Appendix A The Equivalent Chill Temperature Chart The equivalent chill temperature ECT chart relates the actual dry bulb temperature and the wind velocity The ECT often cal

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Appendix A The Equivalent Chill Temperature Chart The equivalent chill temperature ECT chart relates the actual dry bulb temperature and the wind velocity The ECT often cal Powered By Docstoc
					Appendix A:                    The Equivalent Chill Temperature Chart

The equivalent chill temperature (ECT) chart relates the actual dry bulb temperature and the wind
velocity. The ECT, often called the wind chill temperature, is a crucial factor to evaluate when
working outside. It should be used when estimating the combined cooling effect of wind and low air
temperature on exposed skin or when determining clothing insulation requirements.


 Estimated                                                     Actual temperature reading (°C)
 wind speed
                       10        5        0        -5       -10 -15 -20 -25 -30 -35                                     -40       -45           -50
  (in km/h)                                                  Equivalent chill temperature (°C)
  0 (Calm)             10        5         0        -5      -10 -15 -20 -25 -30 -35                                     -40       -45           -50
        8               9        3        -2        -7      -12 -18           -23        -28       -33       -38        -44       -49           -54
       16               4        -2       -7       -14 -20 -27                 -33       -38       -45       -50        -57        -63          -69
       24               2       -5       -11       -18 -25 -32                -38        -45       -52       -58        -65       -72           -78
       32               0       -7       -14       -21 -28 -35                -42        -50       -56       -64        -71       -78           -84
       40               -1      -8       -16       -24 -31 -38                -46        -53       -60       -67        -76       -82           -90
       48               -2     -10       -17       -25 -33 -40                -48        -55       -63       -70        -78       -86           -94
       56               -3     -11       -18       -26 -34 -42                -50        -58       -65       -73        -81       -89           -96
      64      -3 -11 -19 -27 -35 -43 -51                                                 -59       -66    -74 -82 -90          -98
(Wind speeds    LOW HAZARD         INCREASING                                                            HIGH HAZARD
 greater than Risk of exposed, dry   HAZARD                                                         Flesh may freeze within 30
64 km/h have skin being affected    Danger from                                                              seconds.
    little      in less than one     freezing of
  additional  hour. Awareness of    exposed flesh
   effect.)       hazard low.        within one
                                       minute.
(Source: British Columbia’s Cold Stress Regulation, Part 7)

The table was originally developed by the U.S. Army Research Institute of Environmental Medicine, Natick, MA, and is adapted from the 1995-1996
Threshold Limit Values for Chemical Substances and Physical Agents and Biological Exposure Indices, published by the ACGIH. The ACGIH
publication provides the equivalent table with temperature in degrees Fahrenheit and wind speed in mph.

Equivalent chill temperatures for actual temperatures and wind speeds not listed in this chart may be calculated by interpolation. For example, at a wind
speed of 16 km/h, an actual temperature reading of -23°C (3/5 of the difference between -20°C and -25°C) produces an equivalent chill temperature of -
36°C (3/5 of the difference between -33°C and -38°C).
Appendix B:                Work-Warming Schedule

If work is performed continuously in low temperatures and high wind conditions, the Threshold Limit Values (TLVs) of Work/Warm-up
Schedule should be consulted to determine the maximum length of a work period and number of work breaks.

 Air Temperature-              No Noticeable               8km/hr Wind               16km/hr Wind                24km/hr Wind               32km/hr Wind
    Sunny Sky                      Wind
                              Max.       No.             Max.      No.              Max.          No.          Max.          No.           Max.      No.
     o
         C (approx.)          Work        of             Work       of              Work           of          Work           of           Work       of
                             Period    Breaks           Period    Breaks           Period        Breaks       Period        Breaks        Period    Breaks
      -26 to -28             (Norm. Breaks) 1           (Norm. Breaks) 1           75 min          2          55 min          3           40 min      4
      -29 to -31             (Norm. Breaks) 1           75 min      2              55 min          3          40 min          4           30 min      5
      -32 to -34             75 min       2             55 min      3              40 min          4          30 min          5
      -35 to -37             55 min       3             40 min      4              30 min          5
      -38 to -39             40 min       4             30 min      5                                         Non – emergency             Non – emergency
      -40 to -42             30 min       5                                        Non – emergency            work should cease           work should cease
                                                        Non – emergency
     -43 & below             Non – emergency            work should cease          work should cease
                             work should cease
(Source: 1999 Threshold Limit Values for Chemical Substances and Physical Agents and Biological Exposure Indices, published by the ACGIH)

This schedule was developed by the Occupational Health and Safety Division of the Saskatchewan Department of Labour and adopted by the American
Conference of Governmental Industrial Hygienist (ACGIH).

