Type K and K P Filters for Face Masks: Complete Guide to Respiratory Protection

Introduction

Type K and K P filters are essential Personal Protective Equipment (PPE) designed to provide effective respiratory protection in environments where ammonia and its derivatives, as well as other potentially harmful alkaline gases and vapors, are present.

When combined with respiratory protective equipment (RPE), such as face masks, they ensure reliable protection, and play a crucial role in workplace safety across industrial and laboratory settings where volatile chemicals are handled..

This guide explains how type K and K P filters for respiratory masks work, which substances they neutralize — with a focus onammonia (NH₃) -, the main areas of application and the standards that regulate their safe and compliant use.

 

What Are Type K and K P Filters

Type K filters (green) and type K P filters (green and white) belong to the category of respiratory protective filters used with half masks or full-face masks.
They are widely adopted in the industrial and chemical laboratory sectors.

1. Type K filters → designed to protect against ammonia (NH₃) and its organic and inorganic derivatives, as well as other other potentially harmful alkaline gases and vapors, are present.
   Thanks to their specific adsorbent materials these filters capture and neutralize harmful or irritating substances, ensuring a high level of respiratory safety even in areas with high concentrations of contaminants. 
2. Type K P filters → are combined filters that offer dual protection against alkaline gases and vapors and solid and liquid particles..
   They provide complete defense not only against ammonia and chemical vapors, but also against dust, mist, fumes, and aerosols according to efficiency levels P1, P2, and P3 (with P3 being the highest filtration performance).

Like other respiratory filters, K and K P filters are available in three capacity classes (1, 2, and 3): the higher the number, the greater the durability and filtration efficiency.

Discover Milla filters for respiratory protection. Click here. 

Toxic Substances Requiring Type K and K P Filters

Type K filters are recommended for environments containing alkaline gases and toxic chemicals such as:

1. Ethyleneimine → A highly reactive, toxic organic compound used in resin and plasticizer production. It is irritating to the skin, eyes, and respiratory tract and may be carcinogenic.
2. Hydrazine → A colorless liquid with an ammonia-like odor, used as a reducing agent and rocket propellant. Extremely toxic and corrosive, it can damage the liver, kidneys, and nervous system
3. Methylamine → A colorless gas with a strong ammoniacal odor, used in the synthesis of pesticides, pharmaceuticals, and solvents. Causes acute irritation of the mucous membranes and respiratory distress.
4. Triethylamine → A volatile colorless liquid with a pungent odor, used as a catalyst and chemical intermediate. Irritates eyes, throat, and airways and is highly flammable.

 

Type K P filters are recommended in the presence of:

1. 2-Aminopyridine → A crystalline solid used as an intermediate in the synthesis of pharmaceuticals and pesticides. Toxic if inhaled or ingested, may cause irritation and neurological effects.
   
2. Ammonia (NH₃) → A colorless gas with a sharp, penetrating odor, widely used in fertilizers and industrial cleaners. Highly irritating to eyes, skin, and respiratory passages, and hazardous at high concentrations.
3. Ethylamine → A colorless gas or volatile liquid with an ammonia-like odor, used in the manufacture of dyes, pharmaceuticals, and pesticides. Causes irritation to eyes and airways and is easily flammable.

 

Focus: Ammonia (NH₃) 

Anammonia (NH₃) is one of the most common and hazardous contaminants found in industrial environments.

It is a colorless gas with a sharp, penetrating odor, highly soluble in water, and is widely used in the production of fertilizers, detergents, refrigerants and chemical synthesis processes. At high concentrations, it causes severe irritation to the respiratory tract, eyes, and skin, with possible corrosive effects and risk of pulmonary edema. 

For this reason, in all workplaces where ammonia vapors may be present, the use of type K and K P filters is essential.These filters are specifically designed to neutralize alkaline gases and vapors providing effective respiratory protection.

Discover Milla filters for respiratory protection. Click here. 

Industries Where Type K and K P Filters Are Essential

The use of K and K P filters is crucial in all workplaces where ammonia or its derivatives are used or can be released as gases or vapors.

They are fundamental in:

1. Chemical and pharmaceutical industries, where ammonia is used as a reagent or synthesis intermediate.
2. Fertilizer manufacturing plants, with high ammonia concentrations in production and storage processes.
3. Industrial refrigeration systems, which use ammonia as a refrigerant.
4. Wastewater treatment plants and chemical research laboratories, where exposure to vapors is frequent.
   
5. Industrial cleaning and sanitation sectors, where alkaline vapors from ammonia-based solutions can develop.

In all these settings, using RPE (Respiratory Protective Equipment) with type K and K P filters is essential to ensure occupational safety in compliance with international regulations.

 

Main Standards and Markings 

Type K and K P filters fall under Category Personal Protective Equipment (PPE) III for respiratory protection and are governed by European and international standards ensuring workplace safety. 

The main reference standards are:

1. EN 14387 - European standard defining requirements and performance for gas and vapor filters, including amines and alkaline gases.
   
2. EN 143 - Specifies performance requirements for particle filters (P1, P2, P3), applicable to combined K P filters.
   
3. Regulation (EU) 2016/425 - General provisions for PPE, including marking, classification, and conformity assessment requirements.
   
4. ISO 16975-3 - International guidelines for the selection, use, and maintenance of respiratory filters.
   

Compliance with these standards ensures that type K and K P filters provide certified and effective protection against ammonia and its derivatives in different workplace environments, minimizing occupational exposure risks.

 

Conclusions

Type K and K P filters are essential components of respiratory protection equipment (RPE) in workplaces where ammonia and alkaline vapors are present, even when combined with particulates or aerosols.

Discover our full range of type K and K P filters with universal RD40 EN 148-1 connection, compatible with leading respiratory protection masks, ensuring certified, safe, and high-performance protection in any industrial or laboratory environment:

For more information, contact us for a personalized consultation.