Silica Table 1 Respirator Lookup (OSHA 1926.1153)
Table 1 is the shortcut that lets you skip exposure assessment, and it is ALL OR NOTHING.
Example
You enter
- Table 1 task xi
- Where the work happens outdoors
- Hours on this task per shift 5
- Table 1 controls fully and properly implemented? yes
- Assigned protection factor of the respirator provided (0 = none) 10
You get
- Respirator provided SHORT of the required APF 25
- Low APF 10
- High APF 25
- APF shortfall 15
- PEL (µg/m³) 50
Checked against published worked examples from: Occupational Safety and Health Administration.
Details, formula, and sources
Scope1926.1153(c)(1) wants the controls, work practices AND respirator fully implemented, so doing part of it drops the job into monitoring against the 50 ug/m3 PEL. The duration column is a CLIFF at four hours, not a ramp: tuckpointing steps from APF 10 to APF 25 at four hours and one minute, which is a half mask becoming a PAPR -- a different purchase, fit test, and training record. And several rows change or vanish indoors, so a walk-behind saw needs nothing outdoors and APF 10 inside, while a drivable saw has no indoor row at all.
Formula or tablelookup: required respiratory protection and minimum assigned protection factor from Table 1, keyed on the task row, whether the work is outdoors or indoors/enclosed, and whether the task runs four hours or less per shift or more than four hours. Where the Table 1 controls are not fully implemented, or the row has no entry for the location, Table 1 does not apply and 1926.1153(d) governs against a 50 ug/m3 8-hour TWA PEL.
Source and editionOSHA 29 CFR 1926.1153 Table 1 and 1926.1153(c)(1) and (d). A US federal regulation in the public domain, quoted directly.
Free access29 CFR is published in full at no cost by OSHA and the eCFR.
What governsEstimate. AHJ and licensed professional govern.
API field namestask, location, hours_per_shift, controls_fully_implemented, apf_provided, required_apf, low_apf, high_apf, apf_shortfall, pel_ug_m3
- Table 1 is all or nothing controls, work practices, and respiratory protection fully and properly implemented29 CFR 1926.1153(c)(1)
- Duration split four hours or less per shift, versus more than four hours29 CFR 1926.1153 Table 1
- Tuckpointing grinders APF 10 at four hours or less, APF 25 above29 CFR 1926.1153 Table 1 (xi)
- Outdoor-only rows fiber-cement saws, drivable saws, and dowel drilling rigs29 CFR 1926.1153 Table 1
- Fallback 50 ug/m3 respirable crystalline silica as an 8-hour TWA29 CFR 1926.1153(d)
- Control methods assumed in place, not reproduced; read the Table 1 rowroughlogic scope limit, stated