Laser Safety: Hazards, Risks and Control Measures

This study focuses on laser safety and the associated hazards, risks and control measures. It covers the different types of lasers, their uses and direct and indirect risks. The study also discusses control measures for direct risks, such as proper eyewear and engineering controls, and indirect risks, such as electrical hazards and laser gas air contaminates. Desklib provides study material with solved assignments, essays, dissertations and more.

Running head: OCCUPATION HEALTH AND SAFETY
Laser Safety
Name of the Student:
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Table of Contents
Introduction......................................................................................................................................2
Uses of safety lasers.........................................................................................................................2
Direct risk or hazards of lasers........................................................................................................3
Singapore NEA................................................................................................................................3
Knowledge of the practice guidelines, regulations, standards.........................................................4
Identification of the risks and the hazards.......................................................................................4
Control measures for direct risks.....................................................................................................5
Indirect risk and hazards and the control measures.........................................................................7
Conclusion.......................................................................................................................................8
References........................................................................................................................................9

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Introduction
The LASER is an acronym when expanded means Light Amplification by Stimulated
Emission of Radiation. Through the process of optical amplification, electromagnetic radiation is
emitted by Laser. The principle upon which the Laser is based is called stimulated emission of
photons. Laser characteristics are dependent on the wavelength of the laser beam. Lasers are
monochromatic, coherent, collimated. Monochromatic means the laser light consists of a single
wavelength of light rather than multiple wavelengths; in a laser beam, the wavelengths remain in
phase and the waves are in troughs and crest and remain parallel to each other (Menzel 2013).
Laser light is collimated and remains very narrow and the laser light travels in the same
direction. Due to this property, immense is produced at the place where the laser remains
concentrated. A laser consists of an optical cavity, energy source or pumping system, and a
proper lasing medium. There are different types of lasers and they are mainly classified based on
the lasing material in the lasing cavity. solid state lasers are the ones which use the crystalline
lasing material like, neodymium lasers or ruby; gas lasers are the ones that use the gas mixture
like, helium-neon and carbon dioxide (Nazemisalman, Farsadegh and Sokhansanj 2015).
Diode/semiconductor lasers that use the p-type and n-type semiconducting materials; dye/liquid
lasers are the ones that use organic dye suspended in a liquid medium. Excimer lasers are the one
that uses the mixture of fluorine and chlorine along with inert gases like xenon and krypton and
argon. Lasers are classified based on the types like- class 1, 1C, 1M, 2, 2M, 3R, 3B, 4 (Meschede
2017). This study is based on laser safety and the associated hazards, risks and control measures.
Uses of safety lasers
The products where the class 1 and 1M lasers are used are laser printers, CD players and DVD
players. The product where the class 2 and 2M is used is the barcode scanners. The class 3R

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lasers are used in products like laser pointers. The class 3B lasers are used in products like laser
light show projectors, industrial lasers and research lasers (Warwick.ac.uk 2018).
Direct risk or hazards of lasers
The class 1 and 1M are the lasers which are considered as non-hazardous. However, it is
important to note that the level if hazard increases when viewed with telescopes, binoculars,
magnifiers and other optical aids. The class 2 and 2M lasers are lasers in which the hazard
increases when viewed for longer periods of time and the level of hazard also increases when
viewed with the optical aids. The class 3R lasers are the lasers that depend on the beam area and
the power. This can be hazardous when viewed directly for a long period of time and also when
stared directly at the beam of lasers without any eye aid. However, the risk of injury can be more
when viewed along with optical aids. The class 3 B is the class of laser which has immediate
issue of skin hazard from the direct beam and also has the immediate eye hazard when the beam
is viewed directly. The Class 4 lasers are the lasers which cause the immediate skin hazard and
also has the eye hazard due to either the reflected or direct beam of light. it can also present with
a fire hazard. The class 4 lasers are found in products like laser light show projectors, industrial
projectors, research lasers, medical device lasers for the surgery of eye or skin treatment
(Fda.gov 2018).
Singapore NEA
In Singapore, lasers come under the legislation of the Radiation Protection Act and also within
the purview of its regulations. This is also administered by the National Environmental Agency
(NEA). Within the purview of this legislation, all the class 4 and the class 3b apparatus and it
also includes the laser pointers which also belong to these classes are controlled apparatus. The
owners of these laser devices are made mandatory to have the licenses so that a person can

