Protect Employees, Contractors With Safe Work Permit System

A methodical approach ensures safety issues are considered and multiple hazards are accounted for.
By David Ayers | January 14, 2011

The manufacturing of ethanol is a pretty straightforward process that is inherently dangerous if safety procedures are not followed. Compliance with safety procedures is complicated whenever contractors and subcontractors work at the facility. Some of the potentially hazardous situations where contractors are often brought in to augment plant personnel include line breaking, entering confined spaces and working on systems where lockout/tagout procedures need to be followed. Many accidents are attributed to a lack of communication between the contractor and the plant personnel. Plant managers should always have a safety orientation meeting with contractors prior to beginning work.

Permit Areas

Ethanol plants are covered under several sections of the Occupational Safety and Health Administration’s Process Safety Management Standard found at 29CFR 1910.119. Ethanol plants will meet the OSHA threshold if they exceed 10,000 pounds of anhydrous ammonia used, or 15,000 pounds of aqueous ammonia (greater than or equal to 44 percent). There is an exemption for “hydrocarbon fuels used solely for workplace consumption as a fuel (e.g., propane used for comfort heating, gasoline for vehicle refueling), if such fuels are not part of a process containing another highly hazardous chemical by this standard.” OSHA’s Process Safety Standard specifically calls for establishing a “hot work” permit system.

OSHA’s confined space entry standard, found at 29CFR 1910.146, will also apply to ethanol plants. All confined spaces should be labeled as “Danger—Permit Required Confined Space—Do Not Enter.” Even non- permitted confined spaces will need to be labeled as “Non-permit Required.” Permit-required confined space operations include the cleaning of process vessels, railcar tankers, truck tankers and grain bins, to name a few. 

A nonpermit required confined space is large enough and configured so that an employee can bodily enter to perform assigned work. It also has limited entry and exit (other examples include silos and feed hoppers) and is not designed for continuous human occupancy. Most, if not all, confined spaces at an ethanol plant will be permit-required confined spaces that may contain a hazardous atmosphere, contains a material that has the potential for engulfing an entrant such as grain or contains any other recognized serious safety or health hazard. The internal configuration could potentially trap or asphyxiate an entrant with inwardly converging walls or a floor that slopes downward and tapers to a smaller cross-section.

Establishing a comprehensive safe work permit system starts with deciding what operations will need a permit to be completed. Some examples of common operations needing safe work permits include: 

• Hot work—welding, cutting, grinding and spark producing work,
• Line break—liquid and gaseous chemicals, water, sewer and process water,
• Confined space entry,
• Hoist and rigging, also called heavy lift,
• Working at elevated heights,
• Fire detection and suppression system impairment during maintenance, testing, or construction,
• Air and water pollution abatement system maintenance on areas such as the CO2 scrubber or bag house maintenance.

Operations Covered

A safe work permit does not mean that the job is safe and easy to complete. It simply authorizes employees or contractors to work in the hazardous conditions. The main purpose of the permit system is to ensure that all the steps have been taken to make the job as safe as possible, while coordinating the work with the plant’s operations and maintenance staffs. Multiple permits will most likely be needed, covering multiple categories of potential hazards. A safe work permit system can aid overall plant hazard abatement with the added attention to detail. Plus, personnel will no longer struggle through an undocumented and ever-changing process to get a job done.

One example of a situation needing multiple permits is during construction and retrofitting when process piping is welded to a process vessel. The welding will take place on both sides of piping entering the process vessel, so the hot work section of a safe work permit document is completed, along with the confined space section.

Another example is when the ethanol plant’s footprint is being reconfigured. Process vessels are lifted by a crane and repositioned. In this case, complete the permit section for hoist and rigging (also known as heavy lift in some companies) along with the hot work section to weld the new or reconfigured piping. If the operation involves the use of a scissor lift or cherry picker to reach the area, then also complete the section for working at elevated heights.

Another example is the addition of an ethanol storage tank and the installation of a new line to the ethanol tanker loading area. The ethanol tank will need to be checked for proper cleaning and any hazardous gases present if the tank being added to the plant is a used one. The confined space section along with the hot work section will need to be completed in the safe work permit.

In the final example, some states’ operating permits have provisions for operational fire detection and suppression systems along with air and water pollution abatement. Bag house maintenance is covered in the air and water pollution abatement section. While not required by OSHA, adding this to the “safe work permit” can help you with documentation requirements for regularly scheduled and emergency work on these systems.


Once a safe work permit system is created, employees will be trained in its purpose and use, and progress in its implementation monitored. It also helps for the employees to be involved as much as possible in writing the program so they feel as though they own the process, instead of it being a corporate mandate via e-mail from a person no one has met. The employees are also experts in detecting unsafe working conditions. Their help will make the ethanol plant as safe as possible.

For some companies, this type of procedure will be a culture change. Ethanol is a young industry and cultures take time to grow. Employees should be continually trained and checked to make sure the safe work permit system is followed and updated as needed.

Finally, each safe work permit needs to be authorized by the appropriate plant supervisor before work is started. This usually involves the signature of the shift supervisor at a minimum, if not the plant manager. Before authorizing, the permit should be reviewed to ensure that all steps have been taken to reduce the risk of accident. The employee performing the work should also sign the permit. To ensure proper coordination between plant personnel and outside contractors, the contractor’s project manager should also sign the permit stating that they know and understand the permit provisions.

Working with contractors and sub-contractors can add a level of complexity to the system. The contractor and sub-contractor must know exactly when a permit will be required every time. Getting it correct most the time is a recipe for disaster. Contractors and subcontractors should be chosen carefully—taking the lowest bid doesn’t always mean hiring the safest and most quality-conscious company. One of the best ways to ensure coordination and compliance with the safe work permit system is to cover the procedure at a pre-construction conference. Sit down and explain the expectations of the contractors and subcontractors to complete the work safely and incident- and injury-free. Even if the contractor or subcontractor tries to persuade the ethanol plant to use an alternate permit system, resist. It’s your plant and your responsibility that it operates safely. Use the safe work permit system that you have customized to your needs.

While ethanol plants are straight-forward processes, the use of contractors and subcontractors to perform specialty work or to augment plant personnel will continue. Retrofits, upgrades and maintenance are ongoing. Creating a safe work permit system is one way to make sure that all employees and contractors identify safety hazards, implement proper safety procedures and coordinate their work with others. Ethanol plants are not only costly investments, but they employ our families and friends who deserve to go home to their families every night.

Author: David Ayers,
Principal Consultant, Applied Safety Management