Description
The MSA 81857 is the air-line filter assembly for the MSA Constant Flow Air-Line Respirator accessories. Ships in 1–2 business days; most orders arrive in 3–7 business days. Constant Flow Air-Line Respirator accessories: every part and NIOSH approval on one page.
MSA 81857 specifications
| Item | Manufacturer data |
|---|---|
| MSA part number | 81857 |
| 81857 | MSA Air-Line Filter, complete with one particulate filter and two organic vapor cartridges (MSA Air-Line Filter 81857 instructions) |
| Name | MSA Air-Line Filter, complete with one particulate filter and two organic vapor cartridges |
| Use | This Air-Line Filter is used as a final particulate filter and nuisance odor sorbent for breathing air entering NIOSH - certified Air Line Respirators. Air entering this filter must be CGA Grade D as per Pamphlet G-7.1 ANSI 286.1-1973. If this unit is used with an oil lubricated compressor, high-temperature alarms, Carbon Monoxide Monitors and additional filtering systems may be required per 29 CFR 1910.134. |
| Description | The MSA AIR-LINE FILTER provides high-efficiency filtration of compressed air for breathing purposes...minimum 99% removal of 0.3 micron and larger diameter particulate, including dusts, mists, fumes, smokes and low concentrations of organic vapors. |
| Pressure | Maximum operating pressure 125 psig. |
| Temperature | Maximum operating temperature 250 F |
| Fittings | one-half inch NPT Female both ends. |
| Size | 6" x 7 1/2" high |
| Weight | 3 pounds |
| Flow | Designed for 25 scfm maximum volume at which the initial pressure drop is 1.0 psig for an assembly with two chemical cartridges and a particulate filter. |
| Efficiency | 99% of .3 Micron when tested according to 30 CFR Part 11 Subpart K |
| Uses | Use with constant flow and pressure demand Air-Line respirators. |
| Replacement kit | 484923 Filter Replacement Kit (includes 8 items); Replace filter cartridge and organic vapor cartridges every 1000 hours of use, or sooner if pressure drop increases or odor is detected. |
| MSA description | 81857 MSA Air-Line Filter |
| Fits | constant flow and pressure demand Air-Line respirators |
Source: MSA Air-Line Filter 81857 instructions; MSA Constant Flow Air-Line Respirators and Accessories data sheet 0112-38-MC; MSA Abrasi-Blast Respirators data sheet 0112-37-MC; NIOSH Certified Equipment List (November 2026).
Constant Flow Air-Line Respirator accessories system data
| Item | Manufacturer data |
|---|---|
| Type | SAR (Type C, continuous flow) accessories |
Source: MSA Constant Flow Air-Line Respirators and Accessories data sheet 0112-38-MC; MSA Air-Line Filter 81857 instructions; MSA Abrasi-Blast Respirators data sheet 0112-37-MC; NIOSH Certified Equipment List (November 2026).
NIOSH approvals recorded for the Constant Flow Air-Line Respirator accessories
| Approval | CEL product line |
|---|---|
| TC-19C-0434 | Constant Flow Airline Type C, Continuous Flow, Supplied-Air Respirtor |
| TC-19C-0435 | Constant Flow Airline Type C, Continuous Flow, Supplied-Air Respirator |
| TC-19C-0600 | Constant Flow Airline Respirator, w/G1 Full Facepieces, Continuous Flow, Type C, Supplied-Air Respirator |
| TC-19C-0601 | same, w/G1 Full Facepieces |
| TC-84A-5719 | Model Duo-Flo Tight Fitting, Continuous Flow, Type CE, Combination Supplied Air and Air Purifying Respirator (P100) |
| TC-84A-6821 | Constant Flow Duo Twin Series Full Facepiece Combination Air Purifying and Supplied Air Respirator (P100) |
Source: NIOSH Certified Equipment List (November 2026).
Approved air-supply hose (MSA data sheet)
| Hose | Lengths and part numbers |
|---|---|
| Neoprene Air-Supply Hose, Brass Hose Coupling | 8 ft.: 481071; 15 ft.: 455020; 25 ft.: 455021; 50 ft.: 455022 |
| Neoprene Air-Supply Hose, Stainless Steel Hose Coupling | 8 ft.: 481077; 15 ft.: 481078; 25 ft.: 481079; 50 ft.: 481080 |
| PVC Air-Supply Hose, Brass Hose Coupling | 8 ft.: 481051; 15 ft.: 471511; 25 ft.: 471512; 50 ft.: 4715123 (as printed); 100 ft.: 484225 |
Source: MSA Constant Flow Air-Line Respirators and Accessories data sheet 0112-38-MC.
Assigned protection factor
| Respirator type (OSHA Table 1) | APF |
|---|---|
| Supplied-air respirator, continuous flow, full facepiece | 1000 |
| Supplied-air respirator, continuous flow, helmet/hood (manufacturer-tested to APF 1,000) | 1000 |
Source: OSHA 29 CFR 1910.134 Table 1 (Assigned Protection Factors). The APF applies only when the respirator is used in a program that meets the standard, including fit testing of tight-fitting facepieces (29 CFR 1910.134(f)) and a cartridge change schedule (29 CFR 1910.134(d)(3)(iii)).
Catalog data
| Item | Manufacturer data |
|---|---|
| Style | Airline Filter |
Source: Manufacturer published product data as carried in our catalog.
An in-line filter for airline respirator systems that removes dusts, mists, fumes, smoke and petroleum vapors from compressed air. It has 1/2 inch NPT inlet and outlet ports.
- Removes at least 99% of particulates 0.3 micron and larger
- Filters dusts, mists, fumes, smoke and petroleum vapors
- 1/2 in NPT inlet and outlet
- Inlet pressure up to 125 psig
MSA 81857 questions
What does the MSA 81857 air-line filter do? This Air-Line Filter is used as a final particulate filter and nuisance odor sorbent for breathing air entering NIOSH - certified Air Line Respirators. Air entering this filter must be CGA Grade D as per Pamphlet G-7.1 ANSI 286.1-1973. If this unit is used with an oil lubricated compressor, high-temperature alarms, Carbon Monoxide Monitors and additional filtering systems may be required per 29 CFR 1910.134.
When is the filter replaced? 484923 Filter Replacement Kit (includes 8 items); Replace filter cartridge and organic vapor cartridges every 1000 hours of use, or sooner if pressure drop increases or odor is detected.
Guides: supplied-air respirators and Grade D air · assigned protection factors · all respirators by model and hazard.
