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22. Regulations Concerning the Prevention of Explosions/Fires (Part 1)

As explosions/fires are taking place every year during the manufacture and/or handling of dangerous substances and single incidents can result in a number of victims in Japan, employers are required to take the following measures.

1.Measures in the case of manufacturing dangerous substances

a. Controlled substances and basic measures

(a) Explosive substances
  • Nitric esters, such as nitroglycol, nitroglycerin, and nitrocellulose
  • Nitro compounds, such as trinitrobenzene, trinitrotoluene, and picric acid
  • Organic peroxide, such as peracetic acid, methyl ethyl ketone peroxide, and benzoyl peroxide
  • Metal azides, such as sodium azide
(Basic measures)

Explosive substances shall not be placed close to fires or other ignition sources, heated or made subject to impact.

(b) Ignitable substances

  • Metallic lithium, metallic potassium, metallic sodium, yellow phosphorus, celluloid and the like, calcium carbide, magnesium powder, aluminum powder, etc.
(Basic measures)

Ignitable substances shall not be placed close to fires or other ignition sources, brought into contact with substances likely to give rise to oxidization or with water, heated or made subject to impact.

(c) Oxidizing substances

  • Chlorates and the like
  • Perchlorates and the like
  • Inorganic peroxides and the like
  • Nitrates and the like
  • Hypochlorites and the like
(Basic measures)

Oxidizing substances shall not be brought into contact with substances likely to give rise to chemical decomposition, heated, or made subject to friction or impact.

(d) Flammable substances

  • Substances with a flash point of less than 30 degrees C below zero, such as ethyl ether, gasoline, and carbon disulfide.
  • Substances with a flash point of 30 degrees C below zero or over and less than zero, such as normal hexane, ethylene oxide, and acetone.
  • Substances with a flash point of zero or over and less than 30 degrees C, such as methanol and xylene.
  • Substances with a flash point of 30 degrees C or over and less than 65 degrees C, such as kerosene, light oil, and acetic acid.
(Basic measures)

Flammable substances shall not be placed close to fires or other ignition sources , poured into containers, vaporized or heated.

(e) Combustible substances

(Basic measures)

Always putting everything in order, and not handling combustible or oxidizing substances without reason.

2.Measures for specified work, etc.

  1. Pouring inflammable liquid or combustible gas

    Making sure to confirm that all joints in a hose are tightened or properly set when pouring a liquid in chemical facilities, tank trucks, drums, etc., by using a hose.

  2. Pouring oil in a container having residual gasoline

    Making sure to secure a safe status when pouring kerosene or light oil in chemical facilities, tank trucks, drums, etc., in which residual gasoline may exist by cleaning the inside and replacing gasoline vapor by an inert gas or taking other appropriate measures in advance.

  3. Pouring and storing ethylene oxide

    Replacing the inside contents by an inert gas when poring or storing ethylene oxide, acetaldehyde, or propylene oxide in chemical facilities, tank trucks, drums, etc.

  4. Measures such as ventilation, letting fresh air in, etc.

    Taking such measures as ventilation, letting fresh air in, removing dust, etc., in places with a fear of explosions or fires due to the existence of flammable vapors, combustible gas or combustible dust.

  5. Measures for cases of gas welding, etc.

    Taking the following measures in cases of carrying out work such as welding, melt-cutting, metal heating, etc., by using combustible gas and oxygen.

    (a) Use a tightening tool such as a hose band and hose clip for connections between a gas hose, etc., and a blowpipe and/or between hoses.

    (b) Confirm that measures are taken to prevent gas from being emitted when supplying gas, etc., into a hose.

    (c) Attach the name card, etc., of the user to any open valves or cocks supplying gas, etc.

    (d) Thoroughly conduct ventilation to prevent burns resulting from the excessive supply of oxygen when conducting fusing work.

    (e) Close any open valves or cocks supplying gas when suspending or completing the work and remove the hose.

  6. Handling of gas cylinders, etc.

    (a) Do not install, use, store, or leave cylinders of gas, etc., at places when ventilation is inadequate, where fire is used, or where gun powders, dangerous substances, explosive or ignitable substances, etc., are manufactured.

    (b) Keep the temperature of a container at 40 degrees C or below.

    (c) Support cylinders in a stable manner, without any fear of overturning.

    (d) Do not subject the cylinders to impact.

    (e) Attach a cap when transporting cylinders.

