Summer dangerous chemical safety moment dare not relax !

Major safety risks of hazardous chemicals in summer

1.The increase in temperature increases the volume and pressure of dangerous chemicals

The expansion coefficient of flammable liquid is generally relatively large, stored in a closed container, the volume is easy to expand after heat, and the vapor pressure increases, so that the internal pressure of the container increases, easy to cause container failure, or even crack. The phenomenon of "drum" and the explosion of glass containers in high temperature season containing flammable liquid are caused by thermal expansion. If the container is open, the liquid expands beyond its capacity and spills, running, bubbling, dripping, or leaking.
In order to prevent this situation, in addition to taking heat prevention and cooling measures, it is necessary to control the filling amount, that is, filling according to the prescribed filling coefficient.

In the case of gases, the coefficient of expansion is even greater. Gas is usually contained in a cylinder. As the temperature increases, the pressure in the cylinder increases. For example, when the oxygen cylinder is 0℃, the pressure in the cylinder is 150kg/cm; When the temperature rises to 54.6℃, the pressure rises to 180 kg/cm2. If the pressure is too high, the cylinder risks exploding.

2.The rising temperature makes the liquid evaporate faster

The evaporation capacity of flammable liquid is not only related to the nature of the liquid itself, but also affected by the surrounding environment, and the temperature is more important to it. The higher the temperature, the faster the evaporation of flammable liquid, the greater the vapor concentration on the liquid surface, the greater the possibility of forming an explosive mixture of gases with the air, and the greater the risk of fire and explosion. The evaporation rate of different liquids varies with temperature, boiling point, specific gravity and pressure. The ease with which a flammable liquid evaporates is expressed by its boiling point. The lower the boiling point, the more evaporative the liquid is. The boiling point of some flammable liquids is very low, for example, at atmospheric pressure, the boiling point of gasoline is 50℃, if the ambient temperature exceeds its boiling point, it is prone to danger.

3. Increasing temperature accelerates oxidative decomposition and spontaneous combustion

Due to the influence of temperature, humidity and other environmental factors, many dangerous chemicals are easy to decompose after heat, release oxygen and even oxygen atoms, make other substances oxidize, and release a lot of heat at the same time. If ventilation is poor, heat accumulation does not disperse, resulting in temperature rise, and will accelerate the rate of oxidation, produce more heat, and promote the temperature to continue to rise, when the temperature reaches the spontaneous combustion point of the substance, the substance will spontaneously ignite. Some low spontaneous combustion point material such as yellow phosphorus (spontaneous combustion point of 30℃), if not properly stored, summer temperature exceeds its spontaneous combustion point, in the air can spontaneous combustion fire.

In order to deal with the high safety risk of dangerous chemicals in high temperature weather, enterprises involved in the risk need to take preventive measures .