Hot work refers to any process that involves open flames, sparks, or heat-producing tools and equipment. The term "hot work" is commonly used in industrial and regulatory contexts, often carrying specific safety and compliance requirements governed by fire codes and occupational safety standards.
Common hot work processes involve welding, soldering, cutting, brazing and the use of powder-actuated tools or similar fire producing operations. These processes produce sparks or heat which can ignite flammable materials around the work area or flammable gases and vapors in the workspace.
The process of joining two pieces of metal or plastic together through an electrode. Several forms of welding exist, including:
Welding temperatures vary depending on the type of electrode, but is typically higher than soldering.
Soldering is the same type of joining process as welding but uses different filler material called solder and operates at under 450 degrees Celsius (841 degrees Fahrenheit). Soldering is commonly used in circuit boards and copper pipes in plumbing.
Brazing is used in applications to join close fitting members in the range of 0.001 to 0.005 inches. Brazing operations are conducted at temperatures above 450 degrees Celsius.
Cutting processes that produce sparks fall under the category of hot work. Examples include sparks produced from saw cutting and grinding.
The safety concerns associated with hot work activities can vary significantly depending on the specific processes involved and the environmental conditions of the workplace. Although nearly every hot work job is unique in some way, they typically share common fire-related hazards. To address these risks, general safe work practices can be implemented:
While hot work is inherently hazardous, using the methods listed above along with the hierarchy of controls is widely recognized as a best practice for maintaining safety during these types of activities.
Fire watch is a short-term safety work practice that involves one or more individuals continuously monitoring a building, or a specific area within it, to detect and address fire hazards during hot work operations or during periods of life safety system impairments.
During hot work activities, fire watch is intended to ensure that hot work byproducts (sparks, slag, metal, etc.) do not affect the surrounding workplace or spread to other areas. Fire watch duties must be carried out by at least two individuals. In the United States, OSHA specifies that the person performing the hot work cannot also serve as the fire watch.
Fire watch duties include:
The hot work permitting process is a safety procedure required by regulatory statutes that establishes a formal authorization before any hot work activities begin. This process serves as both a safeguard and a written declaration from the hot work operator, confirming that all necessary safety practices have been followed. It also acts as a reminder to ensure no critical steps are overlooked before starting the work.
When referring to widely recognized regulatory guidance such as National Fire Protection Agency (NFPA) 51B: Standard for Fire Prevention During Welding, Cutting, and Other Hot Work and the International Fire Code (IFC) Chapter 35: Welding and Other Hot Work, this permitting process is required to be completed before any hot work can begin.
<u>Steps in the hot work permitting process:</u>
Confined spaces present a unique challenge with hot work for several reasons. Hot work performed in storage tanks, pipelines, and sewers present a risk of explosion due to the presence of flammable gasses. Physical and chemical hazards in confined spaces are:
In the united states, OSHA requires confined spaces where hot work is done to acquire a permit for hot work. General requirements for hot work include:
There are several specific circumstances in which an employer may qualify for exemptions from parts of the regulation, such as when the hazard present is solely a hazardous atmosphere and forced ventilation is utilized.
Most countries in the world use their own rules and regulations that have different responsibilities for both the employer and employee regarding safety and risk mitigation in the workplace, while some countries lack these rules or struggle to enforce them. The International Fire Code Chapter 35 presents a general framework for countries to adopt and utilize in the building of their own safety regulations regarding hot work.