    (f) Remove any oil, dust, etc., adhering to a mouth ring of a cylinder before use.

    (g) Avoid any abrupt handling in opening or closing a valve.

    (h) Place all cylinders containing solute acetylene in a vertical position.

    (i) Make a clear distinction between pre-use containers, containers being used and other containers

3.Measures for chemical facilities, etc.

  1. Anti-corrosion measures

    With respect to the portions of chemical facilities and/or their piping that come contact with dangerous substances or materials whose flash point is 65 degrees C or more, take such measures as using materials that are less prone to corrosion in accordance with the type, temperature, concentration, etc., of dangerous substances, etc., and lining such portions in order to prevent explosion and/or fires due to corrosion.

  2. Cover plate joints

    Use gaskets for joints of chemical facilities, their piping, flanges, cocks, etc., to ensure close fits of all joints in order to prevent explosions and/or fires due to the leakage of dangerous substances, etc.

  3. Indicating open-close directions

    Indicating the open-close directions, use different colors, or make distinctions in shape with respect to valves or cocks, or switches or push buttons for the operation of valves or cocks in order to prevent explosions and/or fires due to handling errors.

  4. Materials and the like of valves, etc.

    Use the following measures for valves and cocks.

    (a) Use durable materials in manufacturing valves and cocks in accordance with the type, temperature, concentration, etc., of dangerous substances.

    (b) Install valves and cocks in a double configuration between strainers, etc., that are often opened or removed during usage and the chemical facilities that are closest to such strainers.

  5. Indicating the types of raw materials

    Post labels indicating the types of raw materials to be supplied to chemical facilities and the target equipment for which such raw materials are supplied at easy-to-see locales.

  6. Measures for special chemical facilities (e.g., a reactor where exothermic reactions takes place)

    (a) Provide measuring instruments, such as thermometers, flow meters, manometers, etc.

    (b) Provide automatic alarm equipment or assign a watch-man for monitoring during operations in order to detect any internal abnormality at an early stage.

    (c) Provide equipment that suspends the supply of raw materials or release products, etc., in the event of any abnormality as well as equipment that supplies inert gas, coolants, etc.

    (d) Provide backup power sources.

    (e) Lock all valves, cock switches, etc., and classify by color and shape.

  7. Preparation of work manuals

    (a) Operation of valves, cocks, etc.

    (b) Operation of cooling devices, heating devices, agitators, and compressors.

    (c) Monitoring and adjustment of measuring instruments and control equipment.

    (d) Adjustment of safety valves, emergency cutoff equipment and other safety devices, as well as automatic alarm equipment.

    (e) Inspections to check if dangerous substances, etc., are leaking from the joints of cover plates, flanges, valves, cocks, etc.

    (f) Collection of samples

    (g) Work methods during work suspension or at the time of work resumption when special chemical facilities are temporarily and partially suspended.

    (h) Emergency measures in case of abnormalities

    (i) Other measures necessary to prevent explosions and/or fires

  8. Evacuation, etc.

    In the event of any imminent danger by explosion and/or fire when large volumes of dangerous substances, etc., are discharged from chemical facilities, etc., stop work immediately and evacuate workers to safe places.
    Prohibit entry by other than those concerned until all fear of possible industrial accidents is eliminated, and provide labels indicating such conditions at easy-to-see places.

  9. Measures in case of modifications, repairs, cleaning, etc.

    (a) Determine work methods and sequence and notify the workers concerned of the determined methods and sequence.

    (b) Assign an operation leader to carry out work

    (c) Double-close valves and cocks, or close valves and cocks and attach a stop plate, etc.

    (d) Lock valves, cocks, stop plates, etc., and attach labels indicating "Do Not Open", or assign a watchman.

    (e) In case stop plates, etc., are to be removed, confirm whether there are dangerous substances or high-temperature vapor at adjacent places.

  10. Periodic voluntary inspections

    Conduct voluntary inspections once every other year with respect to chemical facilities and auxiliary facilities. Store the records of inspections and repair results for three years.

  11. Safety devices

    With respect to containers where there is a fear that internal gas pressure may exceed the atmospheric pressure due to abnormal chemical reaction, containers other than those equipped with safety valves or safety devices must not be used.
    The structure of safety valves and safety devices must be air-tight, or have a structure that permits guiding discharged dangerous substances to safe places or permits safe processing by the burning or absorbing of such substances.

(The next issue will cover Regulations Concerning the Prevention of Explosions/Fires (Part 2))