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legally possess the device and use it as well. Any person found possessing the laser device which
belongs to the class 3b and class 4 without the proper licence that is provided by the Director-
General of Environmental Protection will be considered to be guilty. The punishment for this
offence can be imprisonment for up to 5 years or 100 thousand dollars fine (Nea.gov.sg 2018).
Knowledge of the practice guidelines, regulations, standards
Majority of the international and the national standards focus on the safety which is based on
theory and thus includes a mathematical approach. The users of the Lasers must have the
technical knowledge of how to work with the lasers and it includes the laser classification,
maximum permissible exposure, optical density levels, nominal ocular hazard area, exposure
limits. This information is not included in the medical education programs and the and at the
same time is not necessary for the healthcare professionals to perform the calculation during
operation. This information is only needed to increase the awareness of the practitioners so that
they become aware of the concepts and how they impact the procedure and policy (Castelluccio
2012).
Identification of the risks and the hazards
If the attributes of the laser are all well understood, then such hazards can be averted.
Hazard arise from the dangerous conditions, through the unanticipated exposure of the materials
and tissues to the laser energy or laser light. Direct beam hazards on the explosion of the gases,
drape fire, endotracheal tube fire, eye damage, tissue burns and also include hazards from the
non-beam hazards. The non-beam hazards include the airborne contaminants generated through a
laser (surgical plume), system failures, toxic dyes and electrical damage (Allmen and Blatter
2013).

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The risk is also identified and defined as the level of exposure that will result in injury and
identifiable hazards. Levels of risk will differ depending on each person associated with the laser
equipment and each member of the leaser team. The risk level may vary with the clinical
application of a system and it depends on the experience of both the users and operators, training,
levels of education, target tissues, power parameters, delivery device. The people that are present
in a treatment room where the class 4 or class 3b laser is used in the healthcare system, there is a
huge chance of risk exposure for the eyes. The level of eye damage from the laser will depend on
the wavelength of the laser light. For example, a laser light of wavelength 10,600 nm is capable
enough to generate heat that can cause flammability hazards. The users that are using such lasers
need to be cautious of keeping the dry objects and alcohol solutions in the vicinity of the laser.
Another example of the low-level laser operating at the wavelength of 780 nm and when
delivered from a single handheld device does not require much safety controls. There are
however hazards arising from the ocular protection (Forbes 2014).
Control measures for direct risks
Laser viewing cards- cards are used for viewing the cards that are not in the visible spectral
range. Such laser beams fall in the regions of ultraviolet or infrared regions. It is also essential
for them to have a certain way so that the profiles of the beam become visible. A low cost of
viewing such as lasers in the non-visible range is through the usage of viewing cards, which are
also called detector cards and infrared sensor cards. These tools are made up of plastic and are
almost the size of a credit card. The viewing cards have a photosensitive area which emits the
visible light when it is hit by a laser light of a particular wavelength. Some of the operation
principles upon which the principles of viewing cards are based are phosphorescence,

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upconversion fluorescence, direct generation of fluorescence, thermochromic materials (Rp-
photonics.com 2018).
Proper eyewear- usage of the proper eyewear is based on the selection of the wavelength
of the laser used, radiant exposure, visible light transmission requirements, comfort, adequate
prescription lenses and peripheral vision. It also involves the taking out of the reflective
substances like the removal of the jewellery, watches and coins. Following the standard
operating procedure when using the class 3b and class 4 lasers. Avoiding the eye level beams
and blocking the beam when inserting the new optical elements (Ehs.washington.edu 2018).
Skin protection- skin can be protected through the usage of the gloves and clothing which are
based on the maximum permissible exposure. Also, a person needs to be cautious when
operating with the viewing cards for the higher range optical spectrum (Ehs.washington.edu
2018).
Engineering controls- the major type of the engineering controls include the key control,
remote interlock, beam enclosures, protective filter installations, attenuators and barriers
(Ehs.harvard.edu 2018).
Administrative controls- the various administrative control measures include the training,
instruction and information; signage; specific and through controls; laser equipment registration
(arrangement for maintenance), laser user registration (arrangement for servicing and usage)
(Environmental Health and Safety 2018).
Engineering controls- these are the safety feature that is inbuilt within the laser
equipment supplied by the manufacturers. This laser equipment must comply with the FDA and
the IEC standards. This laser equipment comes fitted with the safety features like the beam

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attenuators, housing interlocks, emergency off control, standby control, visible and audible
emission indicators and guarded foot switch (Lawrence 2017).
Ocular hazards and the protective measures- class 4 and class 3b lasers can have the
direct and indirect impact upon the eye and can be mitigated only through wearing of the
protective eyewear (Yiu, Itty and Toth 2014).
Laser safety officer- one of the control measure is the appointment of a laser safety
officer who will deal with the management of the risk. The laser safety officer also has the
authority that ensures the compliance with the applicable rules and standards. The person should
be competent to validate the skills and the knowledge of the personnel involved along with the
assessment of all the system. The Laser safety officer can a properly qualified person, a nurse, a
physician, biomedical engineer, safety consultant, practice manager, infection control officer,
occupational safety and health officer or a risk manager. The laser safety officer will also be
responsible for the technological assessments, and also provide his advice on the purchases of
the laser equipment (Barat 2012).
Indirect risk and hazards and the control measures
Electrical hazards (shocks)- a person can get electrical shocks due to the usage of the heavy duty
industrial plugs and wires; ribbons and cables that are of flexible nature. This can be effectively
mitigated by labelling the electrical equipment and the faulty equipment are labelled and
removed from service (Ehs.princeton.edu 2018).
Fire hazard (fire or explosion)- usage of the fire retardants clothing and materials; usage
of the valid firefighting equipment; personnel trained in the firefighting and the also in the
emergency preparedness; emergency access point is kept unobstructed (Ehs.princeton.edu 2018).

