Flammable liquids and liquified petroleum gases

• Since flammable liquids are used in many workplaces for a variety of reasons, OSHA’s requirements vary depending on exposure and other related factors.
• LPG is used in many workplaces for a variety of reasons and can pose a great hazard if not handled, used, and stored properly.
• Regulatory information for flammable liquids and LPGs can be found under 29 CFR 1910.

Flammable liquids

Flammable liquids are used in many workplaces for a variety of reasons. As their name implies, these liquids pose serious fire hazards if not handled, used, and stored properly. Flammable liquids are any liquid having a flashpoint at or below 199.4 °F (93 °C).

The Occupational Safety and Health Administration’s (OSHA’s) flammable liquids requirements apply to employers with employees who use or are exposed to flammable liquids. Depending on the type of work yielding the exposure, the quantities, and other factors, there are varying requirements. OSHA’s regulatory information for flammable liquids can be found under 29 CFR 1910.106.

What is required in the workplace?

In general, covered employers are required to:

• Properly design and install flammable liquid storage tanks;
• Properly design and install drainage, dikes, and walls for aboveground tanks;
• Use only approved containers for flammable liquids;
• Use only approved flammable storage cabinets (and do not exceed storage amount limitations);
• Follow the construction requirements for inside storage rooms;
• Follow flammable liquid storage amount limitations for warehouses or storage buildings;
• Follow flammable liquid storage amount limitations outside of buildings;
• Follow precautions to prevent the ignition of flammable vapors;
• Follow the requirements for providing appropriate firefighting equipment in areas where flammable liquids are stored and used; and

Employ the required maintenance and operating practices to control leakage and prevent the accidental escape of flammable liquids.

Liquified Petroleum Gases

Liquified Petroleum Gas (LPG) is used in many workplaces for a variety of reasons. LPGs are any material which is composed predominantly of (or a mixture of) propane, propylene, butanes (normal butane or iso-butane), and butylene. LPG poses a great hazard if not handled, used, and stored properly.

OSHA’s LPG requirements apply to employers who have employees who use or are exposed to LPG. Depending on the type of work yielding the exposure, the quantities, and other factors, there are varying requirements. OSHA’s regulatory information for LPGs can be found under 29 CFR 1910.110.

Exemptions from the regulation

This regulation does not apply to:

• Marine and pipeline terminals, natural gas processing plants, refineries, or tank farms other than those at industrial sites;
• LPG refrigerated storage systems;
• LPG when used with oxygen (The requirements of 1910.253 apply to such use);
• LPG when used in utility gas plants (For this usage, the National Fire Protection Association Standard for the Storage and Handling of Liquefied Petroleum Gases at Utility Gas Plants, (NFPA) No. 59-1968, will apply); or
• Low-pressure LPG piping systems (not in excess of one-half pound per square inch or 14 inches water column), and the installation and operation of residential and commercial appliances, including their inlet connections supplied through such systems. (For these systems, the National Fire Protection Association Standard for the Installation of Gas Appliances and Gas Piping, (NFPA) 54-1969 will apply).

What is required in the workplace?

In general, covered employers are required to:

• Properly design and install LPG tanks and containers;
• Properly design and install drainage, dikes, and walls for aboveground tanks;
• Use only approved containers for LPG;
• Follow the construction requirements for LPG tanks and containers;
• Follow LPG storage amount limitations for warehouses or storage buildings;
• Follow LPG storage amount limitations outside of buildings;
• Follow precautions to prevent the ignition of flammable vapors;
• Follow the requirements for providing appropriate firefighting equipment in areas where LPG is stored and used; and
• Employ the required maintenance and operating practices to control leakage and prevent the accidental escape of LPG.

Hydrogen

• Hydrogen is a compressed gas that is both an asphyxiant and an explosive that can lead to unconsciousness and burns if not used correctly.
• OSHA requirements apply to the installation of gaseous and liquified hydrogen systems on consumer premises.
• Regulatory information for hydrogen can be found under 29 CFR 1910.103.

Hydrogen is a compressed gas used in controlled atmospheres, fuel, metal cutting, and hydrogenation. The substance is an asphyxiant and an explosive. Exposure can lead to drowsiness and unconsciousness. Contact with hydrogen in liquid form may also cause severe burns and frostbite.

Regulatory information for hydrogen can be found under , but specific requirements from the Occupational Safety and Health Administration’s (OSHA’s) standard are as follows:

• 1910.103(b) — applies to the installation of gaseous hydrogen systems on consumer premises where the hydrogen supply to the consumer premises originates outside the consumer premises and is delivered by mobile equipment.
• 1910.103(b) — does not apply to gaseous hydrogen systems having a total hydrogen content of less than 400 cubic feet, nor to hydrogen manufacturing plants or other establishments operated by the hydrogen supplier or its agent for the purpose of storing hydrogen and refilling portable containers, trailers, mobile supply trucks, or tank cars.
• 1910.103(c) — applies to the installation of liquefied hydrogen systems on consumer premises.
• 1910.103(c) — does not apply to liquefied hydrogen portable containers of less than 150 liters (39.63 gallons) capacity; nor to liquefied hydrogen manufacturing plants or other establishments operated by the hydrogen supplier or its agent for the sole purpose of storing liquefied hydrogen and refilling portable containers, trailers, mobile supply trucks, or tank cars.

What is required in the workplace?

