Wednesday, October 30, 2013

Job Hazard Analysis

What is a hazard?

A hazard is the potential for harm. In practical terms, a hazard often is associated with a condition or activity that, if left uncontrolled, can result in an injury or illness. See Appendix 2 for a list of common hazards and descriptions. Identifying hazards and eliminating or controlling them as early as possible will help prevent injuries and illnesses.

What is a job hazard analysis?

A job hazard analysis is a technique that focuses on job tasks as a way to identify hazards before they occur.
It focuses on the relationship between the worker, the task, the tools, and the work environment. Ideally, after you identify uncontrolled hazards, you will take steps to eliminate or reduce them to an acceptable risk level.

Why is job hazard analysis important?

Many workers are injured and killed at the workplace every day in the United States. Safety and health can add value to your business, your job, and your life. You can help prevent workplace injuries and illnesses by looking at your workplace operations, establishing proper job procedures, and ensuring that all employees are trained properly. One of the best ways to determine and establish proper work procedures is to conduct a job hazard analysis. A job hazard analysis is one component of the larger commitment of a safety and health management system. (See page 15 for more information on safety and health management systems.)

What is the value of a job hazard analysis?

Supervisors can use the findings of a job hazard analysis to eliminate and prevent hazards in their workplaces. This is likely to result in fewer worker injuries and illnesses; safer, more effective work methods; reduced workers’ compensation costs; and increased worker productivity. The analysis also can be a valuable tool for training new employees in the steps required to perform their jobs safely. For a job hazard analysis to be effective, management must demonstrate its commitment to safety and health and follow through to correct any uncontrolled hazards identified. Otherwise, management will lose credibility and  employees may hesitate to go to management when dangerous conditions threaten them.

Thursday, October 24, 2013

Sloping & Benching systems for excavations

May 2, 2013

Dear Mr. C***:

Thank you for your August 23, 2012 letter to the Occupational Safety and Health Administration (OSHA). We apologize for the delay in our reply. 

As you know, the State of California administers its own safety and health program under a plan approved and monitored by the Federal Occupational Safety and Health Administration (OSHA). As part of that program, the California Occupational Safety and Health Administration (Cal/OSHA), as part of the California Department of Labor, is responsible for the enforcement and interpretation of occupational safety and health regulations in that State. You may reach Cal/OSHA at:

Division of Occupational Safety and Health
1515 Clay Street, Suite 1901
Oakland, California 94612
Phone: (510) 286-7000
Fax: (510) 286-7037

Federal OSHA regulations governing sloping and benching systems for excavations

Your August 23, 2012 letter and subsequent discussions with Directorate of Construction (DOC) staff raise two specific questions regarding OSHA's excavation standard. This letter constitutes OSHA's interpretation of only the requirements discussed and may not be applicable to any question not delineated in your original correspondence. 

We have paraphrased your questions as follows:
Question 1: If the employer elects Option (4) of 29 CFR 1926.652(b) to provide the protective system for his excavation, and he retains a registered professional engineer (RPE) to design the slope and bench configurations, is the RPE design bound by the requirements and provisions of Appendix B to Subpart P of Part 1926 -- Sloping and Benching?

Response 1: No. 29 CFR 1926.652(b)(4) Option (4) - Design by a registered professional engineer, provides that:
  1. Sloping and benching systems not utilizing Option (1) or Option (2) or Option (3) under paragraph (b) of this section shall be approved by a registered profession engineer.
  2. Designs shall be in written form and shall include at least the following:
    1. The magnitude of the slopes that were determined to be safe for the particular project;
    2. The configurations that were determined to be safe for the particular project; and. . .
In addition, the preamble to the final rule of 29 CFR 1926.652(b)(4) Option (4) (54 FR 45929; October 31, 1989) further explains that:
Under this option . . . It provides no specific restrictions as to maximum allowed slopes or configurations that a registered professional engineer might design or approve . . . slopes steeper than those allowed under the other options could be used. Configurations different from those allowed under the other options could also be used.
Question 2: The employer's RPE specified the soil as Type A and designed a sloping and benching configuration for an excavation 14 feet deep. It consists of 3 feet unsupported vertical sides at the lower portions of the excavation and 11 feet sloped cuts with ¾ horizontal to 1 vertical at the upper portion of the excavation. In addition, in your September 14, 2012 discussions with DOC staff, you indicated that the excavation for the particular project is intended to station (house) the pile driving equipment. Is this configuration in compliance with the excavation standard?