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Laser Gas Air contaminates- laser plumes that contain the bacterial spores, carcinogens, fine
dust mutagen, irritants, metal oxides, viruses and cancer cells. Respiratory protection; localized
ventilation system through the high-efficiency particulate air (HEPA) filters and plume
scavenging systems (PSS) capture and neutralizes the plume (Lsdm.ucop.edu 2018).
Tripping hazard- effective cable management is the main, always maintaining proper
housekeeping all the times.
Conclusion
Form the above study it can be concluded that, laser technology has been devised from
the needs generating from the hospital operating rooms. The responsibility of the laser equipment
is not just taken up by the hospital staff and the individual users and but also by the equipment
manufacturers. There are risks that arise due to the insufficient knowledge of the practitioners
that operate on the laser systems. The risk then leads to the potential hazards and the again lead
to further health risks and organ damage. The control measures then come into play that assesses
the technical and the human practise errors. This study empathises on the laser light and the
various risks, hazards as well as the control measures.

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References
Allmen, M.V. and Blatter, A., 2013. Laser-beam interactions with materials: physical principles
and applications (Vol. 2). Springer Science & Business Media.
Barat, K.L., 2012. Laser safety in the lab. Society of Photo-Optical Instrumentation Engineers
(SPIE).
Castelluccio, D., 2012. Implementing AORN recommended practices for laser safety. AORN
journal, 95(5), pp.612-627.
Ehs.harvard.edu, 2018. [online] Ehs.harvard.edu. Available at:
https://www.ehs.harvard.edu/node/7566 [Accessed 7 May 2018].
Ehs.princeton.edu, 2018. Section 2: Laser Hazards. [online] Ehs.princeton.edu. Available at:
https://ehs.princeton.edu/book/export/html/363 [Accessed 7 May 2018].
Ehs.washington.edu, 2018. [online] Ehs.washington.edu. Available at:
https://www.ehs.washington.edu/system/files/resources/lasermanual.pdf [Accessed 7 May 2018].
Environmental Health and Safety, 2018. Control Measures by Laser Classification. [online]
Environmental Health and Safety. Available at: http://ehs.oregonstate.edu/laser/training/control-
measures-laser-classification [Accessed 7 May 2018].
Fda.gov, 2018. Laser Products and Instruments. Retrieved from https://www.fda.gov/Radiation-
EmittingProducts/RadiationEmittingProductsandProcedures/HomeBusinessandEntertainment/
LaserProductsandInstruments/default.htm
Forbes, A. ed., 2014. Laser beam propagation: generation and propagation of customized light.
CRC Press.

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Lawrence, J.R. ed., 2017. Advances in laser materials processing: technology, research and
applications. Woodhead Publishing.
Lsdm.ucop.edu, 2018. Laser Generated Air Contaminants (LGACs) | Lab Safety Design Manual.
[online] Lsdm.ucop.edu. Available at: http://lsdm.ucop.edu/sections/laser-generated-air-
contaminants-lgacs [Accessed 7 May 2018].
Menzel, R., 2013. Photonics: linear and nonlinear interactions of laser light and matter.
Springer Science & Business Media.
Meschede, D., 2017. Optics, light and lasers: the practical approach to modern aspects of
photonics and laser physics. John Wiley & Sons.
Nazemisalman, B., Farsadeghi, M. and Sokhansanj, M., 2015. Types of lasers and their
applications in pediatric dentistry. Journal of lasers in medical sciences, 6(3), p.96.
Nea.gov.sg. (2018). Lasers and Laser Pointers. Retrieved from http://www.nea.gov.sg/anti-
pollution-radiation-protection/radiation-protection/lasers-and-laser-pointers
Rp-photonics.com, 2018. Encyclopedia of Laser Physics and Technology - laser viewing cards,
infrared sensor cards, detector cards, sensitivity, mid-IR, phosphorescence, fluorescence,
upconversion, thermochromic. Retrieved from
https://www.rp-photonics.com/laser_viewing_cards.html
Warwick.ac.uk, 2018. Laser Classification. [online] Warwick.ac.uk. Available at:
https://warwick.ac.uk/services/healthsafetywellbeing/guidance/lasers/appendix1classification/
[Accessed 7 May 2018].

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Yiu, G., Itty, S. and Toth, C.A., 2014. Ocular safety of recreational lasers. JAMA ophthalmology,
132(3), pp.245-246.