Ключевые слова: alert, alertness, attention, authorised access, beware, black, business, care, careful, caution, communication, compulsory, control, controlled, crossbones, danger, dangerous, design, enforced, essential, fumes, gas, graphic, hazard, hazardous, health, health safety, illustration, important, industry, information, information sign, instruction, isolated, mandatory, material, necessary, no people, obligatory, order, order sign, peril, persons, poisonous, regulations, required, requirement, risk, safe, safety, sign, signs, skull, skull and crossbones, substance, symbol, symbols, text, threat, toxic, toxic yellow warning sign, triangle, vigilance, warn, warning, warning sign, warning symbol, white, work, workers, working, workplace, yellow,