Response 2: OSHA is precluded from approving or endorsing specific products, services, or analyses. The variable working conditions at job sites and possible alteration or misapplication of an otherwise safe piece of equipment, service, or system, could easily create a hazardous condition. However, where appropriate, we try to give some guidance to help employers assess whether products, services, or analyses are appropriate to use in light of OSHA requirements. 

The employer's RPE must consider site and environmental conditions, specifically taking into account the stresses that vibrations cause. It is not clear that this RPE configuration takes the vibrations into account, as it specifies "Type A" soil. "Type A" is defined in Appendix A to Subpart P of Part 1926 - Soil Classification, Section (b) Definitions:
Type A means cohesive soils with an unconfined compressive strength of 1.5 ton per square foot (tsf) (144 kPa) or greater. . . . However, no soil is Type A if:
  1. The soil is fissured; or
  2. The soil is subject to vibration from heavy traffic, pile driving, or similar effects; or . . .
Thus, even if a soil has an unconfined compressive strength of 1.5 tsf or greater as Type A, but if this soil is subject to vibration, such as pile driving activities, the soil cannot be considered as Type A. Therefore, this RPE configuration may not be appropriate for the intended use of the excavation, and may need to be modified.

Friday, October 18, 2013

Ammonium Nitrate (AN): Safe Storage, Handling, & Management Part 4

Emergency Response

Owner/operators of storage facilities should develop a site emergency response plan which includes:

• Coordination with local first responders
• Joint training with first responders if possible
• Employee training
• Community outreach
• Analysis of what may be at risk in a serious accident and appropriate planning
• Signs that clearly mark high hazard areas, safe areas, emergency contact numbers, firefighting equipment, and other essential area during an emergency response
• A site and area evacuation plan

Owners and operators of facilities holding AN have an obligation to ensure their community’s first responders are aware of the hazards associated with the AN. Reliance on a report may not always be sufficient. Owners and operators should take a pro-active approach to reaching out to the emergency response officials in their location and ensuring that the hazards of AN are understood by the responders.

What do firefighters need to know when responding to an accident or fire involving AN?

Before responding to a fire involving AN, firefighters should ensure the community emergency response plan includes:

• AN hazard information and emergency response guidelines
• Quantity, storage types, and locations of AN at facilities in their community
• Specific response procedures; including a decision process to determine under which conditions a fire should be fought or whether the fire should be allowed to burn
• Evacuation procedures for the community
• Training requirements for all response personnel
• A schedule for exercising the response plan related to AN accidents

When responding to a fire where AN is stored; firefighters should:

• First consider if they can safely fight the fire or whether they should just let it burn, move to a safe location, and focus on evacuating nearby residents and preventing further safety issues for the surrounding community.

To determine whether or not it makes sense to fight the fire or to let it burn, firefighters and emergency responders should consider the following information:

• Firefighters should not fight an AN fire and everyone, including fire fighters, should be evacuated to a safe distance if they observe any of the following:
o A fire involving AN is judged to be out of control;
o The fire is engulfing the AN; or
o Brown/orange smoke is detected, indicating the presence of nitrogen dioxide (which is toxic); or
o A rapid increase in the amount/intensity of smoke or fire in the area of AN storage.

