73H. [ Special Safety Precautions for certain highly hazardous Chemical Process. [Inserted by G.N. dated 2nd July, 1976]
- In respect of any factory engaged in carrying out any hazardous chemical processes or such parts of any processes as are specified in the Schedule annexed hereto the following provisions shall be complied with viz.-(1)Process Hazards - Before commencing any large scale experimental works or any new manufacture, all possible steps shall be taken to ascertain definitely all the hazards involved both from the actual operations and also from the point of view of the chemical reactions. The properties of the raw materials used, the final products to be made and any byproducts arising during manufacture shall be carefully studied and adequate and suitable provisions shall be made in advance for dealing with any hazards including effects on workers which may be inherent in the process or which may arise during the process of manufacture.(b)The plant, machinery or equipment concerned with the hazardous process shall be in-charge of such operators only who have been trained and made thoroughly conversant to be fit persons to be incharge thereof and no other persons shall be allowed to operate the plant, machinery or equipment. The operators shall be regular employees of the Occupier and shall in no case be persons who are employed as contract workers.(c)The work of the operators shall be supervised on an overall basis by at least one competent person, who for the purpose of this sub-rule shall at least be graduate in Chemical Engineering or Chemical Technology with specialised knowledge in respect of the processes given in the schedule: Provided that the Chief Inspector of Factories may accept a graduate in chemistry having adequate knowledge of the processes given in the Schedule and also adequate experience and training or any other qualifications, if in his opinion they are equivalent to the qualifications aforesaid.(2)Emergency Instructions. - Simple and special instructions shall be framed to ensure that effective measures will be carried out in cases of emergency, to deal with possible escapes of inflammable explosive, toxic or deleterious gases, vapours, liquid or dusts. These instructions shall be in the language understood by the majority of the workers and shall be displayed in bold letters at prominent places in the different sections concerned. All concerned workers shall be suitably trained and fully instructed in the prompt action to be taken in such emergencies and also in the general hazards encountered in this process.(3)Fire and Explosion Risks. - In any part of the factory where there is a danger due to fire or explosion from inflammable gas, vapour or dust-(i)No internal combustion engine and no electric motor or other electrical equipment or instrument capable of generating sparks or otherwise causing combustion shall be installed or used in a building engaged in the processes. All electrical fitting shall be of suitable flame-proof construction.(ii)All pipes carrying hot exhaust or chemicals shall be installed outside the plant building and where this is not possible, these pipes including the flanged portion shall be effectively lagged.(iii)Where an inflammable atmosphere is likely to occur the soles of footwear worn by workers shall have no metal on them and the wheels of trucks or conveyors shall be constructed of non-sparking materials. Adequate precautions shall be taken to prevent the ignition of explosive or inflammable atmosphere by sparks emitted from locomotives or other vehicles operating in the vicinity.(iv)Portable electric hand lamps shall not be used unless of an intrinsically safe type and all portable electric tools and appliances connected by flexible wires shall not be used, unless these are of suitable flame-proof construction.(v)No electric arc lamp no naked light fixed or portable, shall be used and no person shall have in his possession any match or any apparatus of any type for producing a naked light or spark and all incandescent electric lights shall be in double airtight covers.(vi)Prominent notices in the language understood by the majority of the workers and legible by day and by night, prohibiting smoking, the use of naked lights and the carrying of matches or any apparatus for producing a naked light or spark shall be affixed at the entrance of every room or place where there is the risk of fire or explosion from inflammable liquid gas, vapour or dust. In the case of illiterate workers, the contents of the notices shall be fully and carefully explained to them when they commence work in the factory for the first time and again when they have completed one week of service.(vii)A sufficient supply of spades, scrapers and pails made from suitable non-sparking material shall be provided for the use of persons employed in cleaning out and/or removing residence from any chamber, still, tank or other vessels where any inflammable or explosive danger may occur.(viii)All machinery and plant, particularly pipe lines, belt-drives, stirer on which static electricity is likely to accumulate shall be effectively earthed. Receptacles for inflammable liquids shall have metallic connections to earthened supply tanks to prevent sparking due to static charge build up,(4)Additional Special Precautions. - (i) The heating of the process, if required, shall not be carried out by immersion or other types of heaters deriving energy from electricity.(ii)The steam heating coils placed in the lower part of the vessel shall never be kept uncovered or allowed to be heated dry. A substantial amount of the liquid shall be ensured in the vessel after each operation to insure this:Provided that in case employing out of vessels filled with high melting products, the steam shall be stopped/disconnected to the heating coils, before draining process is started to ensure that the heating coils are free of steam before they are uncovered.(iii)Steam shall be supplied through a pressure reducing valve and a safety valve correctly set to ensure that the critical temperature of the process is not exceeded.(iv)A suitable rupture disc shall be provided on the vessel in addition to the usual spring-loaded safety valve. The pipe duct leading away from the rupture disc shall be taken out of the work-room shall be straight and without any bends in order to minimise resistance at the time of blowing and to avoid any chance of a secondary vapour/air explosion.(v)The vent line of the vessel shall carry a flame-arrestor.(vi)Breaking of vacuum, if the process is done under vacuum, on account of consideration of special hazards inherent in the process, shall be done only with nitrogen, other suitable inert gas or steam. Compressed air 'connection to the manifolds of the vessel equipment shall be avoided.(vii)There shall be an automatic cut-off device of steam supply or other heating devices as well as of further feed to the vessel set to operate, no sooner the critical temperature is reached, beyond which the reaction, if any, in the vessels is likely to get out of control or reach run-away stage.(viii)There shall be arrangement such that it would be possible to introduce quickly, preferably chilled water or at least ordinary cool water circulation in the steam or other hearing coils, no sooner the hearing element is cut-off or separate coils or jackets for this purpose shall be provided for the vessel.(ix)An alarm system shall be provided linked to the pressure indicator of the vessel, so that automatically an audible warning will be given as soon as the pressure exceeds the present safe limit.(x)There shall be provided an automatic arrangement such that if the mechanical agitation, where so provided, fails on account of failure of motive power or due to broken shaft, broken blades, failing of blades or such other contingencies, the supply of steam or other heating devices as well as further feed of material would stop automatically.(5)Exemptions. - If the Chief Inspector of Factories is satisfied in respect of any factory or any process that owing to the special conditions or special methods of work adopted or by reason of the infrequency of the process or for other reasons, all or any of the requirement of this rule are not necessary for the protection of persons employed in any factory or any process, he may by order in writing (which he may in his discretion revoke at any time) exempt such factory or such process from all or any of the provisions of this rule, subject to such condition as he may by such order prescribe and he may, in his discretion add, substract or modify such conditions as deemed fit by him at any time.
