68 the fire, but there was a danger to the health of Lviv citizens since the container was placed near a trolleybus stop. Extinguishing the fire lasted for several hours because magnesium cannot be extinguished with water, and the means that were available did not make it possible to do it quickly. In Crimea, on October, 17, 2009, a fire started at a depo that stored poisonous chemicals ("Otradnoye", Dzhankoy region). The resulting fire burned about 160 tons of poisonous chemicals. The area of the fire was about 600 square meters. The depo had stored magnesium-containing pesticides since 1960s-1970s. According to one explanation, it is the magnesium that caused a spontaneous combustion of pesticides.

The analysis of the problem of extinguishing fires of magnesium and its alloys is carried out. The urgency of studying the problem is confirmed by the fact that during the extinguishing of class D fires there are factors that can complicate the quenching process. Often, these metals actively react with water, which leads to an even greater spread of the fire and even an explosion. Therefore, special fire extinguishers, which have passed the proper test, are more effective in locating the fire and prevent the burning of the powder to form the "tongues" of the flame. In Ukraine, there is no method for testing the effectiveness of fire extinguishants of special purpose for the extinguishing of class D fires. The normative documents have been analyzed, which specify the procedures for testing extinguishing fire-extinguishing special-purpose fire extinguishing class D. Specifically: the methods are described in the international standard ISO 7165: 2017 «Fire fighting – Portable fire extinguishers – Performance and construction» and GOST 53280.5-2009 Fire fighting systems automatic. Extinguishing agents. Both methods have a number of shortcomings that need to be addressed when creating a Ukrainian fire test method for extinguishing fire extinguishing class D, namely: the dimensions of the metal frame made of sheet steel with a side (500 ± 10) mm, height (150 ± 5) mm for testing with magnesium chips are small; Not specified quantity of gasoline necessary for the rise of magnesium; The gas or oxygen torch used to dissolve magnesium does not provide full-value combustion throughout the area, but only creates separate cells of ignition. A draft methodology has been developed that determines the fire-extinguishing efficiency of powdered powders used in Ukraine. The required amount of fuel for burning magnesium and its alloys is determined. It was ascertained that for the firing of magnesium chips it is necessary to use at least 127 grams of gasoline of the mark A 92. Key words: test method, fire extinguishers of special purpose, extinguishing of fires of magnesium alloys

This research outlines the problems of fire extinguishing in tanks, and describes a projected model of an experimental installation for the vertical tank fire simulation. The research also describes a method of extinguishing fires of oil and petroleum products in vertical steel tanks by supplying low expansion foam to the tank base directly into the fuel layer. The time of diesel fuel and gasoline fires extinguishing with the help of general and special purpose fire-fighting foam agents was calculated. Experimental investigations on definition of the fire-extinguishing efficiency of domestically producted fire-fighting foam agents by subsurface fire extinguishing of tanks were carried out.

The article deals with issues of environmental safety during working with polluted technological oil production equipment. According to the results of experimental studies, the efficiency of the complex method (hydrodynamic, cavitation, mechanical) for purifying pump-compressor pipes, polluted with saline deposits containing natural radionuclides, is shown. A block scheme of an environmentally acceptable process of purifying such equipment is proposed.

During the researches, carried out in the article, sodium chloride recommended itself as the best fire-extinguishing substance. In order to give it the properties of a fire extinguishing powder, two more components were added to it, namely ground slag and aerosil. These components were chosen according to their physical and chemical properties. As evidenced by the corresponding quenching parameters, the optimal composition of the fire extinguishing powder was established on the basis of performed experiments and obtained dependences. The properties of the fire extinguishing powder were improved by adding ground slag and aerosil. These additives increase the heat resistance, insulating and anti-caking ability, fluidity and fire-extinguishing efficiency of the powder. The best results were obtained after using  the extinguishing powder of such composition: sodium chloride - 73.5%, ground slag - 25%, aerosil - 1.5%. Experimental-empirical dependence for determination the extinguishing intensity according to the extinguishing parameters and the fire-extinguishing composition was developed.