• If firefighters consider it safe and appropriate to respond to a fire involving AN, then the following information should be considered:
o AN fires should be fought from protected locations or maximum possible distance. Approach a fire involving or close to AN from upwind to avoid hazardous vapors and toxic decomposition products. Self-contained breathing apparatus (SCBA) of types approved by the National Institute for Occupational Safety and Health (NIOSH) should be used to protect personnel against gases.
o Use flooding quantities of water from a distance as promptly as possible. It is important that the mass of AN be kept cool and the burning be quickly extinguished. Keep adjacent fertilizers cool by spraying with large amounts of water. When possible and appropriate, only use unmanned hose holders or monitor nozzles.
o Do NOT use steam, CO2, dry powder or foam extinguishers, sand or other smothering agents.
o Ensure maximum ventilation of the AN storage container as quickly as practical to prevent heat and pressure buildup. This is different than ensuring maximum ventilation of the entire building or structure where the AN is stored. Ventilation of the structure should be conducted only in a manner to limit fire spread and growth and should be minimized until a suppression water supply is established.
o If practicable and safe to do so, attempt to prevent AN from entering the drains where explosive confinement could occur. Remember AN may be washed into drains by fire water, but it can also melt and flow without impetus from water.
o Prevent or minimize contamination of water bodies or streams to reduce the potential for environmental effects.

Friday, October 11, 2013

Ammonium Nitrate (AN): Safe Storage, Handling, & Management Part 3

Community Emergency Planning

What should communities do to understand and develop a plan for the risk associated with AN?

AN is a hazardous chemical covered under the OSHA Hazard Communication Standard. Therefore, facilities that handle and store AN are required by law to submit information regarding chemical hazards (including AN) to their State or Tribal Emergency Response Commission (SERC or TERC), Local Emergency Planning Committee (LEPC), and local fire department. This information must include the following:

1) a Safety Data Sheets (SDS) providing the chemical’s hazard information and emergency response guidelines and
2) a Hazardous Chemical Inventory form that provides the quantity, storage types and locations of the AN at their facility.

We recommend that fire services visit any facility reporting AN, and that the conditions of storage and manner of handling be reviewed by fire service personnel. Fire service and other emergency responders should take note of the specific location(s), amounts and packaging of stored AN. Conditions of storage should be reviewed with the facility operator in light of the information provided in this document.

The LEPC in conjunction with the fire department should use this information to develop an emergency plan, in case of a fire or explosion involving AN or any other hazardous substance. The facility should consult with the LEPC to provide them the necessary information to develop the emergency plan, the elements of which should include:

• Identification of facilities and transportation routes of hazardous substances
• Description of emergency response procedures, on and off site
• Designation of a community coordinator and facility emergency coordinator(s) to implement the plan
Outline of emergency notification procedures
• Description of how to determine the probable area and population affected by releases
• Description of local emergency equipment and facilities and the persons responsible for them
• Outline of evacuation plans
• A training program for emergency responders (including schedules)
• Methods and schedules for exercising emergency response plans

LEPCs should also ensure that members of the community (which would include potentially affected populations) are aware of the emergency plan and the actions they need to take if an accident occurs.

Local fire departments should use the information to determine what precautions they may need to take in responding to an accident at the facility and ensure the first responders have the appropriate training to respond to incidents involving AN.

Owners and operators of facilities holding AN are required to report the AN hazard to local response officials under the Emergency Planning and Community Right-to-Know Act (EPCRA). Unfortunately, that obligation is not universally understood, and so some facilities may fail to report. Fertilizer-grade AN is typically found at those businesses that provide direct logistical support to agriculture. This may include crop service operations, farm co-ops, grange stores and similar operations.

