SU1697002A1 - Method for determining the maximum permissible saturation of combustible materials - Google Patents

Abstract

The method relates to medicine, to the field of toxicological and hygienic investigations. The goal is to accelerate the method. The method consists in placing laboratory animals in a heat chamber, burning the material under examination in a heat chamber by measuring the rectal temperature of animals before and after burning the material and determining the maximum permissible saturation with a significant increase in rectal temperature. 1 tab.

Description

The invention relates to medicine, to the field of toxicological and hygienic studies of non-metallic materials used in shipbuilding, civil aviation, and other branches of the national economy in the design of fireproof premises.

The purpose of the invention is the acceleration of the method.

The method is carried out as follows.

They take 5-7 batches of combustible material in the range of 0.01-1.0 kg / m, one of which, for example 1 kg, is placed in a heat chamber with a volume of 1 m. In this chamber, at a distance of 25–50 cm from the sample being burnt, individual cells with fixed animals with an electrothermometer fixed in the rectum are located. It is advisable not to feed the animals before the experiment, in order to prevent the temperature sensor from being pushed out by the fecal mass. The contacts from the electric sensors are led out of the chamber through thermal connectors to be connected to the recording and measuring equipment. Wire temperature measurement of animals, take into account the range of physiologically

allowable temperature fluctuations, which for the most frequently used in experiments of this genus of rats are 39 ± 0.5 ° C, for guinea pigs 38.5 ± 1 ° C.

A sample of non-metallic material is ignited from a radiation heating panel, for example, on the basis of halogen lamps KG-220-1000, providing heating of a sample of 170x170 mm in size to 800-850 ° C. Heat exposure 30 min. From the maximum weight of a sample of a material whose combustion products do not yet cause a statistically significant increase in the temperature of laboratory animals, the maximum permissible saturation of the material is calculated as the ratio of the maximum permissible mass of material to the volume of the heat chamber.

Example. The maximum allowable saturation of combustible envelope paper material was determined. Permissible saturation, determined according to the method of the prototype, was 0.10 kg / m3. The tests were carried out in an EU-235 heat chamber with a volume of 1 m on 10 laboratory animals - white male rats, which were placed in indie

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visual exchange cells. Measurement of rectal temperature was carried out using an TPEV-1 electrothermometer, adapted to work with rats. Significant changes in rectal temperature in animals were observed at a saturation of 0.08 kg / m3, while the average temperature was 39 ± 1.0 ° C, and at saturation of 0.07 kg / m3, the temperature was in the range of the physiological norm.

The results are shown in the table.

Thus, the maximum permissible saturation of the proposed method is 0.07 kg / m3, which is 1.5 times less than that of the prototype method.

The method allows determining PDN in 30 min instead of 13-14 days.

Claims (1)

Invention Formula The method for determining the maximum permissible saturation (PDN) of combustible material by placing laboratory animals in a heat chamber, burning the material in the thermocamera, characterized in that, to accelerate the method, rectal temperature is measured in animals before and after burning the material and with a significant increase in rectal temperature set the value of PDN