Ключевые слова: background, biochemical, biohazard, biology, black, brown, chemical, color, damage, danger, design, dirty, drawing, element, energy, environmental, garbage, hazardous, healthcare, illustration, image, keep, label, leaking, medicine, nobody, organism, painting, plastic, poisonous, pollution, protection, radiation, red, safety, science, security, sign, stained, substance, symbol, technology, toxic, war, warfare, warning, waste, yellow,