Employers must:

• Ensure gaseous system containers are designed, constructed, tested, and maintained in accordance with Department of Labor (DOT) specifications. (Systems should also be provided with substantial noncombustible supports);
• Ensure gas containers are marked;
• Ensure containers are equipped with safety relief devices. (See American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code, Section VIII);
• Only use suitable piping, tubing, fittings, and gauges;
• Mark the storage location as “HYDROGEN - FLAMMABLE GAS - NO SMOKING - NO OPEN FLAMES;”
• Locate systems per Table H-1 and H-2; and
• Ensure liquefied hydrogen storage is maintained per 1910.103(c)(2), including Table H-3.

Oxygen and acetylene

• Because of combustion hazards associated with oxygen, bulk oxygen systems must be carefully located, operated, and maintained to be safe.
• Acetylene poses a flammability hazard and must be used, transported, and stored properly for safety.
• Regulatory information for oxygen and acetylene can be found under 29 CFR 1910.

Oxygen

With the presence of oxygen, there is the hazard of combustion. Systems must be located in such a way that they are not near combustible or flammable material. The components of the systems must be constructed to operate safely for the intended application, complete with safety devices. A warning sign to indicate that no smoking or open flames are allowed must be permanently posted.

A bulk oxygen system is an assembly of equipment, such as oxygen storage containers, pressure regulators, safety devices, vaporizers, manifolds, and interconnecting piping which has storage capacity of:

• More than 13,000 cubic feet of oxygen connected in service or ready for service, or
• More than 25,000 cubic feet of oxygen, including unconnected reserves on hand. These quantities are maintained at normal temperature and pressure (NTP).

Where do the regulations apply?

The Occupational Safety and Health Administration’s (OSHA’s) regulatory information for oxygen can be found under 29 CFR 1910.104. This section applies to the installation of bulk oxygen systems on industrial and institutional consumer premises. This section does not apply to oxygen manufacturing plants or other establishments operated by the oxygen supplier or its agent for the purpose of storing oxygen and refilling portable containers, trailers, mobile supply trucks, or tank cars, nor to systems having capacities less than those stated in 1910.104(b)(1).

What is required in the workplace?

Employers with bulk oxygen systems must ensure the systems are located in an appropriate area. Bulk oxygen storage systems shall be located above ground outdoors, or shall be installed in a building of noncombustible construction, adequately vented, and used for that purpose exclusively. The location selected shall be such that containers and associated equipment shall not be exposed by electric power lines, flammable or combustible liquid lines, or flammable gas lines.

Employers must also:

• Ensure separation of systems and exposures as outlined in 1910.104;
• Equip containers with safety relief devices; and
• Maintain equipment in safe condition.

Acetylene

Acetylene has many industrial uses, from being a raw material to use in welding. The substance poses a flammability hazard and must be used, transported, and stored properly. The OSHA requirements apply to employers who have employees who use or are exposed to acetylene. The specific requirements vary depending on the application, but regulatory information for acetylene can be found under:

• 1910.102— Acetylene, and
• Related regulation: 1910.253— Oxygen-fuel gas welding and cutting.

What is required in the workplace?

Employers must follow the provisions of Compressed Gas Association (CGA) Pamphlet G-1-2009 for all in-plant transfer, handling, storage, and use of acetylene and must comply with Chapter 9 (“Acetylene Piping”) of NFPA 51A-2006 (“Standard for Acetylene Charging Plants”) (National Fire Protection Association, 2006 ed., 2006). Systems installed prior to Feb. 16, 2006, may comply with the provisions of Chapter 7 (“Acetylene Piping”) of NFPA 51A-2001 (“Standard for Acetylene Charging Plants”) (National Fire Protection Association, 2001 ed., 2001).

Employers must also:

• Ensure cylinder safety;
• Keep piped systems safe;
• Ensure that facilities, equipment, structures, or installations used to generate acetylene or to charge (fill) acetylene cylinders comply with the provisions of NFPA 51A-2006 (“Standard for Acetylene Charging Plants”) (National Fire Protection Association, 2006 ed., 2006), except for facilities constructed or installed prior to Feb. 16, 2006;
• Communicate hazard information through a hazard communication program; and Ensure cylinders are properly marked.

For welding applications, employers must follow the requirements in 1910.253.

Compressed gases

• Special storage, use, and handling precautions are necessary when dealing with compressed gases because of the chemical and physical hazards they pose.
• Employers that deal with compressed gases are required to become familiar with necessary safe practices and ensure all employees are properly trained and prepared, plus more.
• OSHA’s requirements for compressed gases apply to any employer whose facility has regulated compressed gases.

Compressed gases are a pressurized material or mixture in a cylinder, portable tank, or standing tank used in a variety of applications, including welding, refrigeration, heating, surgery, etc.

Hazards associated with compressed gases include oxygen displacement, fires, explosions, and toxic gas exposures, as well as the physical hazards associated with high pressure systems. Special storage, use, and handling precautions are necessary in order to control these hazards. Where do the regulations apply?

The Occupational Safety and Health Administration’s (OSHA’s) requirements for compressed gases apply to any employer whose facility has regulated compressed gases. Regulatory information for compressed gases can be found under 29 CFR 1910.101.

