PERMITTED PERIODS OF DARK SMOKE _g S.L.200.01 1
SUBSIDIARY LEGISLATION 200.01
PERMITTED PERIODS OF DARK SMOKE 
REGULATIONS
15th April, 1969
LEGAL NOTICE 28 of 1969.
Title .
Smoke Regulations.
Interpretation. 
Cap. 200.
2.  Words and phrases used in these regulations shall have the
same meaning as is assigned to them in the Clean Air Act,
hereinafter referred to as "the Act".
Permitted period of 
emission of dark 
smoke.
3. (1) Emissions of dark smoke from any chimney (not being
a chimney of a vessel) for not longer than ten minutes in the
aggregate in any period of eight hours, or, if soot-blowing is carried
out within any such period, for not longer than fourteen minutes in
the aggregate in that period, shall be left out of account for the
purposes of article 3 of the Act.
(2) The said periods of ten minutes and fourteen minutes shall
be increased -
( a ) in the case of a chimney serving two furnaces, to
eighteen minutes and twenty-five minutes
respectively;
( b ) in the case of a chimney serving three furnaces, to
twenty-four minutes and thirty-four minutes
respectively; and
( c ) in the case of a chimney serving four or more furnaces,
to twenty-nine minutes and forty-one minutes
respectively.
(3) Nothing in the preceding sub-regulation shall authorise -
( a ) the continuous emission of dark smoke, caused
otherwise than by soot-blowing, for a period
exceeding four minutes, or
( b ) the emission of black smoke for more than two
minutes in the aggregate in any period of thirty
minutes.
(4) For the purposes of this regulation, where a single boiler or
unit of industrial plant is fired by more than one furnace
discharging to the same chimney, all those furnaces shall be
deemed to be one furnace.
(5) In this regulation, "black smoke" means smoke which, if
compared in the appropriate manner with a chart of the type known
at the date of enactment of the Act as the Ringelmann Chart, would
appear to be as dark as or darker than shade 4 on the Chart.
