Cutting and Welding Policy

Reason for Policy

Cutting And Welding (Hot Work) Operations

Introduction

Cutting and welding operations (commonly referred to as hot work) are important in many machine shops, maintenance, and construction activities. Additionally, cutting and welding are done in our studio art department in sculpture classes.

Potential health, safety, and property hazards result from the fumes (metal vapors), gases, sparks, hot metal and radiant energy produced during hot work. Hot work equipment, which may produce high voltages or employ the use of compressed gases requires special awareness and training. The hazards associated with hot work can be safely reduced through a combination of adequate facilities, training, work practices and personal protective equipment (PPE).

The Occupational Safety and Health Administration (OSHA) prohibits cutting and welding operations unless appropriate steps are taken to minimize fire hazards. These requirements are specified in 29 CFR 1910.252 (general requirements) and 29 CFR 1910.253 (oxygen-fuel gas welding and cutting). Please see the attached codified regulations.

Scope and Application

This policy applies to all cutting and welding activities at Dartmouth College. Contractors working on behalf of the College are expected to have trained personnel, a cutting and welding program of their own. Each contractor must obtain, complete and return a Dartmouth supplied hot work permit as required by this policy.

Roles and Responsibilities

Department or Shop Supervisors/Faculty/Staff

• Ensure that only properly trained and supervised individuals conduct hot work operations.
• Develop and maintain adequate facilities.
• Ensure adequate housekeeping and fire protection.
• Complete and return hot work permits as required.

Contractors

• Provide evidence of a welding safety program to their respective project officer,
• Familiarize employees with Dartmouth College hot work permit system.
• Provide only trained workers for welding tasks.

Help with this is available from EHS.

Environmental Health and Safety

• Develop practices and procedures to help ensure welding safety.
• Periodically audit welding practices to ensure compliance and safe work practices.
• Provide fire extinguisher training to those authorized to conduct hot work activities.

General Cutting and Welding Controls

College areas where hot work is done must be designated, prepared, equipped and approved by EHS. Only trained and authorized individuals are permitted to perform hot work.

Combustible and flammable materials within the work area must be protected against fire hazards and the operation should not pose hazards to others in nearby areas. The following controls must be used:

• Hot work must be done in properly designated¹ and equipped shop areas with adequate ventilation. Special precautions must be followed whenever hot work is done outside a designated area.²
• Cutting and welding operations restricted to authorized individuals. An individual is considered to be "authorized" when they can demonstrate a requisite knowledge and skill set through a combination of training and experience. Authorized individuals are those who perform welding as a primary job responsibility for the College. This does not include students or others with only limited experience.
• Students and others with limited experience must be adequately supervised by authorized individuals.
• All combustible material(s) must be at least 35 feet from the work site. If this is not possible, combustible materials must be covered or shielded using appropriate nonflammable materials such as welding curtains and drapes, metal dividers or similar fire resistive barriers.
• Floor and wall openings within 35 feet of the work site must be covered or shielded to prevent hot sparks from entering walls or falling beneath floors.
• Consideration must be given to situations where ignition may result from conduction of heat through materials being cut.
• Adequate precautions must also be taken to prevent UV and thermal burns.

Explosive Atmospheres, Confined Spaces and Toxic Metals

Hot work must not be conducted in the presence of explosive mixtures of flammable gases, vapors, liquids, or dusts or where explosive mixtures could develop inside improperly prepared tanks, equipment or piping. If there are any questions about the safety of a particular operation, then EHS must be contacted prior to any work being done.

In confined spaces, EHS must be contacted prior to any work for inspection and evaluation. The Hanover Fire Department may also be involved in pre-planning and preparation. All other requirements of the College's Confined Space Program apply.

Special Note: No welding involving any of the following metals is to take place without the prior approval of EHS.

• Cadmium
• Fluorine
• Zinc
• Lead
• Mercury
• Beryllium

Cutting of stainless steel requires adequate local exhaust ventilation.

Fire Protection

A "fire watch" must be done during and for at least one hour after hot work operations have ended. A fire watch consists of two individuals—typically one who performs the work and one who provides the fire safety watch.

Additionally, the following steps must be taken:

• Anyone permitted to conduct hot work must have a current fire safety training record with EHS for the hands-on use of a fire extinguisher. (Training must be current to within one year.) This is required by OSHA.
• A fire extinguisher rated at not less than 2-A:20-B:C must be available in shop areas where hot work is performed.
• A fire extinguisher rated at not less than 2-A:10-B:C must be attached to all portable cutting and welding carts.
• If a building or area is equipped with a sprinkler system, then the sprinkler system must be operational when hot work is performed.
• If no smoke or fire enunciation device is present, the area must be monitored for an additional 3 hours. Monitoring requires periodic checks of the hot work area for a period of 3 additional hours beyond the fire watch.

Personal Protective Equipment (PPE)

Personal protective equipment specifically designed for hot work must be available and used at all times during cutting or welding. Please refer to the College's PPE policy for more information.

The need for appropriate respiratory protection must be discussed with EHS in advance. No welding involving the six metals listed above may be done without the permission of EHS.

Compressed Gas Cylinder Storage and Handling

Storage and handling of compressed gas cylinders are important parts of many cutting and welding operations. The following must be observed:

• Oxygen and fuel gas cylinders should be stored separately with the protective valve caps in place.
• Except when in use, oxygen and fuel gas cylinders should be stored at least 20 feet apart or separated by a noncombustible wall at least 5 feet high.
• Cylinder carts equipped with a cylinder restraint (such as a chain or strap) must be used for transporting compressed gas cylinders.
• All cylinders not in use must be upright and firmly secured in the upper one third.
• Regulators must be compatible with the cylinder and its contents. Many regulators are similar in design and construction. Check the regulator's model number and compare that with the cylinder's requirements.

Cutting and Welding Permits³

All welding and cutting operations that take place outside of a properly designed area must be documented with the use of a Cutting and Welding Permit (also called a Hot Work Permit). A copy of this permit is Attachment 1. Each year, the completed permits will be collected by EHS and kept on file for three years from date of issuance.

For College Employees

The Cutting and Welding Permits are numbered and kept in the Tool Crib. Numbered permits with the letter "A" are intended for use by College personnel only. Completed permits must be returned to the Tool Crib at the end of each shift.

For Contractors

Contractors working on behalf of the College must obtain a permit from EHS. Numbered permits with the letter "B" are intended for use by Contractors working on behalf of the College. These must be completed and returned to EHS at the end of each work day.

Training

All persons performing hot work must be properly trained. Training includes a combination of experience, on-the-job training, classroom instruction and adherence to the policy requirements outlined here. In general, each person permitted to weld on the Dartmouth campus must demonstrate knowledge, skills and abilities in the following related areas.

• Proper equipment operation.
• Safe handling and storage of welding materials.
• Safe handling and storage of compressed gasses.
• Fire safety and fire prevention.
• Requirements for a hot work permit.
• Selection and use of personal protective equipment.
• For those who may have to work in confined spaces, participation in confined space training.

Audits and Review

Periodically EHS will conduct an audit, collect hot work permits and evaluate work practices. Additional training or revisions to this policy will be made as needed.

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1. This includes floor or door signs to indicate that welding equipment is within and precautions for entry as appropriate.

2. In general terms, this refers to construction and other situations where the work cannot be easily moved. In these situations, the area must be made fire safe and all necessary precautions taken to prevent a fire or welding related accident or loss.

3. The Power Plant has its own hot work permit system based on the requirements of this program.