Related regulations include:

• 29 CFR 1910.102 — Acetylene
• 29 CFR 1910.103 — Hydrogen
• 29 CFR 1910.104 — Oxygen
• 29 CFR 1910.105 — Nitrous Oxide
• 29 CFR 1910.110 — Storage and Handling of Liquefied Petroleum Gases
• 29 CFR 1910.111 — Storage and Handling of Anhydrous Ammonia
• 29 CFR 1910.134 — Personal Protective Equipment
• 29 CFR 1910.169 — Air Receivers
• 29 CFR 1910.253 — Oxygen-fuel Gas Welding and Cutting
• 42 CFR 84 — Approval of Respiratory Protective Devices

What is required in the workplace?

Employers must:

• Determine if the workplace uses compressed gases;
• Become familiar with safe handling, use, and storage practices.
  • Pamphlets from the Compressed Gas Association are the primary guidance for compressed gas safety.
• Ensure all cylinders are inspected before use;
  • OSHA requires that employers inspect cylinders to determine if they are in a safe condition to the extent that it can be determined by visual inspection.
• Ensure only trained, authorized workers use compressed gases;
• Ensure only trained, authorized personnel conduct maintenance on a cylinder;
• Ensure labels and markings are present and not defaced;
  • Do not accept or use containers whose content labels are not legible. Segregate these containers and return them to the supplier.
• Ensure workers use safe handling, use, and storage practices;
• Train workers to report leaks immediately and follow proper safety procedures;
• Designate storage areas for various gases with adequate spacing or segregation by partitioning so that containers can be grouped by hazard;
• Prevent temperatures in the storage area from exceeding 125 °F;
• Separate cylinder storage from combustibles as specified by federal, state, and local regulations;
• Protect containers from cuts, punctures, or other abrasions of the metal, and keep heavy objects from striking or falling on them;
• Store containers away from walkways, elevators, stairs, and unprotected platform edges;
• Prevent unauthorized persons from tampering with the cylinders; and
• Only move compressed gas cylinders with a protective cap in place, unless the cylinder is mounted on a special truck and the cylinder is moved in an erect or nearly erect position.

Dipping and coating

• The chemicals used in dipping and coating operations may pose hazards to workers that range from fire risks to health risks.
• OSHA’s requirements apply when using a dip tank that contains any liquid other than water, but employers who use only molten materials are not covered.
• Employers are required to provide adequate ventilation, provide medical accommodations, and more to comply with regulations.

Dipping and coating operations are very common in many industries, particularly in terms of cleaning and coating. The process can pose hazards to workers, largely because of the chemicals used in the process. Potential risks from dripping and coating operations range from health hazards to flammability. The Occupational Safety and Health Administration’s (OSHA’s) dipping and coatings requirements apply when using a dip tank containing a liquid other than water. It applies when workers use the liquid in the tank or its vapor to:

• Clean an object,
• Coat an object,
• Alter the surface of an object, or
• Change the character of an object.

This rule also applies to the draining or drying of an object that has been dipped or coated.

OSHA’s regulatory information for dripping and coating can be found under:

• 29 CFR 1910.123 — Dipping and coating operations: Coverage and definitions
• 29 CFR 1910.124 — General requirements for dipping and coating operations
• 29 CFR 1910.125 — Additional requirements for dipping and coating operations that use flammable liquids or liquids with flashpoints greater than 199.4 °F (93 °C)
• 29 CFR 1910.126 — Additional requirements for special dipping and coating operations

Which operations are covered?

Examples of covered operations are paint dipping, electroplating, pickling, quenching, tanning, degreasing, stripping, cleaning, roll coating, flow coating, and curtain coating.

Employers are not covered by these requirements if their dip-tank operation only uses a molten material (a molten metal, alloy, or salt, for example).

What is required in the workplace?

Employers must:

• Assess their workplace for any dipping and coating operations;
• Provide adequate ventilation through various options, depending on the operation and chemical;
• Follow permit-required confined space requirements when employees enter a dip tank;
• Provide medical and first-aid solutions;
• Provide an eyewash/shower;
• Provide hygiene facilities, such as change rooms;
• Inspect exhaust ventilation at least quarterly and inspect dip tanks periodically;
• Follow the additional requirements in 1910.125 for dipping and coating operations that use flammable liquids or liquids with flashpoints greater than 199.4 °F (93 °C); and
• Follow the additional requirements in 1910.126 for special dipping and coating operations, such as hardening and tempering, flow coating, bonding and grounding, vapor degreasing, cyanide tanks, and spray cleaning and degreasing tanks.

Explosives and blasting and anhydrous ammonia

• Explosives are any chemical compound, mixture, or device whose purpose is to explode, while blasting agents are materials that blast but do not explode.
• Anhydrous ammonia is pure ammonia that is not mixed with water and is commonly used as a fertilizer or a refrigerant.
• Regulatory information for explosives/blasting agents and anhydrous ammonia can be found under 29 CFR 1910.

Explosives and blasting

The Occupational Safety and Health Administration (OSHA) defines explosives as any chemical compound, mixture, or device whose primary or common purpose is to function by explosion.This definition refers to explosives with a substantially instantaneous release of gas and heat, unless such compound, mixture, or device is otherwise specifically classified by the U.S. Department of Transportation (DOT).

A blasting agent is defined as any material or mixture of fuel and oxidizer that is used for blasting. Blasting agents and their ingredients are not classified as explosives. To meet definition requirements, the finished product, as mixed and packaged for use or shipment, cannot be denotated with a No. 8 blasting cap when unconfined.

Which regulations apply?

Regulatory information for explosives and blasting agents can be found under 29 CFR 1910.109. OSHA’s regulations apply to the manufacture, keeping, having, storage, sale, transportation, and use of explosives, blasting agents, and pyrotechnics. The section does not apply to the sale and use (public display) of pyrotechnics, commonly known as fireworks, nor the use of explosives in the form prescribed by the official U.S. Pharmacopeia.

