Standard No.:	GBZ/T 192.4-2007
Chinese Name:	工作场所空气中粉尘测定 第4部分:游离二氧化硅含量
English Name:	Determination of dust in the air of workplace-Part 4:Content of free silica in dust
Professional Classification:	C52 Labor sanitation
Professional Classification:	GB National Standard
ICS Classification:	13.100
Issued by:
Issued on:	2007-06-18
Implemented on:	2007-12-30
Status:	VALID
Replace:	GB5748-1985
Language:	English
File Format:	PDF
Word Count:	4000 words
Price(USD):	120 (USD)
Delivery:	via email in 1-3 business day

1 Scope

This part specifies the method to determine the content of free silica in dust of workplace.
This part is applicable to the determination of the content of free silica in dust of workplace.

2 Normative References

The following normative documents contain provisions which, through reference in this standard, constitute provisions of this standard. For dated references, subsequent amendments (excluding corrections) to, or revisions of, any of these publications do not apply. However, all parties coming to an agreement according to this standard are encouraged to study whether the latest editions of these documents are applicable. For undated references, the latest edition of the normative documents referred to applies.
GBZ 159 "Specifications of Air Sampling for Hazardous Substances Monitoring in the Workplace"
GBZ/T 192.1 GBZ/T 192.1 "Determination of Dust in the Air of Workplace - Part 1: Total Dust Concentration"
GBZ/T 192.2 "Determination of Dust in the Air of Workplace - Part 2: Respirable Dust Concentration"

3 Pyrophosphoric Acid Method

3.1 Principle