In the interest of community safety, it is often necessary and appropriate for first response officials to reach out to facility owners and operators, and determine if unreported risks are present in their community. Helping a neighbor, facility operator, or employer to understand and meet his obligations to the community and to workers is in everyone’s best interest

Monday, October 7, 2013

Ammonium Nitrate (AN): Safe Storage, Handling, & Management Part 2

What steps should facility owners or operators take to reduce the hazards of AN during storage and handling?
Storage/Process Conditions to Avoid
Persons engaged in the handling, management or emergency planning for AN must be aware of the hazards of AN and ensure that the conditions that may lead to an explosion are not present. Measures that facilities should take to ensure the safe storage, use and handling of AN include:
  • Avoid heating AN in a confined space.
    • Processes involving AN should be designed to avoid this possibility.
    • Avoid localized heating of AN, potentially leading to development of high temperature areas (e.g., AN fertilizer should not be stored near sources of heat such as steam pipes, radiators, hot ducts, light bulbs etc.).
  • Ensure that AN is not exposed to strong shock waves from explosives. AN storage near high explosives or blasting agents must conform to ATF's Table of Separation Distances, Title 22 of the Code of Federal Regulations, section 555.220 (22 CFR 555.220).
  • Avoid contamination of AN with combustible materials or organic substances such as packing materials, dust, seed, oils, and waxes.
    • If possible, do not co-locate AN, especially bulk AN in bins, with dust-producing organics such as grains or seeds.
  • Avoid contamination of AN with inorganic materials that may contribute to its sensitivity to explosion, including chlorides and some metals, such as aluminum powder, chromium, copper, cobalt, and nickel.
    • Pay attention to the materials used to build storage areas and cribs. Wood and aluminum or other metals must be specially treated to prevent impregnation if they are going to be in contact with AN. Metal materials can be treated with epoxy tar or chlorinated rubbers to prevent corrosion of the metal and contamination of the AN.
  • Maintain the pH of AN solutions within the safe operating range of the process. In particular, avoid low pH (acidic) conditions.
    • If possible, do not co-locate acids in an AN storage area.
  • Keep molten or solid AN out of confined spaces, especially sewers or drains where it can react with organic materials there.
Certain specific safety and handling instructions (required and recommended) apply for safe handling and storage of AN6 under certain conditions:

OSHA's standard for Explosives and Blasting Agents at 29 CFR 1910.109(i) contains requirements for AN stored in the form of crystals, flakes, grains or prills including fertilizer grade, dynamite grade, nitrous oxide grade, technical grade, and other mixtures containing 60 percent or more of AN by weight. AN should also be handled in accordance with safe practices found in NFPA 400 Hazardous Materials Code, Chapter 11.
Building Design
  • Store only in one-story buildings and buildings with no basements, unless the basement is open on one side.
  • Use fire resistant walls within 50 feet of combustible building or materials.
  • Flooring in storage and handling areas should be constructed of noncombustible material or protected from impregnation by AN.
  • Avoid installing, or remove or close off any open drains, traps, tunnels, pits or pockets into which molten AN can flow and be confined in the event of fire.
  • Buildings should be kept dry and free of water seepage through roofs, walls and floors.
  • Have adequate ventilation or be constructed to self-ventilate in the event of a fire to avoid pressurization.
  • Do not place AN into storage when the temperature of the product exceeds 130°F (54.4°C).
Storage in bags, drums or other containers
  • Piles of bags, drums and other containers should be no closer than 36 inches below the roof or supporting beams.
  • Bags should be stored no less than 30 inches from walls or partitions.
  • Piles of bags, drums, and other containers should not exceed a height of 20 feet, width of 20 feet, and length of 50 feet, unless the building is of noncombustible construction or protected by automatic sprinklers.
  • Maintain aisles of at least 3 feet width between piles.
Storage in bulk
Bins for storing bulk AN should be kept clean and free of materials, which could contaminate the material. Bins should not be constructed of galvanized iron, copper, lead or zinc unless suitably protected. Aluminum or wooden bins should be protected against impregnation by AN.