What is required in the workplace?

Employers must follow requirements regarding:

• Storage of explosives - 1910.109(c);
• Transportation of explosives - 1910.109(d);
• Use of explosives and blasting agents - 1910.109(e);
• Explosives at piers, railway stations, and cars or vessels not otherwise specified in 1910.109 - 1910.109(f);
• Blasting agents - 1910.109(g);
• Water gel (slurry) explosives and blasting agents - 1910.109(h);
• Storage of ammonium nitrate - 1910.109(i); and
• Small arms ammunition, small arms primers, and small arms propellants - 1910.109(j).

Anhydrous ammonia

Anhydrous ammonia is a colorless, corrosive chemical that is lighter than air, extremely soluble in water, and has a piercing odor that is highly irritating. Most people are probably familiar with household ammonia, which is dissolved in water. In contrast, anhydrous ammonia is pure ammonia that is not mixed with water. Liquid anhydrous ammonia is a gas that is compressed into a liquid and has all the hazards of ammonia, but also has the hazards of a compressed gas.

Anhydrous ammonia is widely used as a fertilizer and refrigerant.

Where do the regulations apply?

OSHA’s standard on anhydrous ammonia applies to the design, construction, location, installation, and operation of anhydrous ammonia systems, including refrigerated ammonia storage systems. This standard does not apply to:

• Ammonia manufacturing plants, or
• Refrigeration plants where ammonia is used solely as a refrigerant.

Depending on the usage and quantities, OSHA’s Process Safety Management of Highly Hazardous Chemicals standard, 1910.119, could apply.

OSHA’s standard regulatory information for anhydrous ammonia can be found under:

• 29 CFR 1910.111 — Storage and handling of anhydrous ammonia.
• Related regulation: 29 CFR 1910.119 — Process safety management of highly hazardous chemicals.
• Related regulation: 29 CFR 1910.120 — Hazardous waste operations and emergency response (HAZWOPER).

What is required in the workplace?

Employers must:

• Determine if the anhydrous ammonia system contains a covered process for OSHA’s Process Safety Management (PSM) of Highly Hazardous Chemicals standard, 1910.119;
  • If the ammonia process, including those for ammonia refrigeration, has 10,000 pounds or more in a process, then 1910.119 applies.
• Follow the storage, use, and transfer requirements of 1910.111, as applicable;
• Provide appropriate personal protective equipment (PPE) for all workers exposed to anhydrous ammonia; and
• Implement an emergency response plan.

Process Safety Management

• PSM applies to companies that deal with any of 130 specific toxic and reactive chemicals in listed quantities and with certain flammable liquids or gases.
• The PSM standard does not apply to retail facilities, oil/gas well operations, or unoccupied remote facilities.
• Regulatory information for PSM can be found at 29 CFR 1910.119.

Occupational Safety and Health Administration’s (OSHA’s) Process Safety Management (PSM) of Highly Hazardous Chemicals standard contains requirements for the management of hazards associated with processes using chemicals deemed to be “highly hazardous.”

For many types of businesses, such as refineries and chemical companies, it may be obvious that PSM applies. However, PSM can apply to many other perhaps not-so-obvious employers, such as grocery stores, pulp mills, and manufacturers, to name a few. (Conversely, some employers think they have PSM-covered processes when, in fact, they do not.)

Where does PSM apply?

Regulatory information for PSM can be found under 29 CFR 1910.119— Process safety management of highly hazardous chemicals (PSM), including Appendix A — List of highly hazardous Chemicals, toxics and reactives.

PSM applies to those companies that deal with any of more than 130 specific toxic and reactive chemicals in listed quantities (See 1910.119 Appendix A, which contains the list); it also includes any Category 1 flammable gas (as defined in 1910.1200(c)) or a flammable liquid with a flashpoint below 100°F (37.8°C) on site in one location in a quantity of 10,000 pounds (4535.9 kg) or more (with a few exceptions, as outlined in 1910.119(a)(1)(ii)(A) and (B)).

Exempted from the standard

A few types of facilities and operations are exempt from PSM. The standard does not apply to any of the following:

• Retail facilities,
  • OSHA will typically not issue PSM citations to retail facilities, as those facilities generally do not present the same degree of hazard as other PSM workplaces. In particular, current OSHA policy specifically prohibits issuing PSM citations to employers in the following North American Industry Classification System (NAICS) codes:
    • 424510 - Grain and Field Bean Merchant Wholesalers,
    • 424590 - Other Farm Product Raw Material Merchant Wholesalers, and
    • 424910 - Farm Supplies Merchant Wholesalers.
• Oil or gas well drilling or servicing operations, and
• Normally unoccupied remote facilities.

This means that employees are not permanently stationed at the remote location. This includes sites where periodic visits by employees may be made on a scheduled basis. Examples could include pump stations that are located miles from the main establishment where employees may be assigned to check on the station as needed. The remote location must be geographically separated from other facilities and employees such that employees would not be affected by an explosion, vapor cloud of toxic gas, or other consequence of an uncontrolled release at the remote site.

Key definitions: Flammable liquids

• Familiarization with key terms associated with flammable liquids can help employers and employees avoid associated hazards.

It is important to recognize and be familiar with key terms and definitions related to flammable liquids so that potential hazards are understandable and clear.