Notes:

1.   Schedule applies to any 4-hour period with moderate to heavy work activity, with warm-up periods of 10 minutes in a warm location and with an extended
     break (e.g. lunch) at the end of the 4-hour work period in a warm location. For Light-to-Moderate Work (limited physical movement); apply the schedule
     one stem lower. For example, at –35oC (-30oF) with no noticeable wind, a worker at a job with little physical movement should have a maximum work
     period of 40 minutes with 4 breaks in a 4-hour period.

2.   The following is suggested as a guide for estimating wind velocity if accurate information is not available:
         8 km/hr: light flag moves; 16 km/hr: light flag fully extended; 24 km/hr: raises newspaper sheet; 32 km/hr: blowing and drifting snow

3.   TLVs apply only for workers in dry clothing.

Guidelines for the Prevention of Cold-Stress Related Injuries                                                                                      Page 6 of 7
      COLD STRESS HAZARDS INFORMATION SHEET

                               Cause                         Signs and Symptoms                                        Treatment                              Prevention
Frostbite          Frostbite is the formation of ice         Early warning symptoms include a cool           Move to a warm place and apply warmth     Wear woollen socks to protect your
                   crystals in exposed body parts. It        sensation in the affected area with the         to the affected parts.                    ankles and feet. Carry an extra pair
                   occurs when extremities such as           skin turning a lighter colour.                                                            of socks when moisture or sweating
                   the hands, feet, ears, and nose are                                                       Use a blanket and/or body heat to warm    is likely and change when needed.
                   exposed to cold for an extended           Pain in the extremities is usually the first    the person.
                   period of time.                           sign of danger. The affected part will also                                               Keep snow and water out of your
                                                             become pale and numb.                           DO NOT use alcohol as a warming agent.    footwear. Use silicone treatment for
                   Contact with gasoline, and some                                                                                                     leather boots.
                   cleaning fluids left outdoors can         Severe frostbite is characterized by hard       DO NOT submerse the person in hot
                   cause instant frostbite because           skin that has turned blotchy or blue.           water or a warm shower. This may result   Wear a face mask while working in
                   these liquids do not freeze when the                                                      in “re-warming shock”.                    cold wind.
                   temperature falls below the freezing
                   point.                                                                                    DO NOT rub the frostbitten area.          Wear mittens instead of gloves
                                                                                                                                                       whenever possible.


                   Hypothermia is the over cooling of        Early warning signs of hypothermia              SEEK MEDICAL ATTENTION.                   Move to a warm area periodically
Hypothermia        the body due to excessive loss of         include excessive shivering, blue lips and                                                throughout the day to ensure a
                   body heat. Although highly unlikely       fingertips, slurred speech and poor             Move the person to a warm shelter as      normal core body temperature is
                   under winter work conditions for City     coordination.                                   soon as you notice the warning signs of   maintained.
                   of Toronto employees, hypothermia                                                         hypothermia.
                   is a potentially fatal condition, which   More severe hypothermia impairs mental                                                    Wear multiple layers of light, loose-
                   requires      immediate        medical    functioning, resulting in confusion,            Use a blanket and/or body heat to warm    fitting clothes.
                   attention.                                disorientation and poor decision making.        the person.
                                                             At this stage the individual may have lost                                                Wear cotton or polypropylene long
                                                             all desire or ability to seek protection from   If conscious, give warm, non-alcoholic    underwear.
                                                             the cold, resulting in additional rapid loss    drinks in small quantities.
                                                             of body heat.                                                                             Wear waterproof/ water-resistant
                                                                                                             DO NOT use alcohol as a warming agent.    outerwear.

                                                                                                             DO NOT submerse the person in hot
                                                                                                             water or a warm shower. This may result
                                                                                                             in “re-warming shock”.




Guidelines for the Prevention of Cold-Stress Related Injuries                                                                                                                 Page 7 of 7

				
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