(1)The occupier of every humid factory shall, on or before the first occasion on which artificial humidity is produced at that factory, give notice thereof in writing to the chief inspector.
(2)The following provisions of this section shall have effect with respect to every humid factory with respect to which regulations under this Act concerning humidity are not for the time being in force.
[F1(2A)In this section—
“dry bulb temperature” means the temperature measured by an accurate and properly maintained thermometer (which may form part of the hygrometer) and any reference in this section to a dry bulb thermometer, or without qualification to a thermometer, shall be taken to be a reference to such a thermometer and a reference without qualification to temperature shall be taken to be a reference to the dry bulb temperature;
“hygrometer” means an accurate and properly maintained and calibrated instrument for the measurement of the relative humidity in the workplace;
“wet bulb temperature” means either—
the temperature indicated by the wet bulb of a static hygrometer which relies on natural circulation of air around the thermometers; or
the temperature calculated from the dry bulb temperature and relative humidity by the method approved for the time being by[F2 the Health and Safety Executive for Northern Ireland],
and any reference in this section to the reading of the wet bulb thermometer shall be treated as a reference to the wet bulb temperature.]
(3)There shall be provided and maintained in every room in which artificial humidity is produced two hygrometers[F1 and a thermometer close to each hygrometer]F1. . . , and—
(a)one of the hygrometers shall be[F1 placed] in the centre and the other at the side of the room, or in such other position as may be directed or sanctioned by an inspector, so as to be plainly visible to the persons employed;
Para. (b) rep. by SR 1992/461
(c)the occupier or other person authorised for the purpose shall read the hygrometers[F1 and the thermometers] between ten and eleven o'clock in the morning on every day on which any persons are employed in the room in the morning and between three and four o'clock in the afternoon on every day on which any persons are employed in the room in the afternoon, and when persons are employed before six o'clock in the morning or after eight o'clock in the evening, at such other times as may be directed by the chief inspector, and shall enter the readings on a record,F1. . . ;
[F1(d)the records of the wet bulb temperature or temperature and hygrometer readings shall be kept by the occupier for at least two years from when they were made and the occupier shall give his employees immediate access to those records on request together with such information as is necessary for their interpretation.]
(4)There shall be no artificial humidification in any room at any time when the reading of the wet bulb thermometer exceeds[F3 22.5 degrees Celsius], or, in the case of a room in which the spinning of cotton or the spinning of merino or cashmere by the French or dry process or the spinning or combing of wool by that process is carried on,[F3 26.5 degrees Celsius].
(5)There shall be no artificial humidification in any room at any time when the difference between the readings of the dry and wet bulb thermometers is less than that indicated[F1 in Schedule 1].
(6)Any water which is liable to cause injury to the health of the person employed, or to yield effluvia, shall not be used for artificial humidification, and for the purposes of this subsection any water which absorbs from acid solution of permanganate of potash in four hours at[F3 16 degrees Celsius] more than[F3 7 milligrams per litre of water] shall be deemed to be liable to cause injury to the health of the persons employed.
(7)The chief inspector may direct in writing, in the case of any factory or any room in a factory, that only one hygrometer,[F1 and one thermometer close to it placed] in such position as may be directed by an inspector, need be provided instead of two hygrometers[F1 and thermometers placed] as mentioned in subsection (3)( a).
(8)Where in respect of any room notice has been given in the prescribed manner to the chief inspector that it is intended that the humidity of the atmosphere should never be greater than will maintain a difference of at least[F3 2 degrees Celsius] between the readings of the dry and wet bulb thermometers, the provisions of subsection (3)( c) and ( d) shall not apply as respects that room so long as at least that difference is maintainedF1. . . .