NBC-77 SOF® 40mm NATO Gas Mask Filter

CBRN / TIC / Reactor-Rated Filter with 20-Year Shelf Life

The NBC-77 SOF® is a professional-grade 40mm NATO (Rd 40 × 1/7”) CBRN filter engineered to provide comprehensive respiratory protection against all known chemical warfare agents, toxic industrial chemicals, biological threats, radioactive particulates, and radioactive iodine compounds. Designed for long-term readiness and operational durability, it combines CBRN, TIC, and reactor-rated filtration into a single cartridge.

With a 20-year factory-sealed shelf life, the NBC-77 SOF® significantly reduces lifecycle replacement costs compared to standard 5–7 year filters, making it an ideal choice for preparedness, professional response, and long-term storage. Its rugged hard-shell housing protects the filtration media from impact and environmental damage while maintaining compatibility with all standard 40mm NATO-threaded respirators and PAPRs.

This filter is certified under EN 14387:2004 + A1:2008 and carries the A2B2E2K2HgSXP3 D R REACTOR classification, placing it among the most broadly protective consumer-accessible filters available.

Key Capabilities & Design Features

20-Year Shelf Life (Factory Sealed)
Designed for long-term storage with minimal degradation, reducing replacement cycles and cost of ownership.
NATO-Standard 40mm Thread (Rd 40 × 1/7”)
Compatible with the majority of modern military, law-enforcement, and civilian full-face respirators and PAPRs.
Comprehensive CBRN + TIC + Reactor Protection
Filters chemical warfare agents, industrial gases, riot control agents, particulates, and radioactive iodine (including methyl iodide).
Rugged Impact-Resistant Housing
Hard-plastic shell protects filtration media during transport, storage, and operational use.
Used by Military and CBRN Professionals Worldwide
Proven design trusted by special operations, civil defense, and preparedness professionals.
Multiple Color Options
Available in Black, Ranger Green, and Sandstone (color does not affect performance).

Filter Classification (EN 14387)

A2B2E2K2HgSXP3 D R REACTOR

This classification indicates protection against:

Organic gases and vapors (A2)
Inorganic gases and vapors (B2)
Acid gases and vapors (E2)
Ammonia and amines (K2)
Mercury vapors (Hg)
Chemical warfare agents (SX)
High-efficiency particulates (P3)
Radioactive iodine / reactor-grade filtration (REACTOR)
Dust clogging tested (D)
Reusable (R)

Complete Technical Data — NBC-77 SOF® Filter

Physical Characteristics & Breathing Resistance

Parameter	Specification
Diameter	110 mm
Height	85 mm
Weight	335 g ±5%
Storage Time	20 years (factory sealed)

Breathing Resistance (EN 14387 + A1)

Flow Rate	Requirement	NBC-77 SOF
30 L/min	< 140 Pa	260 Pa
95 L/min	< 600 Pa	980 Pa

Particle Filtration Efficiency

Test Medium	EN Requirement	NBC-77 SOF Performance
Sodium Chloride (NaCl)	99.95%	>99.999%
Paraffin Oil	99.95%	>99.999%

Breakthrough Time & Dynamic Adsorption Capacity

(Tested per EN 14387 at 70% RH, 30 L/min)

Filter Class	Test Gas	Concentration (ppm)	EN Min (min)	NBC-77 SOF (min)	DAC (g)
A2	Cyclohexane	5000	35	39	20.475
B2	Chlorine	5000	20	45	20.250
B2	Hydrogen Sulphide	5000	40	>80	>17.400
B2	Hydrogen Cyanide	5000	25	50	8.400
E2	Sulphur Dioxide	5000	20	25	9.975
K2	Ammonia	5000	40	50	5.250
Hg	Mercury Vapor	13 mg/m³	100 hrs	>170 hrs	>3.900
SX	Cyanogen Chloride	2500	20	25	4.710
SX	Chloropicrin	5000	20	44	44.286
SX	Phosgene	5000	20	>77	>47.058
REACTOR	Methyliodide¹³¹	—	2 hrs	>2 hrs	—

Full Application Range

When used with a compatible respirator or PAPR, the NBC-77 SOF® provides protection against:

Chemical warfare agents (nerve, blister, choking, blood agents)
Riot control agents (CS, CN, CR, OC)
Radioactive particles and radioactive iodine compounds
Toxic industrial chemicals (TICs) including acids, solvents, ammonia, chlorine, mercury vapors
Biological aerosols (bacteria, viruses, toxins, fungi)
Smoke, dust, and combustion byproducts
Agricultural chemicals and pesticides
Industrial solvents such as benzene, toluene, vinyl chloride
Arsenic-based compounds (Clark I & II, Adamsite)
Mustard agents (H, HD, HN variants, Lewisite, CX)
G-series and V-series nerve agents

Storage & Handling Requirements

Store unopened filters between -5 °C to +30 °C, RH <80%
Sealed filters tolerate -30 °C to +50 °C, RH <95%
Do not clean, regenerate, or expose filters to water or compressed air
Dispose of used filters according to local hazardous-waste regulations

Important Notes

⚠️ Filters are sold individually
⚠️ Gas mask not included
⚠️ Color may vary due to availability (Black, Ranger Green, Sandstone)
⚠️ Use only in environments with ≥19.5% oxygen

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NBC-77 SOF® 40mm NATO Gas Mask Filter (CBRN)