Esquerra Laser SOP4 Fire Marshal - September 21, 2021 Safe Operating Procedures - Class 4

Q: What makes Class 4 lasers a higher fire hazard than Class 3B lasers?

Class 4 lasers can more easily ignite combustible materials because the directed beam can cause material to catch fire more readily.

Q: What does the Laser Use Authorization (LUA) require for Class 3B and Class 4 laser owners?

The LUA is completed by the laser owner, then approved by the Laser Safety Officer and the Non-ionizing Radiation Committee. It includes training and approved safe work practices plus a drawing of the work area and provisions for access, exposure prevention, and fire safety.

Q: What key fire safety measures are required for the Class 4 laser work area?

A suitable fire extinguisher must be present. Barriers of non-combustible materials must be installed to prevent the beam from leaving the control area, and electrical cords and equipment must match required current and amperage, while conditions like moisture and housekeeping must minimize ignition or electric shock risks.

Aug 22, 2026

Upload by Quinn Holloway

Safe operating procedures for setting up and authorizing Class 4 lasers and laser systems under SF State’s Laser Safety Program. The guide explains Class 4 fire risks, outlines required Laser Use Authorization contents, and specifies fire safety controls including suitable extinguishers, non-combustible barriers, correct electrical equipment, and housekeeping to reduce ignition and shock hazards. It also documents existing chemistry lab safeguards, chemical handling precautions, resin 3D printer ventilation requirements, and future lab authorization and review steps.

LanguageEnglish

CategoryTechnology

FormatPDF

Pages3

Reading Time8 min

AccessFree to download

Introduction

Class 4 LASERS

Laser Use Authorizations (LUAs)

Fire Safety Considerations

Chemistry Laser Lab for New Science Building

Standard Operating Precautions for the Laser Lab

Other Future Laser Labs for New Science Building

Standard/Safe Operating Procedures for Setting up a Class 4 LASER or LASER System Revision Date: September 21, 2021 Introduction At SF State, the purchase and use of Class 3B and Class 4 lasers are subject to the Laser Safety Program overseen by the Non-ionizing Radiation Committee (NIRC) and a Laser Safety Officer (LSO). The Laser Safety Program follows the guidelines in the ANSI Z136 standards. 1. Class 4 LASERS Class 4 lasers pose a higher risk of fire then the less powerful Class 3B lasers, because the directed Class 4 beam can cause combustible material to catch fire much more easily. It is important to set up the equipment and workspace in a way that addresses the increased fire hazard inherent in the use of Class 4 lasers. 1.1 Laser Use Authorizations (LUAs) The SF State Laser Safety Program requires the owner of Class 3B and Class 4 lasers to complete an application for an LUA that is then approved by the LSO and the NonIonizing Radiation Committee. Aside from training and approved safe work practices, the LUA also includes a drawing of the work area set up and provisions for access, exposure prevention and fire safety. 1.2 Fire Safety Considerations Class 4 lasers pose both direct and indirect fire hazards. The indirect fire hazards are associated with the electrical equipment and other conditions in the room. The direct fire hazards are associated with the beam itself and the risk of the beam burning a material. 1. A suitable fire extinguisher must be present on the work area. 2. Barriers made of a non-combustible material, such as metal or fire-resistant mateirals must be installed to prevent the beam from leaving the control area. 3. Electrical cords and other equipment must be suitable for the current and amperage required by the equipment. 4. Conditions such as moisture, static electricity, and general housekeeping must be such that the risk of fire or electric shock is minimized. 1.3 Chemistry Laser Lab for New Science Building The existing laser lab in Thornton Hall 810 will be moved to the new Science Building. This lab has two solid state Class 4 lasers. Each laser is used to analyze samples for chemistry research. Because of this, the fire and beam exposure hazards have already been addressed. Below is a list of precautions already in place and that are expected to continue in the new building. Standard/Safe Operating Procedures for Setting up a Class 4 LASER or LASER System Revision Date: September 21, 2021 The laser lab is used for laser experiments and other optical engineering projects—building devices and tools for research. These are mechanical and electrical engineering projects. The hazardous materials used to support these activities include the following items. None of these are in the laser path. • Small squirt bottles of reagent alcohol (less than 100 mL) and 1 small squirt bottle of ethanol (<25 mL)—for cleaning optics. • Assorted commercial hardware store items: Several cans of WD-40; machine oil and grease, spray paint, epoxies, glues, compressed air, Teflon lubricants. • 500 mL of isopropyl alcohol for cleaning prints from the resin printer The lab includes a resin 3D printer for student projects. The printer uses plastic resins and the only use requirement is a well ventilated space. It is currently in the fume hood in TH 810. The fume hood is not in view of the current laser. A ventilated space or hood is included in the new space and the resin 3D printer will be installed there. Notes: a. Currently, experiments are performed on <1mL of protein samples in water with salt. b. There are no flammable, reactive or ignitable liquids used to operate this laser. Standard Operating Precautions for the Laser Lab 1. Laser Use Authorization was approved with existing power supplies and electrical wiring. 2. The Class 4 beam is enclosed in a metal box along its path to the sample being analyzed. 3. Once set up, the beam does not have to be moved or

FAQs

What makes Class 4 lasers a higher fire hazard than Class 3B lasers?

Class 4 lasers can more easily ignite combustible materials because the directed beam can cause material to catch fire more readily.

What does the Laser Use Authorization (LUA) require for Class 3B and Class 4 laser owners?

The LUA is completed by the laser owner, then approved by the Laser Safety Officer and the Non-ionizing Radiation Committee. It includes training and approved safe work practices plus a drawing of the work area and provisions for access, exposure prevention, and fire safety.

What key fire safety measures are required for the Class 4 laser work area?

A suitable fire extinguisher must be present. Barriers of non-combustible materials must be installed to prevent the beam from leaving the control area, and electrical cords and equipment must match required current and amperage, while conditions like moisture and housekeeping must minimize ignition or electric shock risks.

Aug 22, 2026

Upload by Quinn Holloway