RESPIRATORY ORGANS PROTECTION FROM THE AMMONIA ACTION

Abstract

The article deals with the issues of protection of the respiratory organs from the toxic effects of ammonia, based on the research of employees of the Physical-chemical institute for environment and human protection of MES OF Ukraine and NAS of Ukraine. The physicochemical properties of ammonia and its toxicological characteristics are discussed in detail. Emergency hygienic regulations and reference levels of its concentration in the air are given, depending on the severity of possible effects. Activated carbon, the most widely used for equipping gas-absorbing cartridges of respirators and industrial gas masks, does not have the ability to selectively absorb ammonia without treatment with chemically active compounds. To enhance selectivity, activated carbon is infiltrated with d-metal salts and organic polybasic acids. An alternative to granular charcoal sorbents are ion-exchange fibrous materials or impregnated fibrous chemisorbents (IFCS), which have a significantly lower weight and breathing resistance. Impregnation was carried out with solutions of citric acid, and glycerol, sodium chloride, and ethanol were used as modifiers to achieve a uniform distribution of citric acid on the surface of the fibers and increase adhesion to them. The study of the sorption characteristics of IFCS as part of the gas-absorbing cartridge of the «Klen-K1» respirator was carried out with dry and moistened samples under dynamic conditions close to the actual operation of respiratory protection equipment: NH3 concentration in the gas-air mixture 700 mg/m3 (35 TVL), relative humidity φ = 0 ÷ 72%, linear flow rate – 5,1 sm/s. It is shown that the humidity of the gas-air mixture plays a decisive role in the efficiency of ammonia sorption, it activates the protective properties of IFCS. It has been established that gas-absorbing cartridges equipped with the developed samples of IFCS impregnated with a 40.0% solution of citric acid with the addition of 3.3% glycerol and 1.0% sodium chloride provide the normalized requirements for class K1 gas filters (ammonia) with humidity of the inhaled air ≥ 30%. The presence of «free» water provides a more complete «activation» of the specified chemisorbent for this toxicant.