Frequency Asked Questions

A properly selected filtering respirator should allow the user to work efficiently in dusty and strenuous conditions, while at the same time guaranteeing an acceptable price level. The description of each respirator takes into consideration some specific features:

1. Filtering efficiency.This is specified by means of a standard. All manufacturers are obliged to ensure the following levels of efficiency:Table 2
   

   CLASS FILTRATION	MAX CONCENTRATION OF IMPURITIES	EFFICIENCY FILTRATION	TYPE AEROSOL
   P1	4 X NDS	80 %	dust, smoke, mist
   P2	10 X PAC	94 %	dust, smoke, mist
   P3	30 X PAC	99 %	dust, smoke, mist

   *Respirators of the following classes:

   • P1, P2, P3 are tested with the sodium chloride method and oil spray. Wytrzymanie przez półmaski długiego testu oraz spełnienie pozostałych wymagań normy oznacza wysoką jakość produktów. Nowa metoda badań ma również znaczenie dla użytkownika. Podnosi ona bowiem wymagania dla produktów, a co za tym idzie podnosi bezpieczeństwo na stanowiskach pracy.
2. Typical applications:
   • Respirator class P1 is used in agriculture, the food industry, quarries, cement plants, the building industry, soft woodworking (coniferous), in particular for dusty and smoky environments from such substances as: calcium carbonate, graphite, gypsum, chalk, cement, plaster, marble, zinc oxide, plant pollens, cellulose, sulphur, cotton, filings from ferrous metals, coal dust containing less than 10% of free silica.
   • Respirator class P2 is used in the mining industry, the chemical industry, shipyards, the metallurgical industry, hard woodworking (deciduous), in particular for such dust and smoke from: asbestos, quartz, aluminium, copper, barium, titanium, vanadium, chromium, manganese, coal dust containing more than 10% of free silica.
   • Respirator class P3 is used in welding and soldering processes, with high concentrations of extremely hazardous, microscopic breathable dusts, with compounds containing: beryllium, antimony, arsenic, cadmium, cobalt, nickel, platinum, radium, strychnine.
3. Dust-holding capacity:Each respirator is characterised by a given inhalation resistance. With time, resistance begins to increase as a result of dust collected in the cup. From the point of view of the user, those respirators are better which will absorb relatively more dust while their inhalation resistance increases to a lesser extent.
4. Exhalation resistance:This depends on the concentration of carbon dioxide and steam between the respirator cup and the face (the so-called dead space). With each exhaling, another measure of carbon dioxide is taken in, which results in a decreased working efficiency. This effect may be reduced by minimising the dead space and employing exhaust valves which speed up the circulation of gases in space.
5. Adjustment to user’s face:According to the instructions, the proper placing of the respirator on the face is crucial. When putting on a respirator care must be taken with regard to the proper pressure of the nasal plate and the tight sealing of the surface remaining in contact with the face. Insufficient sealing of the respirator’s edge results in increased leakage, and consequently, loss of filtration efficiency. Facial hair in particular causes an insufficient seal.
6. Comfort in use: this depends on the quality of the filtering materials employed, which should not cause skin irritation, as well as on the culture of the technology employed. Other important factors are the packaging, handling convenience and other features that might be perceived by the user.

Procedure algorithm: In order to properly diagnose and prevent possible hazards, we must answer four basic questions:

1. What is the oxygen content in the surrounding environment ?
2. What form does the hazard take ?
3. What substance are we dealing with ?
4. In what concentrations does it occur ?

Ad. 1

If the oxygen content is less than < 17% volume and (or) the concentration of a toxic substance is less than < 1 % of volume and if such harmful substances occur as undetectable carbon monoxide, a human being may become lethally intoxicated. The only effective protection is the so-called “isolation equipment” in the form of a hood, a helmet, or a full mask, under which filtered air is pumped from the external environment.

Ad. 2

The most frequent hazards for the respiratory tract occur in four forms:

• Solid aerosols (dust, smoke)
• Liquid aerosols (sprays)
• Vapours and gases of harmful substances
• Aerosols as well as vapours and gases of harmful substances

Ad. 3

In the first three cases, we may use respirators or masks with replaceable inserts. The choice of a proper absorber depends on the substance being dealt with (Appendix 2 contains a detailed list).
In the fourth case, an additional dust filter should be placed on the air intake side.
In the first two cases, the use of disposable dust respirators is recommended. While equally efficient, they are much lighter, more comfortable to use and cheaper than re-usable equipment.

Ad. 4

All types of absorbers come in three classes, which determine their absorbency capacity. Thus, we must determine the concentration of the substance with which the given absorber may be used: