Environmental Protection and ManagementAct(Chapter 94A, Section 77)EnvironmentalProtection and Management (Air Impurities) RegulationsRg 8G.N. No. S 595/2000REVISED EDITION 2008(31st January 2008)[1stJanuary 2001]Citation1. These Regulations may be citedas the Environmental Protection and Management (Air Impurities) Regulations. Dark smoke2. —(1) For the purposesof section 11 of the Act, dark smoke includes smoke of any colour whichappears to the Director-General or any authorised officer — (a)to be darker than shade No. 1 on theRingelmann Chart;(b)when observed or recorded with suchinstrument or device as the Director-General may approve, to be darker thanshade No. 1 on the Ringelmann Chart; or(c)to be of such opacity as to causeobscuration to a degree equivalent to smoke darker than shade No. 1 on theRingelmann Chart.(2) Section 11of the Act shall not apply to the emission of dark smoke from any chimneywhere — (a)the emission of dark smoke is for aduration of less than 5 minutes i...