  • Piles or bins must be adequately sized, arranged and moved periodically to minimize caking. Height or depth of piles shall be limited by pressure-setting tendency of the product, but in no case should pile be higher than 36 inches below roof or supporting beams.
  • Do NOT use dynamite, explosives or blasting agents to break up or loosen caked AN.
  • Protect piles of AN from absorbing moisture from humid air by covering them with water-impermeable sheeting or using air conditioning.
  • Do not store AN with organic chemicals, acids, or other corrosive materials, materials that may require blasting during processing or handling, compressed flammable gases, flammable and combustible materials or other contaminating substances. AN stores should be separated from incompatible substances by using separate buildings or 1 – hour fire resistant walls, or a minimum separation distance of 30 feet.
Fire Protection
  • AN storage areas should be equipped with an automatic sprinkler system, or have an automatic fire detection and alarm system if the areas are not continuously occupied. This is especially important when the facility in question is close to the public surrounding the facility.
  • Facilities should NOT store more than 2500 tons of bagged AN without an automatic sprinkler system.
  • An automatic sprinkler system, if installed, should be provided in accordance with NFPA 13, Standard for the Installation of Sprinkler Systems.
  • Suitable fire control devices such as hoses and appropriate portable fire extinguishers (AN is an oxidizer and not all fire extinguishers are appropriate) shall be provided throughout the warehouse and loading areas. Water supplies and fire hydrants should be available.
  • Store AN fertilizer in separate buildings or separated by approved fire walls from organic, combustible or reactive materials, such as grains, wood or other organic materials, urea and urea compounds, flammable liquids or gases, corrosive acids, chlorates, chromates nitrites, permanganates or finely divided metals or sulfur.

  • AN fertilizer should NOT be stored in the same building with explosives or blasting agents unless conditions in ATF's Table of Separation Distances of Ammonium Nitrate and Blasting Agents from Explosives and Blasting Agents, 27 CFR 555.220, are met.
  • Prohibit smoking in AN storage areas.

  • We recommend that AN be stored in purpose-built facilities/buildings of non-combustible construction. Dust-producing organic materials, such as grain, seeds and sugar, should not be stored near AN. Some metal powders such as aluminum powder are equally dangerous. AN should be stored so as to ensure it is not contaminated by gasoline, diesel or other fuels, and is not subject to high heat (even in one small area of a large stockpile) or water infiltration.

    Wednesday, October 2, 2013

    Ammonium Nitrate (AN): Safe Storage, Handling, & Management

    Information On Hazards

    Hazard Classification

    For the purpose of transportation, AN that contains less than 0.2 percent combustible substances and AN fertilizers are classified by the U.S. Department of Transportation (DOT), as oxidizers. AN with more than 0.2 percent combustible substances is classified by DOT as an explosive.5 (see box below).

    The National Fire Protection Association (NFPA) assigns an instability rating of 3 (in a range of 0-4) to AN, meaning AN is capable of detonation, explosive decomposition, or explosive reaction, but that a strong initiating source or confinement in extreme temperatures is required. AN can explode under certain conditions by adding energy (heat, shock), especially when contaminants are present or it is under confinement.

    “Pure” ammonium nitrate is stable and will explode only under extraordinary circumstances. However, the addition of combustible materials such as sugar, grain dust, seed husks or other organic contaminants, even in fairly low percentages, creates a dangerous combination and the ammonium nitrate mixture becomes far more susceptible to detonation. This characteristic of ammonium nitrate underlies most of the advice and recommendations for safe handling contained herein.

    Decomposition Chemistry

    AN melts at 337° F (170° C) and begins to undergo decomposition when molten. Hazardous scenarios with AN can involve simple thermal decomposition initiated by external fire or other heating, self-sustained decomposition also known as “cigar burning,” and detonation.

    Decomposition creates toxic gases containing ammonia and nitrogen oxides. The resulting nitrogen oxides will support combustion, even in the absence of other oxygen. The resulting heat and pressure from the decomposition of AN may build up if the reaction takes place in a confined space and the heat and gases created are not able to dissipate. As the temperature rises, the rate of decomposition increases. In a confined space, the pressure can reach dangerous levels and cause an explosion that will include the detonation of the AN.

