Laser Safety

Laser systems are used across Toronto Metropolitan University for both research and teaching applications.

TMU’s Laser Safety Program, administered by the Environmental Health and Safety (EHS) laser safety officer, is designed to protect students, faculty, staff and visitors from the hazards associated with laser radiation. An overview of the Laser Safety Program can be found in the (google doc) Laser Safety Manual (external link) .

Getting started

Applying for a permit to work with class 3B and 4 lasers

All work conducted by university members with laser systems on university premises or under the control of the university requires a laser permit for class 3B and 4 lasers.

Complete a Laser Safety Permit application.

Registration and inventory

All users are expected to register their laser systems so that the university is familiar with and aware of its inventory. To register, complete the (google form) Laser Equipment Registration and Inventory Form (external link) . Following the registration, the laser safety officer will contact you to complete a risk assessment.

Setting up your lab to work with lasers

Setting up your lab is an important process in making sure that proper controls are in place to provide for a safe working and teaching environment. All users are expected to follow the steps below when setting up a lab. If it is your first time going through this process, we encourage you to contact the laser safety officer at ehs@torontomu.ca or 416-979-5000, ext. 554212 for support.

Training

Training is a key component of the Laser Safety Program and is mandatory for all users working with lasers, especially those which are classes 3B and 4.

Training is offered at the beginning of each term every year and is open to new and existing users. To sign up for training, please contact the laser safety officer at ehs@torontomu.ca or 416-979-5000, ext. 554212.

Follow the laser lab setup guidelines.

Setting up a laser lab at TMU

Quick step-by-step guide

Use this step-by-step guide when setting up your laser lab at TMU:

Obtain laser specifications (e.g. laser class, power/energy per pulse, wavelength(s), beam diameter, beam divergence).
Obtain the manufacturer’s user manual and send a copy to the laser safety officer.
Register your laser(s) with the laser safety officer by completing the (google form) Laser Equipment Registration and Inventory Form (external link) .
Complete a Laser Safety Permit Application.
Complete training:
1. Required for laser classes 3R (previously known as 3A), 3B and 4.
2. Recommended for laser classes 1, 1M, 2 and 2M.
Set up your lab:
1. Determine and apply all necessary engineering and administrative controls.
2. Purchase appropriate personal protective equipment (follow the information below).
Arrange for a lab visit by the laser safety officer once setup is complete.

How to classify your laser

Laser class is provided by the manufacturer as is required by law. However, any in-house modifications made to a laser may change its classification (e.g. completely enclosing a laser system — where no beam is accessible at all — can bring a class 4 laser down to a class 1). Your user manual must contain this information. In addition, the laser itself must have a label on it that includes this information. The following are some examples of laser product labels:

Caution Class 4 Invisible Laser Radiation sign

Laser classification table

The laser classification table can be used as a general guide to classify laser systems. Please note that class 1 presents no hazard and class 4 presents the highest hazard.

Laser class	Description
1	Considered incapable of producing damaging radiation.
1M	Considered incapable of producing damaging radiation, unless the beam is viewed with an optical instrument (e.g. eye-loupe, telescope).
2	Emits in the visible range — eye protection is normally afforded by the natural aversion response.
2M	Same as class 2, but potentially hazardous if viewed with certain optical aids.
3R or 3A (IIIa)	Is potentially hazardous under some direct and specular reflection viewing conditions if the eye is focused and stable — small probability of actual injury.
3B (IIIb)	Hazardous under direct and specular reflection viewing conditions, but not after a diffuse reflection. Not a fire hazard.
4 (IV)	Hazardous to the eye and skin under direct, specular and diffuse reflection viewing conditions. May be a fire hazard (≥ 10 W/cm²). May also produce laser-generated air contaminants or hazardous plasma radiation.

Laser lab setup

There are many engineering and administrative controls which must be in place for class 3B and 4 lasers. The following tables provide some information on which measures are required, depending on whether the laser is class 3B or 4.

Engineering control measures table

Legend

R: Required

O: Optional

X: No requirement

NC: No further controls required

NHZ: Nominal hazard zone analysis required (performed with laser safety officer)

Engineering control measures	Laser class: 3B (IIIb)	Laser class: 4 (IV)
Protective housing Protective housing is a physical barrier preventing laser radiation in excess of the Maximum Permissible Exposure (MPE)* from exiting the laser. The aperture through which the useful beam is emitted is not part of the protective housing. The protective housing limits access to other associated radiant energy emissions and to electrical hazards associated with the components and terminals, and may enclose associated optics and a workstation. Typically, the protective housing is provided by the laser manufacturer.	R	R
Without protective housing	Laser safety officer will determine if this is necessary	Laser safety officer will determine if this is necessary
Interlocks on protective housing An interlock system on the protective housing prevents access to the laser radiation above the MPE*. It is activated when the protective housing is opened during operation and maintenance. The interlock shall not be overridden during operation.	R	R
Service access panel A service access panel is the portion of protective housing that is only intended to be removed from laser or laser system by service personnel.	R	R
Key control A key control is the key used to control the master switch, which affects beam termination and/or system shutdown.	O	R
Viewing portals (that reduce light below the MPE*) Viewing portals are windows that allow safe viewing of experiments using interlocks, filters and/or attenuators.	R	R
Collecting optics (that reduce light below the MPE*) Collecting optics include lenses, telescopes, microscopes, endoscopes and eye-loupes, and must include interlocks, filters and/or attenuators to provide safe viewing.	R	R
Enclosed beam path	NC	NC
Limited open beam path	NHZ	NHZ
Totally open beam path	NHZ	NHZ
Remote interlock connector The remote interlock connector (e.g. a “panic button”) deactivates or reduces the accessible radiation below the MPE* on entry to a protected area.	O	R
Beam stop or attenuator	O	R
Activation warning systems An activation warning system is a system of alert (e.g. an alarm, a warning light that should be visible through protective eyewear, or a verbal “countdown” command during the activation or start-up of the laser).	O	R
Emission delay	X	R
Labels	R	R
Area posting	R	R
Indoor laser-controlled area	R	R
Temporary laser-controlled area	R	R

*Maximum Permissible Exposure (MPE): This is based on specific laser parameters as described in ANSI Z136.1 (2014) standards, such as wavelength, power or energy per pulse, beam diameter, beam divergence, collecting optics, etc.

Administrative and procedural control measures

Legend

R: Required

O: Optional

X: No requirement

NC: No further controls required

NHZ: Nominal hazard zone analysis required (performed with laser safety officer)

Administrative and procedural control measures	Laser class: 3B (IIIb)	Laser class: 4 (IV)
Standard operating procedures	O	R
Output emission limitations	Laser safety officer will determine if this is necessary	Laser safety officer will determine if this is necessary
Laser worker training	R	R
Authorized personnel	R	R
Alignment procedures	R	R
Eye protection** (if MPE is exceeded)	R	R
Skin protection (if MPE is exceeded)	R	R
Spectator control	O	R
Home-built/modification of laser systems	LSO will classify	LSO will classify

**Eye protection must have appropriate optical density (OD) for specific use parameters (e.g. wavelength, power or energy per pulse, beam diameter, beam divergence, collecting optics).

Additional resources

Safety glasses

To help users select the proper safety glasses when working with high-powered lasers, use the (google doc) Eyewear Materials Technology Selection for Lasers (external link) document as a guide.

Laser hazard analysis software

To determine your MPE, OD, NHZ and NOHD, use Easy Haz (external link) , an online calculation tool.

Recommended laser and laser safety equipment suppliers

The following suppliers are recommended for laser and laser safety equipment purchases. These purchases should be made in accordance with the university’s Purchasing Procedure. For assistance, please contact Purchasing Services.

BEAMSTOP'R Laser Impenetrable Custom Drapery Systems (external link)

Kentek Corporation Laser Safety Products (external link)

Lasermet Ltd. Laser Safety Solution (external link)

Laser Safety Industries (external link)

Laser Safety Systems (external link)

Laserglow Technologies (external link)

NoIR Laser Shield (external link)

Rockwell Laser Industries (external link)

SPERIAN Eye & Face Protection (available from Honeywell (external link) )

Legislation

The Laser Safety Program is in compliance by law with the Occupational Health and Safety Act (OHSA) (external link) and the American National Standard for the Safe Use of Lasers (ANSI Z136.1 – 2014).