MARVIN MANDEL, Governor                                       935

(E)   COURSING OF AIR.

(1)    SEPARATE OPENINGS.—THE MAIN INTAKE
AND MAIN RETURN AIR CURRENTS IN SLOPE MINES SHALL BE
IN SEPARATE OPENINGS.

(2)                                LIQUID-FILLED

TRANSFORMERS.--UNDERGROUND STABLES, BATTERY CHARGING

STATIONS, AND TRANSFORMER STATIONS CONTAINING
LIQUID-FILLED TRANSFORMERS SHALL BE WELL VENTILATED BY
SEPARATE SPLITS OF AIR CONDUCTED THROUGH VENTS TO THE
RETURN AIR COURSES AND RETURNING DIRECTLY TO THE
SURFACE.

(3)   CHANGES IN VENTILATION.--CHANGES IN

VENTILATION THAT MAY AFFECT THE SAFETY OF THE WORKERS
SHALL BE MADE WHEN THE MINE IS IDLE, WHEN NO WORKERS
OTHER THAN THOSE ENGAGED IN CHANGING THE VENTILATION
ARE IN THE MINE.

REVISOR'S NOTE: This subsection presently appears
as Article 66c, section 569(a) through (c),
inclusive, of the Code. The reference to
"June 1, 1949", is proposed for deletion as
obsolete. The only other changes made are
in style.

(F)   QUALITY OF AIR.—

(1)   DEFICIENCY OF OXYGEN AND EXCESS OF
CARBON DIOXIDE.—AIR IN MINES IN WHICH WORKERS WORK OR
TRAVEL SHALL BE IMPROVED IF IT CONTAINS LESS THAN 19.5
PERCENT OXYGEN, MORE THAN 0.75 PERCENT CARBON DIOXIDE,
OR IS CONTAMINATED WITH ANY NOXIOUS OR POISONOUS GAS.

(2)      EXCESS METHANE.—IF THE AIR
IMMEDIATELY RETURNING FROM A SPLIT THAT VENTILATES ANY
GROUP OF ACTIVE WORKINGS CONTAINS MORE THAN 1.0
PERCENT METHANE, AS DETERMINED WITH A PERMISSIBLE
FLAME SAFETY LAMP, BY AIR ANALYSIS OR BY OTHER
RECOGNIZED MEANS OF ACCURATE DETECTION, THE
VENTILATION SHALL BE IMPROVED.

(3)      EXCESS METHANE RETURNING FROM A

SPLIT.--IF THE AIR IMMEDIATELY RETURNING FROM A SPLIT

CONTAINS 1.5 PERCENT METHANE, A DANGEROUS CONDITION
EXISTS AND THE WORKERS SHALL BE WITHDRAWN FROM THE
MINE OR ITS AFFECTED PORTION. POWER SHALL BE CUT OFF
FROM THE MINE OR ITS AFFECTED PORTION UNTIL THE
DANGEROUS CONDITION HAS BEEN CORRECTED.