• Aerosol: A material which is dispensed from its container as a mist, spray, or foam by a propellant under pressure.
• Approved: Unless otherwise indicated, approved or listed by a nationally recognized testing laboratory.
• Boiling point: The boiling point of a liquid at a pressure of 14.7 pounds per square inch absolute (p.s.i.a.) (760 mm.).
• Fire area: meansA separate area of a building constructed to have a fire resistance of at least 1 hour; communicating openings are properly protected by an assembly with a fire resistance rating of at least 1 hour.
• Flammable liquid: means anyAny liquid having a flashpoint at or below 199.4 °F (93 °C). Flammable liquids are divided into “categories” (they used to be divided into “classes,” but OSHA the Occupational Safety and Health Administration (OSHA) revised the standard in May 2012). The categories are:
  • Category 1 - includes liquids having flashpoints below 73.4 °F (23 °C) and having a boiling point at or below 95 °F (35 °C).
  • Category 2 - includes liquids having flashpoints below 73.4 °F (23 °C) and having a boiling point above 95 °F (35 °C).
  • Category 3 - includes liquids having flashpoints at or above 73.4 °F (23 °C) and at or below 140 °F (60 °C). When a Category 3 liquid with a flashpoint at or above 100 °F (37.8 °C) is heated for use to within 30 °F (16.7 °C) of its flashpoint, it must be handled in accordance with the requirements for a Category 3 liquid with a flashpoint below 100 °F (37.8 °C).
  • Category 4 - includes liquids having flashpoints above 140 °F (60 °C) and at or below 199.4 °F (93 °C). When a Category 4 flammable liquid is heated for use to within 30 °F (16.7 °C) of its flashpoint, it must be handled in accordance with the requirements for a Category 3 liquid with a flashpoint at or above 100 °F (37.8 °C).
  • When liquid with a flashpoint greater than 199.4 °F (93 °C) is heated for use to within 30 °F (16.7 °C) of its flashpoint, it must be handled in accordance with the requirements for a Category 4 flammable liquid.
• Flash point: is theThe lowest temperature at which the vapor of a substance will catch on fire. This measure provides an indication of how flammable a substance is.
• Portable tank: shall mean a A closed container having a liquid capacity over 60 U.S. gallons and not intended for fixed installation.
• Safety can: anAn approved container, of not more than 5 gallons capacity, having a spring-closing lid and spout cover and sothat is designed to that it will safely relieve internal pressure when subjected to fire exposure.
• Vapor pressure: shall mean theThe pressure, measured in pounds per square inch (absolute [p.s.i.a]) exerted by a volatile liquid as determined by the “Standard Method of Test for Vapor Pressure of Petroleum Products (Reid Method),” American Society for Testing and Materials (ASTM) D323-68, which is incorporated by reference as specified in Sec. 1910.6.
• Ventilation: as specified in this section is Necessary for the prevention of fire and explosion. It is considered adequate if it is sufficient to prevent accumulation of significant quantities of vapor-air mixtures in concentration over one-fourth of the lower flammable limit.

Key definitions: Liquified Petroleum Gas (LPG)

• Familiarization with key terms associated with LPGs can help employers and employees avoid associated hazards.

It is important to recognize and be familiar with key terms and definitions related to liquified petroleum gas (LPG) so that potential hazards are understandable and clear.

• API-ASME container: aA container designed, constructed, and tested in accordance with the Rules for Construction of Unfired Pressure Vessels, section VIII, Division 1, American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code, 1968 edition, which is incorporated by reference as specified in Sec. 1910.6.
• Approved: Unless otherwise indicated, listing or approval by a nationally recognized testing laboratory. Refer to 1910.7 for definition of nationally recognized testing laboratory.
• Container assembly: An assembly consisting of the container and fittings for all container openings, including shutoff valves, excess flow valves, liquid-level gaging devices, safety relief devices, and protective housing.
• Containers: All vessels, such as tanks, cylinders, or drums used for transportation or storing LPGs.
• DOT: Department of Transportation.
• DOT container: A container constructed in accordance with the applicable requirements of 49 CFR Chapter 1 (DOT Specifications).
• DOT cylinders: Cylinders meeting the requirements of 49 CFR Chapter I (DOT Specifications).
• DOT Specifications: Regulations of the Department of Transportation published in 49 CFR Chapter I.
• Liquefied petroleum gases (LPG and/or LP-Gas): Any material which is composed predominantly of any of the following hydrocarbons or mixtures of them: propane, propylene, butanes (normal butane or iso-butane), and butylenes.
• Listed: Unless otherwise indicated, listing or approval by a nationally recognized testing laboratory. Refer to 1910.7 for definition of nationally recognized testing laboratory.
• Movable fuel storage tenders or farm carts: Containers not in excess of 1,200 gallons water capacity that are equipped with wheels to be towed from one location of usage to another. These are nonhighway vehicles, but may occasionally be moved over public roads or highways. They are used as a fuel supply for farm tractors, construction machinery, and similar equipment.
• P.S.I.G.: Pounds per square inch gauge.
• P.S.I.A.: Pounds per square inch absolute.
• Systems: An assembly of equipment consisting of the container or containers, major devices such as vaporizers, safety relief valves, excess flow valves, regulators, and piping connecting such parts.
• Vaporizer (burner): An integral vaporizer-burner unit that is dependent upon the heat generated by the burner to vaporize the liquid used for dehydrators or dryers.
• Ventilation (adequate): When specified for the prevention of fire during normal operation, ventilation shall be considered adequate when the concentration of the gas in a gas-air mixture does not exceed 25 percent of the lower flammable limit.