    When dealing with a large quantity of AN, localized areas of high temperature may be sufficiently confined by the mass of material to initiate an explosion. The explosion of a small quantity of AN in a confined space (e.g., a pipe) may act as a booster charge and initiate the explosion of larger quantities (e.g., in an associated vessel).

    During a fire in a facility where AN is present, the AN can become hot and molten which makes the material very sensitive to shock and detonation, particularly if it becomes contaminated with incompatible material such as combustibles, flammable liquids, acids, chlorates, chlorides, sulfur, metals, charcoal, sawdust, etc. If a molten mass becomes confined (e.g., in drains, pipes or machinery), it can explode.

    Most types of AN do not continue to decompose once a fire has been extinguished. However, some types of AN fertilizers containing a small percentage of chlorides (e.g., potassium chloride) undergo a smoldering (self-sustaining) decomposition that can spread throughout the mass to produce substantial toxic fumes, even when the initial heat source is removed. These fertilizers that can self-sustain decomposition, known as “cigar burners” are normally compound fertilizers that contain between 5% to 25% nitrogen from ammonium nitrate, up to 20% phosphate (as P2O5) and chloride (which may only be present as a small percentage).


    AN mixed with oil or other sensitizing contaminants may explode or detonate when exposed to fire or shock. Organic materials (e.g., packing materials, seed, etc.) will increase the likelihood of an explosion and will make the AN explosion more energetic.

    AN may also be sensitized by certain inorganic contaminants, including chlorides and some metals, such as aluminum powder, chromium, copper, cobalt, and nickel.

    As AN solution becomes more acidic, its stability decreases, and it may be more likely to explode.
    Solid AN readily absorbs moisture, which can lead to caking, self-compression and self confinement. This in turn increases susceptibility to explosion in a fire.

    The density, particle size and concentration of solid AN in a material, as well as the presence of other additives, affects the hazard of the material. The technical grade of AN is a lower density (higher porosity) prilled material. Higher density prills are used as fertilizer. AN can be fused with ammonium sulfate fertilizer or amended with carbonate materials to reduce its explosive properties. More information on additives is discussed in Guidance for the Storage, Handling and Transportation of Solid Mineral Fertilizers found in the Reference section. Solid fertilizers are usually coated with an inorganic, non-combustible anti-caking compound to prevent sticking and clumping. AN in undiluted or pure form has a higher degree of overall hazard than when it is mixed or blended with compatible or non-combustible materials that can reduce the concentration. In general for fertilizer blends containing AN, the more nitrogen they contain, the greater the explosion hazard they pose. Blended fertilizers containing AN and chloride compounds and blended fertilizers containing AN contaminated with combustible materials or incompatible substances pose increased explosion hazards. A large number of blended fertilizers are produced from basic primary fertilizer products (e.g., ammonium nitrate, urea, and mono-ammonium phosphate) and natural materials (e.g., rock phosphate, potassium chloride) which can introduce contaminants. All such materials are not necessarily compatible with each other and some may produce undesirable effects when mixed with others. These undesirable effects can include, for example, chemical reaction(s) and physical effects (e.g. stickiness which can cause handling difficulties, moisture migration giving rise to caking tendency). Facilities can consult Guidance for Compatibility of Fertilizer Blending Materials listed in the Reference section to assess potential incompatibility. The Safety Data Sheet (SDS – formerly MSDS) of the AN product should be used as one source of information to assess the overall hazard. The effects of added components can only be determined after careful review of the SDS and other available hazard literature.

    Confinement and/or the addition of fuel to AN creates a real danger of explosion. The addition of heat when either of these conditions exists can lead to disaster. Accordingly, the responder should quickly assess if AN has been involved in the fire and whether the AN has been compromised in any of these ways, and plan the fire response accordingly.