1 Scope
This standard specifies terms and definitions, calculation method for highness and classification of work at heights.
This standard is applicable to all kinds of work at heights.
2 Normative References
The following documents contain provisions which, through reference in this text, constitute provisions of this standard. For dated references, subsequent amendments to (excluding amending error in the text), 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 edition of these documents is applicable. For undated references, the latest edition of the normative document is applicable to this standard.
GB 3869-1997 "Classification on Intensity of Physical Work"
GB 4200-2008 "Classified Standard of Working in the Hot Environment"
3 Terms and Definitions
For the purposes of this standard, the following terms and definitions apply.
3.1 Work at heights
Work carried out in high places 2m or more above the datum plane for highness of falling (3.2) and may fall.
3.2 Datum plane for highness of falling
Horizontal plane of the lowest place in possible falling bounds (3.3).
3.3 Possible falling bounds
Cylindrical space lined out with the working position as its center and the possible falling bounds (3.4) as its radius, and it is vertical to the horizontal plane.
3.4 Radius of possible falling bounds
R
A horizontal distance from the working position specified to determine the possible falling bounds (3.3).
Note: Radius of possible falling bounds is expressed with meter; its size depends on the basic highness (3.5) relating to the landform, terrain or building distribution etc of the working field. The specific regulation is made based on statistical analysis of numerous high fall accident cases.
3.5 Basic highness
hb
Height difference of the lowest place in cylindrical space, which is lined out vertical to horizontal plane with working position as its center and a radius of 6m, to the working position.
Note: Basic highness is expressed with meter.
3.6 Highness of work [at heights]
hw
In working area, the maximum value in vertical distance from each working position to their corresponding datum plane for highness of falling (3.2).
Note: The highness of work at high place is expressed with meter; the calculation method is detailed in Appendix A.
4 Classification of Work at Heights
4.1 The highness of work at heights is classified into four sections, including 2m~5m, above 5m and below 15m, above 15m to 30m and above 30m.
4.2 Objective risk factors leading to falling directly are classified into 11 categories:
a) Gust with its wind force above five grade (wind speed 8.0m/s);
b) Hot environment working of Grade II or above specified in GB/T 4200-2008;
c) Working environment with its average temperature lower than or equal to 5℃;
d) Works contacting cold water lower than or equal to 12℃;
e) Working place with slippery stuff such as ice, snow, frost, water and oil.
f) Working place with insufficient light, low visibility;
g) Distance from scope of working activity to the charged body of hazardous voltage less than those specified in Table1;
