Respirable silica is invisible, incurable and now heavily regulated. The easiest way to stay healthy and citation-free is to size your extractor by the 25 CFM-per-inch rule and insist on three non-negotiables: HEPA 14 filtration, JetClean-style self-cleaning, and Longopac bagging. Depureco’s XM-series and M H14 series for 120 V, give you an OSHA-ready match for every concrete job you’ll face in 2025.
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