Key definitions: Oxygen, acetylene, compressed gases, dipping and coating

• Familiarization with key terms associated with oxygen, acetylene, compressed gases, and dipping and coating can help employers and employees avoid associated hazards. It is important to recognize and be familiar with key terms and definitions related to oxygen, acetylene, compressed gases, and dipping and coating so that potential hazards are understandable and clear.

Oxygen

• Bulk oxygen system: A bulk oxygen system is an assembly of equipment that includes oxygen storage containers, pressure regulators, safety devices, vaporizers, manifolds, and interconnecting piping. A bulk storage system has a storage capacity of more than 13,000 cubic feet of oxygen, Normal Temperature and Pressure (NTP) connected in service or ready for service, or more than 25,000 cubic feet of oxygen (NTP), including unconnected reserves on hand at the site. The bulk oxygen system terminates at the point where oxygen at service pressure first enters the supply line. The oxygen containers may be stationary or movable, and the oxygen may be stored as gas or liquid.

Acetylene

• DOT: Department of Transportation. The government agency that prescribes requirements for design and marking of cylinders used in transport.
• CGA: Compressed Gas Association. The Occupational Safety and Health Administration (OSHA) references CGA pamphlets for most common acetylene requirements.
• NFPA: National Fire Protection Association. OSHA references NFPA codes for some aspects of acetylene safety.

Compressed gases

• Compressed gas: A gas which when under pressure is entirely gaseous at -50°C (-58°F), including all gases with a critical temperatureat 50°C (-58°F).
• Gases under pressure: Gases that are contained in a receptacle at a pressure of 200 kPa (29 p.s.i.) (gauge) or more, or which are liquefied or liquefied and refrigerated. They comprise compressed gases, liquefied gases, dissolved gases, and refrigerated liquefied gases.
• Inert gas: A gas which does not undergo a chemical reaction in a given situation. Argon and nitrogen are two common examples. Inert gases can still create a hazard by displacing oxygen in confined spaces.
• Flammable gas: A gas having a flammable range with air at 20°C (68°F) and a standard pressure of 101.3 kPa (kilopascal) (14.7 p.s.i.).
• Oxidizing gas: Any gas which may, generally by providing oxygen, cause or contribute to the combustion of other material more than air does.

Dipping and coating

• Adjacent area: Any area within 20 feet (6.1 m) of a vapor area that is not separated from the vapor area by tight partitions.
• Approved: The equipment so designated is listed or approved by a nationally recognized testing laboratory, as defined by 1910.7.
• Autoignition temperature: The minimum temperature required to cause self-sustained combustion, independent of any other source of heat.
• Dip tank: A container holding a liquid other than water that is used for dipping or coating. An object may be immersed (or partially immersed) in a dip tank or it may be suspended in a vapor coming from the tank.
• Flammable liquid: Any liquid having a flashpoint at or below 199.4 °F (93 °C).
• Flashpoint: The minimum temperature at which a liquid gives off a vapor in sufficient concentration to ignite if tested in accordance with the test methods in Appendix B to 1910.1200—Physical Hazard Criteria.
• Lower flammable limit (LFL): The lowest concentration of a material that will propagate a flame. The LFL is usually expressed as a percent by volume of the material in air (or other oxidant).
• Vapor: Any space containing a dip tank (including its drain boards), associated drying or conveying equipment, and any surrounding area where the vapor concentration exceeds 25 percent of the LFL of the liquid in the tank.

Key Definitions: Explosives and blasting

• Familiarization with key terms associated with explosives and blasting can help employers and employees avoid associated hazards.

It is important to recognize and be familiar with key terms and definitions related to explosives and blasting so that potential hazards are understandable and clear.

Blasting agent: Any material or mixture consisting of a fuel and oxidizer intended for blasting that is not otherwise classified as an explosive and in which none of the ingredients are classified as an explosive. The finished product, as mixed and packaged for use or shipment, cannot be detonated by means of a No. 8 test blasting cap when unconfined.

DOT specifications: Regulations of the Department of Transportation published in 49 CFR Chapter I.

Explosive-actuated power devices: Any tool or special mechanized device which is actuated by explosives, but not including propellant-actuated power devices. Examples of explosive-actuated power devices are jet tappers and jet perforators.

Explosive: Any chemical compound, mixture, or device whose primary or common purpose is to function by explosion, i.e., with substantially instantaneous release of gas and heat, unless such compound, mixture, or device is otherwise specifically classified by the U.S. Department of Transportation (DOT); see 49 CFR Chapter I. The term “explosives” shall include all material which is classified as Class A, Class B, and Class C explosives by the U.S. DOT, and includes, but is not limited to, dynamite, black powder, pellet powders, initiating explosives, blasting caps, electric blasting caps, safety fuse, fuse lighters, fuse igniters, squibs, cordeau detonant fuse, instantaneous fuse, igniter cord, igniters, small arms ammunition, small arms ammunition primers, smokeless propellant, cartridges for propellant-actuated power devices, and cartridges for industrial guns. Commercial explosives are those explosives which are intended to be used in commercial or industrial operations.

Magazine: Any building or structure, other than an explosives manufacturing building, used for the storage of explosives.

Propellant-actuated power devices: Any tool, special mechanized device, or gas generator system which is actuated by a smokeless propellant or which releases and directs work through a smokeless propellant charge.

