# The Coal Mines (Precautions against Inflammable Dust) Order 1956, Paragraph 7


(1) For the purpose of establishing the efficacy of his arrangements made in pursuance of regulation five it shall be the duty of the manager of the mine to ensure that at intervals not exceeding thirty days a sufficient number of samples of the dust on every length of road to which that regulation applies are systematically collected and analysed.
(2) In the case of any such length of road which is used for the transport of coal or which is within six hundred feet of a working face and is used as a return airway in respect of that face, the number of samples so collected and analysed shall not be less than in the proportion of ten per mile:
Provided that an inspector may by notice served on the manager permit the taking and analysis of a lesser number of samples in any such length of road.
(3) If in the case of any length of road every analysis of a sample taken within the preceding six months indicates that the natural conditions of the road are such that the requisite percentage of incombustible matter is maintained without the application of incombustible dust or if, in the case of a length of road to which the last preceding paragraph does not apply, every such analysis indicates that the application of incombustible dust is not necessary at intervals of less than six months, it shall be sufficient for samples to be collected and analysed at intervals not exceeding ninety days or at such longer intervals as may be authorised by an inspector by notice served on the manager:
Provided that if there is any change in the natural conditions or in the method of working which affects or may affect substantially the percentage of incombustible matter in any such length of road, samples shall be taken and analysed as soon as any effect of the change would be apparent.
(4) The manager shall ensure that the result of every analysis required to be made by this regulation is within twenty-one days of the collection of the sample entered in a book provided by the owner of the mine for the purpose. Except at a mine at which less than one hundred persons are employed below ground, entries in that book relating to each length of road shall be distinguished by colour, number, letter or mark which shall be identified with that length of road by means of a suitable plan preserved with that book.
(5) The manager shall ensure that a notice specifying the result of every analysis required to be made by this regulation is kept in the covered accommodation provided in pursuance of section one hundred and thirty-five of the Act for a period of thirty days commencing when that result is entered in the book in pursuance of the last preceding paragraph.

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Source: https://www.legislation.gov.uk/uksi/1956/1769/schedule/paragraph/7 (the official version)
Page: https://openlegislation.uk/coal-mines-precautions-against-inflammable-dust-order-1956/schedule/paragraph-7
Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives.