Health and safety – Faculty of Engineering

Health & safety

Comprehensive Health and Safety resource site for faculty, staff and students.

Employee rights

The right to know means that workers have the right to be trained, supervised, and informed about potential hazards in the workplace. As such, the employer and the joint health and safety committee have a responsibility to communicate with workers.

The right to participate means that workers have the right to identify any and all hazards in place where they work. Further, workers can recommend solutions through the joint health and safety committee.

The right to refuse work means that workers have the right to refuse work they believe could be dangerous to their health and safety, or that of another worker.

Note: Subsequent to a work refusal, the supervisor must investigate the concern and, if indeed unsafe, take all necessary steps to correct the hazard. A joint health and safety committee member has the right to take part in the investigation with the supervisor.


All persons working in Engineering Physics or CEDT facilities are required to read and abide by the following terms:

  1. Don’t work in a lab or office unless the supervisor has given you permission.
  2. Don’t work in any lab unless the lab supervisor has provided training in the safety procedures specific to the lab.
  3. Only use equipment if you’ve been trained in the safe operation of the equipment by the supervisor.
  4. You need to complete all Mandatory Training in a timely fashion. Please visit the corresponding Safety Program tab on this page.
  5. You need to familiarize yourself with the Faculty of Engineering and Faculty of Science Laboratory Manual.
  6. Do not lend your access card or keys to other people or provide access to them.

Health and safety committee

The members of the Engineering Physics / CEDT Health and Safety Committee are:

  • Dr. David Novog (Co-Chair)
  • Doris Stevanovic (Co-Chair)
  • Jon Bradley
  • Peter Jonasson
  • Jared Goguen
  • Stephen Jovanovic
  • Bertha Lok-Shu Hui

The Committee receives its authority and mandate from the Terms of Reference of the Faculty of Engineering JHSC.

The Committee is obligated to:

  • Address departmental health and safety matters
  • Conduct inspections of Engineering Physics and CEDT laboratory and office space
  • Report to the Faculty of Engineering’s Joint Health and Safety Committee
  • Faculty of Engineering – JHE Lobby
  • Eng Phys/CEDT – JHE A315
  • MBE Lab – TAB 110

The Occupational Health and Safety Act (OHSA) of Ontario legislates that a Joint Health and Safety Committee (JHSC) is required at any workplace where twenty or more workers are regularly employed [OHSA Section 9(2a)]. To comply with this legislation, McMaster University has established a Central Joint Health and Safety Committee, as well as additional JHSCs to represent individual faculties and certain other working groups (e.g. Physical Plant, Downtown Campus, etc.) within the McMaster community.

The composition of JHSCs is legislated so that at least four people must compose the committee in a workplace where more than 50 people are employed [Section 9(6b)]. Furthermore, at least half of the members of the JHSC must be workers who do not exercise managerial functions [Section 9(7)].

One primary responsibility of the JHSC is to ensure that the workplace is regularly inspected by a worker or workers designated by the non-managerial members of the JHSC [Section 9(23)]. The workplace must be inspected at least once a month [Section 9(26)], or, if monthly inspections are not practical, at least a portion of the workplace must be inspected each month such that the entire workplace is inspected at least once each year [Section 9(27)].

To meet these responsibilities, McMaster University and its JHSCs establish Departmental/Unit Health and Safety Committees which conduct workplace inspections and report to their respective JHSC. Each JHSC writes a Terms of Reference (TOR) document to define how Departmental/Unit Health and Safety Committees are structured, as well as the specific inspection and reporting responsibilities of these committees. Generally, each Departmental/Unit Health and Safety Committee must be composed of at least one managerial representative (e.g. faculty member) and at least one non-managerial employee representative. At least half of the committee members must be non-managerial members. The non-managerial committee members must be permitted to inspect the entirety of the workplace annually, though preferably monthly.

The following diagram outlines McMaster University’s internal Health and Safety Committee structure. The diagram also identifies Risk Management Manual documents and Terms of Reference documents that define the delegation of responsibilities at each level.

Safety program

McMaster’s safety program is set out in documents that constitute the University’s Risk Management Manual (RMM). The RMM programs are based on industrially-established “best practices,” and on regulatory documents like Ontario’s Occupational Health and Safety Act (OHSA) legislation which defines fundamental workplace responsibilities of employers, supervisors, and workers.

McMaster’s IRS simply defines exactly who has what responsibility, based on their role with the University, as defined in the OHSA regulations. The details of McMaster’s IRS are defined in RMM 101: McMaster University’s Risk Management System.

Prevention programs are the University’s primary tool for identifying known hazards and implementing practical methods of mitigating those hazards. Hence, programs like Standard Operating Procedures (RMM 301), Safety Audits and Inspections (RMM 302), Designated Substances Control Program (RMM 500), or Radiation Safety Program (RMM 700).

These programs each clearly define the specific responsibilities of supervisors and workers who conduct such work.

Response programs on the other hand are the University’s method of preparing for worst-case scenarios. These are the contingency plans that are a fall-back option in the event that an accident occurs despite the existence of a prevention program.

Response programs cover situations like the Fire Safety Plan (RMM 1201), Hazardous Materials Spill Response Plan (RMM 1202), and First Aid Plan (RMM 1204).


Roles within the university break down into three different categories.

he employer is required to:

  • acquaint workers and supervisors with any hazard associated with the work or workplace;
  • take every precaution reasonable in the circumstances for the protection of a worker;
  • appoint a competent supervisor;
  • prescribe and provide appropriate safety equipment, materials, and protective devices;
  • ensure that the safety equipment, etc., are maintained in good condition;
  • ensure that prescribed safety measures are implemented and respected;
  • assist the workplace health and safety committee in carrying out their duties;
  • provide appropriate training to employees.

For complete details on the duties of the employer are explicitly defined in the OHSA, Sections 25 and 26.

This is an extensive undertaking. Responsibilities are therefore downloaded to supervisors and workers

In Engineering Physics and the CEDT, Supervisors would include:

  • Faculty with Laboratory Research
  • Retired Faculty with Laboratory Research
  • Facility Directors/Managers
  • Laboratory Staff with Supervisory/Training Responsibilities

Note, supervisors are also considered workers within the University. Worker responsibilities also apply, explicitly defined in the University’s Risk Management Manual.

Supervisors must complete the following documentation:

  • Job Hazard Analysis (completed with Departmental Chair and filed with department office and EOHSS)
  • Lab Assessment Form (for each lab facility)
  • Standard Operating Procedures (store copies in lab and office)
  • MSDS Inventory
  • Inspections of Facilities (required by RMM 302)

Requirements for training students, employees, visitors* and volunteers

  • Completion of JHA
  • Hazard Assessment Form
  • Mandatory Training
  • Site-specific Mandatory Training

According to OHSA, Section 1(1) Supervisor means “a person who has charge of a workplace or authority over a worker.” According to Section 27, Supervisors need to:

  • advise workers of the existence of any workplace hazards;
  • provide the worker written instructions explaining protective measures associated with workplace hazards;
  • “take every precaution reasonable in the circumstances for the protection of a worker.”

in Engineering Physics and the CEDT, workers would include:

  • Laboratory Supervisors
  • TAs
  • Post Docs
  • Research Engineers/Technical Staff
  • Research Associates/Fellow
  • Grad Students (not technically employees, but applies nonetheless)
  • Summer Student Researchers

Workers must complete the following documentation:

  • Job Hazard Analysis (completed with Supervisor)
  • Hazard Awareness Report (completed annually for each student and reviewed and signed off by Supervisor)

Training requirements

  • Mandatory Training
  • Site-specific Training

According to OHSA, Section 1(1), a worker means “a person who performs work or supplies services for monetary compensation.” The duties of a worker are explicitly defined in the OHSA, Section 28:

  • work in compliance with all prescribed workplace health and safety directives;
  • use protective equipment and devices, as prescribed;
  • report to the supervisor any safety-related equipment defects;
  • report to the supervisor any workplace hazard.


Site-specific training is an integral part of the Engineering Physics and CEDT research. As covered in our Safe Workplace Policy, all persons working with Engineering Physics or CEDT equipment must be trained in the safe operation of the equipment and made aware of Standard Operating Procedures applicable to their work by the supervisor responsible for the equipment.

CEDT equipment training

If you require training on an item of CEDT equipment that is not listed here, please contact Doris Stevanovic to make arrangements.

CEDT Clearn Room (JHE A306)AllDoris Stevanovic
CEDT Growth Lab (TAB 110)Analysis
Shahram Tavakoli
Sputtering Machine
Doris Stevanovic
Shahram Tavakoli
JHE A302Fume hoodDoris Stevanovic
Metallization (CR)
RIE (III-V materials)
alpha step
wet bench
JHE A306Doris Stevanovic
RTAJHE A314Doris Stevanovic
Hall EffectTAB 110/AShahram Tavakoli
X-ray diffractionTAB 110/AShahram Tavakoli
Photoluminescence (PL)
JHE 318Shahram Tavakoli
FTIR spectroscopyTAB 110Shahram Tavakoli
EllipsometryJHE 318Shahram Tavakoli
LIV characterizationJHE 318Shahram Tavakoli
RTAs / tube furnacesTAB 205Shahram Tavakoli
RIE (Si-based materials)TAB 110Shahram Tavakoli
Dicing sawTAB 205Dr. Chang-qing Xu
SEMTAB 205Shahram Tavakoli
Fume hoodJHE A305Doris Stevanovic

Hazard awareness

HF burns…

Hydrofluoric acid (HF) is extremely hazardous. Unlike most other acids, HF can penetrate quickly deep into tissue and bones. It reacts with calcium ions in the body, causing electrolytic damage and severe, deep pain despite minimal surface damage. Exposures to as little as 2% of the body have been reported to cause death.

Protective equipment is your best defence when working with HF.

If exposed…

  • immediately flush exposed skin with water
  • remove contaminated clothing
  • liberally apply calcium gluconate gel to the area
  • tell your supervisor and get immediate emergency medical treatment

Chemical hazards fall largely under the umbrella of McMaster University’s Hazardous Materials Management Program, as outlined in RMM #501.

Hazardous chemicals, as defined in the Laboratory Safety Handbook can be:

  • explosive
  • flammable/combustible
  • reactive
  • oxidizing
  • toxic
  • corrosive (ph < 5.5 or > 9.5)
  • compressed gas

In Canada, anyone working with hazardous materials is required to take Workplace Hazardous Materials Information System (WHMIS) training. WHMIS is considered mandatory training for all persons working in Eng Phys or the CEDT.

All chemicals must be properly labelled in accordance with WHMIS standards. A catalogue of Material Safety Data Sheets (MSDSs) must be maintained for any location where chemicals are stored.

Explosive materials

Explosive materials produce almost instantaneous release of pressure, gas, and heat when subjected to sufficient shock, pressure, or temperature.


This class of materials ignites and burns readily.

Flammables have a flashpoint below 37.8 celsius. Combustibles have a flashpoint at or between 37.8 C and 93.3 C. The flashpoint is the temperature at which the material produces enough vapour to allow ignition and burning.

At high enough temperatures certain flammable or combustible materials can spontaneously auto ignite. No flame or similar ignition source is required.

Reactive materials

This class of materials tends to react when mixed with certain other materials, potentially generating or absorbing heat, and creating chemical bi-products.

Proper storage of reactive materials and waste products with only compatible materials is critical, as the presence of incompatible chemicals could result in harmful bi-products, heat, fire, or explosion.

Oxidizing materials

Oxidizing materials can cause or promote combustion of other materials. Oxidizers can be materials rich in oxygen, like chlorates and permanganates, or materials that promote oxidation, like chlorine or bromine, by incorporating excess electrons from the oxidation process.

The presence of oxidizing liquids or solids increases risk of ignition and explosion. Certain materials that are normally non-flammable may burn in the presence of oxidizers.

Toxic materials

Toxic materials react harmfully with organic tissue. If exposed to sufficient doses, tissue damage may be irreparable. Routes of entry for toxic materials may be through the skin, or via ingestion or inhalation.

Corrosive materials

Corrosive materials, typically acids or bases, chemically attack and damage other materials that they contact. Corrosives can damage organic tissue on contact. Stronger corrosives attack tissue more rapidly. Ingestion or inhalation of corrosives or their vapours can burn sensitive digestive or respiratory tissues.

Compressed gases

Compressed gases are stored under pressure in cylinders, or sometimes in pressurized transport lines. They can be categorized as liquefied, non-liquefied, or dissolved.

The high pressures associated with compressed gases pose a hazard in the event that a tank leaks or ruptures, as the pressure can be sufficient to propel the tank at high velocity. As such, gas cylinders need to be securely attached to wall-mounted or table-mounted brackets. Cylinders must be capped and secured in a transport cart when relocated.

Compressed gases often pose additional hazards insofar as they may be reactive, flammable, oxidizing, or corrosive when released. Safety measures specific to the particular hazard should be put in place.

1. The Canadian Centre for Occupational Health and Safety,, October 18, 2005.
2. WHMIS Pocket Dictionary, J. Mayo and D.B. Morris, Genium Group, 2004. Available from EOHSS.

McMaster University’s Radiation Safety Program is outlined in RMM 700.

The University delegates the authority and responsibility for ensuring compliance with radiation safety legislation to Health Physics (HP) and the Health Physics Advisory Committee (HPAC). The HPAC is also responsible for the administration of McMaster University’s radiation safety program. In fulfilling this responsibility, Health Physics publishes a Radiation Safety Manual specific to safety considerations critical in dealing with the ionizing radiation associated with radioisotopes and X-rays. Health Physics can be contacted at x24226.

Radiation can be characterized as either ionizing or non-ionizing. The risk posed by various forms of radiation stems from their tendency to deposit energy into the materials they encounter.

Ionizing radiation is sufficiently energetic that it has the potential to knock electrons from atoms or molecules. It includes alpha and beta particles, as well as gamma, X-ray, and UV photons. In living tissue, interaction with ionizing radiation can produce damaging structural changes. Subjected to a sufficient dose, whole organs can cease to function altogether.

Table 1, modified from the Health Physics Radiation Safety Manual, illustrates permissible ionizing radiation exposure levels for the general public according to Ontario guidelines.

Dose LocationPermissible Annual Exposure (General Public)
milliSieverts (mSv) per yearrem (= 0.1 mSv) per year
Lens of the eye151.5
Any single organ505
Hands and feet505

Table 2, also from the Radiation Safety Manual, indicates the biological effects of various doses of ionizing radiation.

Dose (mSv)Effect
0 to 250No detectable effects.
250 to 1000Slight blood changes with no recovery within a few months. Delayed effects possible, but very serious effects are very improbable.
1000 to 2000Nausea and fatigue. Blood changes with delayed recovery.
2000 to 3000Nausea and vomiting on first day. Latent period up to a few weeks, then malaise, sore throat, diarrhea. Recovery likely within 3 months for healthy individuals.
3000 to 6000Nausea and vomiting within a few hours. Latent period up to 1 week, then malaise, fever, hemorrhage, loss of weight, sore throat. Death to about 50% of individuals receiving about 3500 mGy.
6000+Symptoms similar to above, but probable death for 100%.

In any case of known or suspected exposure to ionizing radiation, report immediately to your supervisor and Health Physics (x24226).

Radioactive isotopes

Nuclear materials are controlled federally by the Canadian Nuclear Safety Commission (CNSC).

Radioisotopes represent a risk due to the biological dose effects mentioned above. The hazard is exacerbated by contamination risks associated with radioisotope storage, handling, and disposal.

All personnel working with radioactive materials are required to attend training provided by Health Physics. All laboratories in which radioactive materials are to be stored must possess a valid permit, obtained through Health Physics subject to assessment of the laboratory. Warning signs must be posted.

No food or drink is permitted in laboratories housing radioactive materials.

Additional regulations apply to pregnant women who work in laboratories housing radioactive materials.

X-ray radiation

X-ray radiation safety in Ontario is legislated under Regulation 861. McMaster University’s X-ray radiation safety program is outlined in RMM 701.

Access to McMaster University X-ray facilities is limited to authorized personnel who have completed the X-ray Safety Training course provided by Health Physics.

The CEDT operates two X-ray systems. The two systems incorporate interlocked shielding mechanisms and fail-safe safety indicators so that operator exposure is effectively impossible. In meeting provincial regulatory requirements, each system was surveyed by Health Physics for safety when initially commissioned. Additional quarterly inspections are conducted by supervisory CEDT staff to ensure all safety mechanisms continue to function properly.

Non-ionizing electromagnetic radiation

McMaster University’s non-ionizing radiation safety program is outlined in RMM 702.

Non-ionizing electromagnetic radiation is of insufficient energy to cause atomic or molecular damage directly, however, the heat generated by exposure to intense non-ionizing radiation can be sufficient to induce tissue damage. The category includes visible and infrared light, as well as microwaves and radio-waves.

Most sources of electromagnetic radiation decay rapidly with distance from the source. It is possible to shield electromagnetic radiation by surrounding the source with a grounded conductive shield or mesh, where any openings in the shield must be less than one-quarter of the radiation wavelength.

Particular caution should be paid to microwave and radiofrequency generators common in plasma generation systems. These sources can create fields with high power and specific directionality. Shielding is critical, as the radiation can damage tissues.

1. McMaster University Risk Management Manual #700, October, 2005.
2. McMaster University Health Physics Radiation Safety Manual, October, 2005.
3. McMaster University Health Physics “X-ray Safety Training for X-ray Users,” Course Manual, October, 2005.

OHSS has recently established a university Laser Safety Committee, headed by a Laser Safety Officer (LSO). The committee is working to update McMaster’s Risk Management Manual Program #703 which outlines the university’s laser safety policy. As well, the committee is developing a Laser Safety Guideline outlining best practices for using Class 3b and Class 4 lasers. Look for these new documents in coming months.

In the meantime, EOHSS is offering a Laser Safety Training course. The course identifies various hazards associated with Class 3b and Class 4 lasers.

Please expect the information and guidelines contained in the body of this page to be updated to reflect McMaster’s laser safety policy as the policy is implemented.

Laser Safety

UPDATE: Engineering Physics recently acquired copies of the ANSI Laser Safety Standard Z136.1-2007. Copies can be signed out for loan from the department office.

The CEDT and Engineering Physics use lasers in a variety of applications, including photoluminescence, ellipsometry, grating fabrication, bench-top photonics experiments, and thin film stress analysis.

McMaster University’s laser safety program is documented in Risk Management Manual program RMM 703.

Potential Hazards

The most significant laser risk stems from the absorption of laser radiation in tissue. If tissue is unable to effectively dissipate the resultant heat it can be burned and permanently damaged. Naturally, the eye is most susceptible to this type of damage since it can focus light onto the retina, increasing the intensity significantly. Retinal burning can occur essentially instantaneously and may even be accompanied by explosive localized gaseous emission.

A less serious, though still considerable, risk associated with lasers is that of photochemical reaction stimulated by short-wavelength radiation.

Additional risks in laser operation include electrical shock, burns, generation of toxic air pollutants, and fire, among others.

Hazard Classification

The American National Standards Institute (ANSI) established the widely accepted the ANSI Z136.1 standard for laser safety in 1976.* The standard identified maximum permissible exposure (MPE) limits that are considered safe for laser operators.

ANSI Z136.1 also established a classification system that groups lasers into four classes depending on the power of the laser and the wavelength of emitted light. Table 1 summarizes the ANSI z136.1 class system. (For pulsed lasers, please refer to Mallow and Chabot [1978], or Sliney and Worbarsht [1980]).

Table 1: Summary of ANSI Z136.1 laser classification.
ClassGeneral DescriptionPower
Class 1Not capable of emitting hazardous radiation under normal operating conditions. Exempt from controls.See Mallow and Chabot [1978], Table 7-1A, p. 95.
Class 2Visible class 2 lasers are not capable of retinal damage under normal conditions, however could cause damage if stared at for a long time.See Mallow and Chabot [1978], Table 7-1B, p. 95.
Class 3aVisible (400 to 700nm) lasers that are incapable of damaging the eye due to natural brightness aversion, unless viewed with magnifying instrumentation or stared at for a long time.See Mallow and Chabot [1978], Table 7-1C, p. 96.
Class 3bLasers not covered by classes 1 to 3a that are sufficiently powerful to cause damage if specularly reflected or viewed directly.Visible CW lasers (400nm to 700nm) greater than 5mW and less than 500mW.
Non-visible CW lasers greater than 5mW and also less than 5mW but greater than class 2.
Class 4Produce hazardous direct beam or specular reflection viewing. Diffuse reflections may also be hazardous. Class 4 lasers can also pose a fire risk and skin burn hazard.CW lasers greater than 500mW.

*The Z136.1 standard was originally released in 1973, but was revised in 1976. A class 5 designation was dropped, and class 1 emission limits were changed [Sliney, 1980]. McMaster is currently implementing the standards outlined in the most recent revision, ANSI Z136 2007.

Laser Safety and Maximum Permissible Exposure

Any laser experiment should incorporate engineering protocols to ensure the safety of laser operators. That is, wherever possible laser beams should be enclosed to prevent accidental exposure. This is the most effective protective measure available when using class 3b or class 4 lasers.

Unfortunately, many experimental arrangements require direct operator interaction, particularly in the alignment of laser beams. Obviously, in this situation protective enclosures become ineffective and therefore “personal protective measures” become absolutely critical. A laser operator working with class 3b or 4 lasers (or some class 3a lasers when optical instruments may increase beam intensity) must use protective eyewear. The eyewear must be suitable to reduce the intensity of a beam below the MPE for the type of laser radiation in question.

Determining the MPE for a specific laser is non-trivial. Relevant factors include pupil size, wavelength, exposure duration, size of irradiated area (intrabeam or extended source viewing), incident irradiance, and continuous or pulsed laser output.

Essentially, the MPE determines the minimum attenuating strength required for eye protection to be considered safe. That is, eye protection must be chosen based on the MPE for a given laser such that an accidental exposure is rendered eye-safe, similar to that of a class 3a or lesser laser. Optical density (OD) quantifies the ability of a filter to attenuate a particular wavelength according to the formula,

OD = log_10 [Io/I]

where Io is the irradiance [W/cm^2] of the incident beam and I is the irradiance of the transmitted beam.

For example, a frequency doubled Nd:YAG laser emitting 300mW at 532nm that is attenuated by a OD 6 filter will transmit 0.0003mW. Attenuated by an OD 1.5 filter, the same laser will still transmit 9.5mW.

Please note that OD is wavelength-specific. Since many lasers emit at more than one wavelength, the OD of a filter or set of filters must take into consideration each wavelength present in the beam.

Though rigorous calculations of MPE can be worthwhile, a number of sources present a simplified guide to selecting laser eye protection, as originally developed by the U.S. Army Environmental Hygiene Agency.

Table 2: Simplified Method for Selecting Laser Eye Protection for Intrabeam Viewing for Wavelengths Between 200 and 1400 nm (from Mallow and Chabot [1978], p. 252).
Q-Switched Lasers
(1 ns to 0.1 ms)
Non-Q-Switched Lasers
(0.4 ms to 10 ms)
Continuous Lasers
(0.25 s to 10 s)
Continuous Lasers
Long-Term Staring
Greater than 3 hr
Maximum Output Energy (J)Maximum Beam Radiant Exposure (^-2)Maximum Laser Output Energy (J)Maximum Beam Radiant Exposure (^-2)Maximum Power Output (W)Maximum Beam Irradiance (^-2)Maximum Power Output (W)Maximum Beam Irradiance (^-2)Attenuation FactorO.D.
Source: “Laser Protective Eyewear,” U.S. Army Environmental Hygiene Agency, Aberdeen Proving Ground, Maryland, 1975.
Note: NR = not recommended

Choosing Protective Eyewear

To choose protective eyewear suitable for use with a particular continuous wave (CW) laser where there exists risk of momentary eye exposure:

  1. Determine the wavelength or wavelengths of the laser (usually labelled on commercial lasers).
  2. Determine the power (W) or irradiance (^-2) for the laser (usually labelled on commercial lasers).
  3. Locate the corresponding power or irradiance range in columns 5 or 6 of Table 2.
  4. Identify the corresponding optical density listed in column 10 of Table 2.
  5. Obtain appropriate protective eyewear.

Again, please note that some lasers may emit radiation at more than one wavelength. Glasses suitable for a laser’s primary wavelength may offer no protection at another wavelength, though the power emitted at the secondary wavelength may still be sufficient to damage the eye. All wavelengths must be considered and appropriate eyewear procured.

Laser Hazards (2005 draft)

McMaster University’s laser safety program is outlined in RMM #703.

Lasers emit electromagnetic radiation. Laser sources cover a range of wavelengths, encompassing ultraviolet (UV), visible, and infrared (IR) portions of the spectrum.

There are a variety of hazards associated with laser radiation. Generally, these hazards are divided into beam-related and non-beam-related categories.

Beam-related laser hazards

Beam-related laser hazards are due to

  • beam energy, or
  • photon energy.

Whereas the intensity of light emitted from most sources diminishes with distance from the source, lasers can produce extremely well-focussed beams with very little divergence. This poses a risk because even low power lasers, when focussed with the aid of lenses or the eye, can create sufficient energy density to cause rapid burning. Particularly dangerous are visible lasers, since the cornea and lens transmit in this region, putting the retina at risk of incurring burns.

Photon energy of lasers in the UV and blue portion of the electromagnetic spectrum can be of sufficient energy to induce photochemical ionization. Photochemical reactions due to light in this spectral region are, of course, linked to increased risk of skin cancer.

Laser classification takes these risks into consideration. Lasers rated Class IIIa and lower generally will not cause eye damage. See the laser classification table below for details.

Non-beam-related laser hazards

Non-beam-related laser hazards are diverse. They can include:

  • electrical hazards associated with laser pumping mechanisms
  • chemical hazards associated with materials used as the lasing medium or plume material ablated from targets


Lasers are classified according to their potential to cause damage. Classification in Ontario follows the rating criteria established by the American National Standards Institute (ANSI) in standard Z136.1.

Power (mW)NotesExamples
Class I400-700< 0.0004power too low to cause eye damage, however, may be classified higher if enclosure is removedlaser printers,
CD-ROM drives
Class II400-7000.0004 to 1unable to cause damage in blink reflex period (0.25 s)cw HeNe < 1 mW
Class IIIa400-7001 to 5not usually harmful if viewed momentarily
Class IIIb400-7005 to 500hazardous if viewed directlycommon cw HeNe lasers,
Ar ion lasers
Class IVall> 500even diffuse reflections can be hazardousmachining systems,
femtosecond systems,
all pulsed lasers between 400 and 1400 nm

Manufacturers are obligated to classify their lasers. Similarly, lasers fabricated by Engineering Physics or CEDT personnel should be labelled to indicate their classification.

1. Princeton University Environmental Health and Safety,, October, 2005.

Risks associated with electricity are primarily due to potential electrical shock and fire hazards.

McMaster University’s Electrical Safety Program is outlined in RMM #316.

Ontario Regulation 164/99 (O. Reg. 164/99) legislates that, provincially, electrical equipment and systems must conform to the guidelines established by the Electrical Safety Code. According to O. Reg. 164/99, the Electrical Safety Code is defined by the document C22.1-1998, as developed and released by the Canadian Standards Association (CSA), and subject to amendments issued by the Electrical Safety Authority (ESA). Implementation of the Code in Ontario is administered by the ESA. The ESA can also be contacted to arrange inspections of electrical equipment for purposes of approval.

According to the ESA’s Electrical Safety Code,

  • all electrical products must be labelled with approved safety markings, notably the Canadian Standards Association (CSA) stamp.

Electrical shock hazards

Severity of electrical shock depends on the amount of current generated, which can heat and burn organic tissue and can disrupt natural nervous system function, potentially causing fatal heart fibrillation. The magnitude of the current in a shock situation depends on the voltage that causes the shock as well as electrical resistance of the item subjected to the shock.

Both alternating current (AC) and direct current (DC) shocks can cause muscles to tense, making it difficult or impossible to move away from the source of the shock. Current as low as 8 mA is sufficient.

Sustained currents of 100 to 300 mA can be sufficient to cause death.

Electrical fire hazards

As in the case of electrical shock, electrical fire hazard stems from the heat generated when current flows through a conductive material.

Circuit components and wiring must be rated to sustain currents greater than those which cause circuit fuses to melt or breakers to trip.

1. O. Reg. 164/99,, October 31, 2005.
2. Electrical Hazards Course Participant’s Manual, Version 2, Worker’s Health and Safety Centre, 2002.

Protective equipment

Eye protection should be worn whenever the risk of flying debris or chemical spray exists.

Wearing contact lenses is not permitted when working with hazardous chemicals or in machining environments.

Laboratory gloves are used to protect against exposure to hazardous materials. Common glove materials include natural rubber (latex), as well as synthetic variants on rubber such as nitrile or neoprene.

Rate of reactivity dictates how long a glove is able to maintain its integrity when exposed to a chemical. Breakthrough times, the time required for a particular chemical to cause the glove material to break down, varies dramatically depending on the glove material. Please note that breakthrough times can also vary between different brands or models of gloves, often due to differences in manufacturing techniques or slight material variation.

Click here to view a guideline table of Chemical Protective Clothing Index Ratings for glove materials.

If transferring gloves from their original packaging to a new container, it is good practice to indicate glove-type on the new container. This should help prevent confusion regarding glove resistance.

Lab coats should be worn to prevent contamination of clothing. Do not take lab coats home for laundering. Home laundering creates a risk that other clothes also become contaminated.

Unless heavily contaminated, lab coats can be washed in laboratory sinks.

McMaster University’s Hearing Safety Program is outlined in RMM #403. Ontario Regulation (O. Reg.) 851 restricts unprotected occupational noise exposure to levels below 90 bBA.

Exposure to noise levels of 85 dBA is limited to a maximum of 8 hours daily.

Earplugs or muffs can be used to reduce noise levels to acceptable levels.

Laboratory safety equipment

Fumehoods use a negative pressure differential to draw air, vapours, and contaminants out of a laboratory environment.

Most experiments involving hazardous chemicals should be performed in a fumehood.

Fumehoods are to be inspected annually by University authorities to ensure airflow is adequate. Units are also often equipped with sensors to ensure that airflow is satisfactory. A sash is used to restrict the fumehood opening, maintaining an adequate pressure differential, as well as protecting workers from splashes and vapour.

Chemicals with low flashpoints should be kept in fumehoods or ventilated storage areas to minimize build-up of vapours.

Chemical showers and eye-wash stations exist to allow workers to rapidly dilute chemicals in the event of a spill or splash on the body or clothing.

In the event of exposure to chemicals requiring emergency use of a shower, clothing should be removed before showering if there is little risk of further skin exposure. Otherwise, clothing should be removed while showering. The supervisor must be notified immediately of the incident. If necessary, emergency service should be sought by dialling 88 on any university phone.

Eye-wash stations should be used in the event that chemicals splash into the eye. Dilute the chemicals by washing the eyes for at least 15 minutes, and seek emergency treatment if necessary. The supervisor must, again, be notified immediately to assist and subsequently file an incident report.

Fire extinguishers are located in or immediately outside of every laboratory or office space.

Extinguishers should be used on small fires, however, if the fire becomes out of control, immediately vacate the area of the fire and pull a fire alarm to alert emergency services. Most extinguishers contain only about 5 to 10 seconds worth of propellant.

Fire extinguishers that have been discharged even briefly must be replaced. This is because the powders used in the extinguisher tend to contaminate the release valve’s internal seal such that the propellant will slowly discharge, rendering the extinguisher useless. Contact EOHSS for assistance.

Fire extinguishers are inspected monthly by University authorities and replaced whenever necessary.

General laboratory safety

According to OHSA, critical injury is an injury of a serious nature that:

  1. places life in jeopardy,
  2. produces unconsciousness,
  3. results in substantial blood loss,
  4. involves the fracture of a leg, arm, or foot but not a finger or toe,
  5. involves the amputation of a leg, arm, hand or foot but not a finger or toe,
  6. consists of burns to a major portion of the body, or
  7. causes the loss of sight in an eye

In the event of a critical injury,

At McMaster, the EOHSS department is delegated the responsibility of ensuring that all legally binding reporting requirements are fulfilled. The scene of the critical injury is then subject to an investigation, inspected by an MOL inspector, as well as by a worker representative from the JHSC.

In the event of a critical injury at McMaster, Worker must

  • provide immediate emergency assistance
  • notify the workplace supervisor
  • ensure the scene remains undisturbed until investigated by a Ministry inspector

Supervisor then:

  • immediately notifies EOHSS
  • ensures the scene remains undisturbed until investigated by a Ministry inspector
  • completes an incident report

EOHSS then:

  • immediately notifies the Ontario Ministry of Labour (MOL)
  • immediately notifies the Joint Health and Safety Committee (JHSC) and employee’s union
  • issues a written report to the MOL within 48 hours.

In the event of an emergency, dialling 88 on any university phone* will connect to Security Services. Security Services will then immediately dispatch appropriate emergency personnel (security, ambulance, fire, or police) to the location.

* Except in the hospital, where the emergency number is 5555.

What if I dial 911?

No problem. Security Services intercepts 911 calls.

Intercepting 911 calls in this manner makes it easier to guide emergency personnel directly to the location of the emergency.

What if it isn’t an emergency?

The 88 emergency number should not be abused. If you need to contact Security Services for a non-emergency related reason, dial extension 24281.

For example, just as you would not dial 911 for something as trivial as locking your keys in your car, it would be inappropriate to dial 88 just because you locked your keys in your campus office or lab. The appropriate, non-emergency extension to call would be 24281, and a security representative would respond to help you back into your work area as soon as they can be available.

As per the terms of Regulation 1101, First Aid stations must be situated throughout the workplace at regular intervals so that injured persons can access treatment within 4 minutes. The stations must be staffed by an employee certified in Standard First Aid.

The First Aid Provider must complete an incident report in the case of any incident that requires first aid.

In the event of a serious injury, alert the local first aid provider and also dial 88 for emergency assistance.

Eng Phys / CEDT First Aid Locations

As of March 2008, First Aid stations will be situated throughout buildings across campus.

In Engineering Physics, Peter Jonasson will provide first aid. He will maintain a stocked first aid kit in JHE A304.

In TAB, Jack Wojcik will maintain a stocked first aid kit in TAB 110.

Emergency First Response Team (EFRT)

In cases of serious injury or accidents, McMaster University’s Emergency First Response Team (EFRT) can provide advanced emergency first aid.

The EFRT team is staffed by trained, certified student volunteers. The team responds to incidents across campus.

To access EFRT assistance, dial 88 and Security Services will dispatch EFRT to your location.

Ambulance Assistance

To call for emergency ambulance assistance on the McMaster campus, dial 88 from any campus phone. Security Services will dispatch McMaster’s Emergency First Response Team and an ambulance to your location.

Dialling 911 will also connect directly to Security Services so that they can ensure emergency response vehicles are directed to the correct location.

According to the Laboratory Safety Handbook, eating and drinking are allowed only “in designated clean areas away from hazardous materials and radioactive sources.”

Storage of food and drink is not permitted in laboratory refrigerators.

cMaster’s Hazardous Waste Management Program is outlined in RMM 502.

The LSH defines hazardous chemical waste as:

  • explosive
  • flammable/combustible
  • reactive
  • oxidizing
  • toxic
  • corrosive (ph < 5.5 or > 9.5)
  • compressed gas

In accordance with LSH guidelines, to dispose of hazardous chemical waste:

  • procure an appropriate waste container
  • do not fill the waste container above 3/4 of its volume
  • do not mix incompatible chemicals (click here for a partial list of compatible and incompatible chemicals)
  • keep halogenated (fluorine-, chlorine-, bromine-, or iodine-containing chemicals) separate from non-halogenated chemicals
  • apply a “waste label” to the container, and ensure that the label is properly completed and signed

Waste containers are marked with a yellow waste label, which is filled out to identify the materials contained within and the researcher responsible for the container.

When containers are ready for disposal, a list is submitted to EOHSS by the end of each Friday. The following Tuesday the waste containers are picked up by a professional waste management company. There is no need for researchers to transport their waste outside of their laboratory.

McMaster’s Laboratory Safety Handbook (LSH) thoroughly outlines waste disposal guidelines that are in accordance with federal, provincial, and regional regulations.

Disposing of empty chemical bottles…

If the content is water-soluble:

  • rinse empty bottle and allow to dry
  • deface label
  • place the uncapped bottle in the hall for custodial pick-up

If the content is a solvent or toxic:

  • leave empty bottle in fumehood until any liquid residue evaporates
  • deface label
  • place the uncapped bottle in the hall for custodial pick-up

Designated substances are materials that, due to risks associated with exposure, handling, or storage, are strictly regulated by the Ministry of Labour (MOL).

Research groups working with designated substances are legally bound to complete a safety assessment outlining compliance with applicable MOL regulations (see RMM 500).

The materials that have been rated as designated substances are:

  • acrylonitrile
  • arsenic
  • asbestos
  • benzene
  • coke oven emissions
  • ethylene oxide
  • isocyanates
  • lead
  • mercury
  • silica
  • vinyl chloride

Download a Designated Substance Assessment Form under the Forms tab.

  • Designated substance assessment form

    Designated substances are materials that, due to risks associated with exposure, handling, or storage, are strictly regulated by the Ministry of Labour (MOL). Research groups working with designated substances are legally bound to complete a safety assessment outlining compliance with applicable MOL regulations. The materials that have been rated as designated substances are: acrylonitrile, arsenic, asbestos, benzene, coke oven emissions, ethylene oxide, isocyanates, lead, mercury, silica, vinyl chloride
  • Lab door safety and contact info – CEDT

  • Lab door safety and contact info – EngPhys

  • Joint Health and Safety Committee Inspections

  • Joint Health and Safety Committee Inspections

  • Joint Health and Safety Committee Inspections

  • Supervisor safety inspections

  • Supervisor safety inspections

  • Supervisor safety inspections