Pyrotechnics: Any combustible or explosive compositions or manufactured articles designed and prepared for the purpose of producing audible or visible effects, commonly referred to as fireworks.

Semiconductive hose: A hose with an electrical resistance high enough to limit flow of stray electric currents to safe levels, yet not so high as to prevent drainage of static electric charges to ground; hoses of not more than 2 megohms resistance over its entire length and of not less than 5,000 ohms per foot meet the requirement.

Small arms ammunition: Any shotgun, rifle, pistol, or revolver cartridge, and cartridges for propellant-actuated power devices and industrial guns. Military-type ammunition containing explosive-bursting charges, incendiary, tracer, spotting, or pyrotechnic projectiles is excluded from this definition.

Small arms ammunition primers: Small percussion-sensitive explosive charges that are encased in a cup and used to ignite propellant powder.

Smokeless propellants: Solid propellants, commonly called smokeless powders in the trade, used in small arms ammunition, cannon, rockets, propellant-actuated power devices, etc.

Special industrial explosives devices: Explosive-actuated power devices and propellant-actuated power devices.

Special industrial explosives materials: Shaped materials, sheet forms, and various other extrusions, pellets, and packages of high explosives. These include dynamite, trinitrotoluene (TNT), pentaerythritol tetranitrate (PETN), hexahydro-1,3,5-trinitro-s-triazine (RDX), and other similar compounds used for high-energy-rate forming, expanding, and shaping in metal fabrication, and for dismemberment and quick reduction of scrap metal.

Water gels or slurry explosives: These comprise a wide variety of materials used for blasting. They all contain substantial proportions of water and high proportions of ammonium nitrate, some of which is in solution in the water. Two broad classes of water gels are (i) those which are sensitized by a material classed as an explosive, such as TNT or smokeless powder, (ii) those which contain no ingredient classified as an explosive; these are sensitized with metals such as aluminum or with other fuels. Water gels may be premixed at an explosives plant or mixed at the site immediately before delivery into the borehole.

Key Definitions: Anhydrous ammonia and hydrogen

• Familiarization with key terms associated with anhydrous ammonia and hydrogen can help employers and employees avoid associated hazards.

It is important to recognize and be familiar with key terms and definitions related to anhydrous ammonia and hydrogen so that potential hazards are understandable and clear.

Anhydrous Ammonia

• Appurtenances: All devices such as pumps, compressors, safety relief devices, liquid-level gaging devices, valves, and pressure gages.
• Cylinder: A container of 1,000 pounds of water capacity or less constructed in accordance with Department of Transportation (DOT) specifications.
• Code: The Boiler and Pressure Vessel Code, Section VIII, Unfired Pressure Vessels of the American Society of Mechanical Engineers (ASME) - 1968.
• Container: Includes all vessels, tanks, cylinders, or spheres used for transportation, storage, or application of anhydrous ammonia.
• DOT: U.S. Department of Transportation. 1910.111(a)(2)(vi).
• Design pressure: Identical to the term “Maximum Allowable Working Pressure” used in the Code.
• Farm vehicle (implement of husbandry): A vehicle for use on a farm that has a mounted container of not over 1,200 gallons water capacity.
• Filling density: The percent ratio of the weight of the gas in a container to the weight of water at 60 °F that the container will hold.
• Gas: Anhydrous ammonia in either the gaseous or liquefied state.
• Gas masks: Gas masks must be approved by the National Institute for Occupational Safety and Health (NIOSH) under 42 CFR part 84 for use with anhydrous ammonia.
• Capacity: Total volume of the container in standard U.S. gallons.
• DOT specifications: Regulations of the Department of Transportation published in 49 CFR Chapter I.
• Threshold quantity for Process Safety Management: 10,000 pounds in a process, as listed in 1910.119 Appendix A.

Hydrogen

• Gaseous hydrogen system: A system in which the hydrogen is delivered, stored, and discharged in the gaseous form to consumer’s piping. The system includes stationary or movable containers, pressure regulators, safety relief devices, manifolds, interconnecting piping, and controls. The system terminates at the point where hydrogen at service pressure first enters the consumer’s distribution piping
• Approved: Unless otherwise indicated, listed or approved by a nationally recognized testing laboratory. Refer to 1910.7 for definition of nationally recognized testing laboratory. ·
• Listed: See “approved”.
• ASME: American Society of Mechanical Engineers.
• DOT Specifications: Regulations of the Department of Transportation (DOT) published in 49 CFR Chapter I.

Key Definitions: Process Safety Management

• Familiarization with key terms associated with process safety management can help employers and employees avoid associated hazards.

It is important to recognize and be familiar with key terms and definitions related to process safety management (PSM) so that potential hazards are understandable and clear.

