很多国家为了保护工人免受粉尘的危害,都制定了各种粉尘的容许浓度。但在多年的粉尘卫生标准的制订中一直重视粉尘中的游离二氧化硅含量,大多数国家都是以粉尘中游离二氧化硅含量作为制订粉尘容许浓度的依据。并根据粉尘中游离二二氧化硅含量和致肺纤维化程度将粉尘分为有害性粉尘和生物学惰性粉尘。如 In many countries, various concentrations of dust have been established to protect workers from the hazards of dust. However, in the formulation of many years of dust hygiene standards, attention has been paid to the content of free silica in dust. In most countries, the content of free silica in dust is taken as the basis for formulating the allowable concentration of dust. According to the level of free silica in the dust and the degree of pulmonary fibrosis, the dust is divided into harmful dust and bio-inert dust. Such as