2. What does LEL mean ?
LEL means Lower Explosive Limit - it is a safety measure of solvent concentration and expressed as a %. In order for an explosion to take place, there must be a minimum concentration of fuel (i.e. solvent fume).
If we refer to 25% LEL, this means it is 25% of the concentration at which the mixture would explode (together with oxygen and a source of ignition). The LEL of Ethanol, for example, is 3.3%vol and therefore 0.8%vol equates to 25%LEL.
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