• Atmospheric tank: A storage tank designed to operate at pressures from atmospheric through 0.5 pounds per square inch gauge (p.s.i.g), 3.45 kPa (kilopascal).
• Boiling point: The boiling point of a liquid at a pressure of 14.7 pounds per square inch absolute (p.s.i.a.) (760 mm.). For the purposes of this section, where an accurate boiling point is unavailable for the material in question, or for mixtures which do not have a constant boiling point, the 10 percent point of a distillation performed in accordance with American Society for Testing and Materials (ASTM) D-86-62 may be used as the boiling point of the liquid.
• Catastrophic release: A major uncontrolled emission, fire, or explosion involving one or more highly hazardous chemicals that presents serious danger to employees in the workplace.
• Facility: The buildings, containers, or equipment which contain a process.
• Highly hazardous chemical (HHC): A substance possessing toxic, reactive, flammable, or explosive properties and specified by paragraph 1910.119(a)(1).
• Hot work: Work involving electric or gas welding, cutting, brazing, or similar flame or spark-producing operations.
• Normally unoccupied remote facility: A facility which is operated, maintained, or serviced by employees who visit the facility only periodically to check its operation and to perform necessary operating or maintenance tasks. No employees are permanently stationed at the facility. Facilities meeting this definition are not contiguous with, and must be geographically remote from, all other buildings, processes, or persons.
• One Percent Rule: The rule the Occupational Safety and Health Administration (OSHA) uses to determine if a mixture contains a covered volume of hazardous chemical. OSHA uses a one percent concentration cut-off.
• Process: Any activity involving an HHC including any use, storage, manufacturing, handling, or the on-site movement of such chemicals, or combination. For purposes of this definition, any group of vessels which are interconnected and separate vessels that are placed in a location where a highly hazardous chemical could be involved in a potential release are considered a single process.
• Replacement in kind: A replacement which satisfies the design specification.

Process Safety Management: Employer requirements

• Employers must ensure employee participation, keep records, conduct analyses, and more to ensure safety in the workplace and comply with regulation standards.

Employers with covered processes in Process Safety Management (PSM) must:

• Ensure employee participation in the PSM program,
• Compile information about the process,
  • Compiling written process safety information enables the employer and the employees involved in process operations to identify and understand the hazards posed by highly hazardous chemicals. This process safety information must include information pertaining to the hazards of the highly hazardous chemicals used or produced by the process, the technology of the process, and the equipment in the process.
• Conduct adequate process hazard analyses (PHA),
  • The type of method used needs to be analyzed thoroughly for compatibility with the process. After the initial PHA, employers must revalidate the analysis at least every five years.
• Implement safe operating procedures,
  • Operating procedures describe tasks to be performed, data to be recorded, operating conditions to be maintained, samples to be collected, and safety and health precautions to be taken. The procedures need to be technically accurate, understandable to employees, and revised periodically to ensure that they reflect current operations.
• Conduct process safety training,
  • All employees, including maintenance and contractor employees, involved with highly hazardous chemicals need to fully understand the safety and health hazards of the chemicals and processes they work with for the protection of themselves, their fellow employees, and the citizens of nearby communities. Training conducted in compliance with 1910.1200, the Hazard Communication standard, will help employees to be more knowledgeable about the chemicals they work with, as well as familiarize them with reading and understanding safety data sheets (SDSs). However, additional training in subjects such as operating procedures and safety work practices, emergency evacuation and response, safety procedures, routine and non-routine work authorization activities, and other areas pertinent to process safety and health will need to be covered by an employer’s training program.
• Ensure process safety for contractors,
  • Employers who use contractors to perform work in and around processes that involve highly hazardous chemicals will need to establish a screening process to ensure hired contractors don’t compromise the safety and health of employees at a facility.
• Conduct pre-startup safety reviews,
• Ensure integrity of process equipment,
  • Equipment used to process, store, or handle highly hazardous chemicals needs to be designed, constructed, installed, and maintained to minimize the risk of chemical releases. This requires that a mechanical integrity program be in place to assure the continued integrity of process equipment. Elements of a mechanical integrity program include the identification and categorization of equipment and instrumentation, inspection and test processes, testing and inspection frequencies, development of maintenance procedures, training of maintenance personnel, the establishment of criteria for acceptable test results, documentation of test and inspection results, and documentation of manufacturer recommendations as to mean time to failure for equipment and instrumentation.
• Ensure management of change process and procedures are adequate,
  • To properly manage changes to process chemicals, technology, equipment, and facilities, one must define what is meant by change. Change includes all modifications to equipment, procedures, raw materials, and processing conditions other than “replacement in kind.” These changes need to be properly managed through proper identification and review prior to implementation of the change. For example, the operating procedures contain the operating parameters (pressure limits, temperature ranges, flow rates, etc.) and the importance of operating within these limits. While the operator must have the flexibility to maintain safe operation within the established parameters, any operation outside of these parameters requires review and approval by a written management of change procedure.
• Investigate incidents per Occupational Safety and Health Administration (OSHA) requirements,
  • Incident investigation is the process of identifying the underlying causes of incidents and implementing steps to prevent similar events from occurring. This process allows employers to learn from past experiences and avoid repeating past mistakes. OSHA expects employers to become aware of and to investigate the types of events which result in or could reasonably have resulted in a catastrophic release. Some events are sometimes referred to as “near misses,” meaning that a serious consequence did not occur, but could have. Employers need to develop in-house capability to investigate incidents that occur in their facilities. A team needs to be assembled by the employer and trained in the techniques of investigation.
• Ensure emergency planning and response efforts are adequate, and
• Establish a process safety compliance audit process.
  • Employers need to select a trained individual or assemble a trained team of people to audit the PSM system and program at least once every three years. A small process or plant may need only one knowledgeable person to conduct an audit. The audit must include an evaluation of the design and effectiveness of the PSM system and a field inspection of safety and health conditions and practices to verify that the employer’s systems are effectively implemented. The audit should be conducted or led by a person knowledgeable in audit techniques who is impartial toward the facility or area being audited. The essential elements of an audit program include planning, staffing, conducting the audit, evaluation, corrective action, follow-up, and documentation.