Laser Safety Plan

Reason for Policy

Adelphi University maintains a laser safety program to assist researchers with the safe use of lasers in compliance with federal, state, and local regulations. The Laser Safety Program and its procedures are based on the American National Standard Institute (ANSI) Z136.1 – 2014 Standard for Safe Use of Lasers, OSHA 29 CFR 1910.97 Non-Ionizing Radiation, and 29 CFR 1910.132 General Requirements.

Who Is Governed by this Policy

Faculty, Staff, and Students

Policy

The Laser Safety Committee is the overall coordinating body that reviews the policies and procedures for the use of lasers on campus. The Laser Safety Committee is a part of the Radiation Safety committee with a combined focus on both radiation and laser safety operations at the University.

Definitions

Laser: is a device that produces an intense, coherent, directional beam of light. LASER is an acronym for Light Amplification by Stimulated Emission of Radiation. Even though ‘radiation’ is often referred to the nuclear radiation such as alpha, beta, and gamma rays, this report addresses electromagnetic radiation only and not nuclear radiation.

Laser beams are monochromatic, extremely directional, have a small angular divergence of the beam, and are coherent. Even though the laser beam is electromagnetic radiation, they can cause severe harm to the tissue because they can focus a large amount of energy on a small area resulting in damage to the cells and often causing severe burns. Lasers can be a continuous wave (CW) or pulsed and can operate in different regions of the electromagnetic spectrum. Some of the lasers operate in the infrared red region and cannot be seen by the eye. The tissue damage depends on the power, energy per pulse, and the region of the electromagnetic spectrum in which they operate. They are often categorized as far-infrared lasers (1400 nm – 1 mm), near-infrared lasers (780 – 1400 nm), visible lasers (380 – 760 nm), and ultraviolet lasers (200 nm – 380 nm).

It should be noted that the human eye can perceive the radiation in the visible region only (380-760 nm). One should be very careful in handling ultraviolet and infrared lasers because we cannot see the beam and the invisible laser radiation can cause severe damage to the eye and the skin. Specifically, the laser beam can cause damage to the cornea and the eye lens as well as the small region of the retina on which the beam may be focused.

Procedures

Laser Safety Officer (LSO)

An individual designated by the administration who shall have the responsibility and authority to assure compliance with this plan.

Laser Safety Officer Responsibilities

1. Assure the proper classification of all lasers
2. Perform hazard evaluations for all Class 3B and 4 lasers and laser work areas
3. Specify control measures for all Class 3B and 4 lasers and assure implementation.
4. Approve laser procedures, lesson plans, facilities, protective equipment, signs and labels.
5. Assure that all laser personnel receives appropriate safety training.
6. Monitor the program, assure compliance, and maintain program records.

The LSO may have final authority in determining laser control measures and may approve alternate controls when these are appropriate. Class 3B and Class 4 lasers shall be operated only with the approval of the LSO. The LSO shall have the authority to terminate laser operations if unsafe conditions exist.

Laser Safety Committee

Members of the Laser Safety Sub-Committee

The Laser Safety Committee and the Radiation Safety committee are a combined committee that will focus on both radiation and laser safety operations at the University. The Laser Safety Committee shall include the Radiation Safety Officer, Laser Safety Officer, administrative representatives, academic department representatives who by knowledge and experience are qualified in the area of radiation and/or laser safety.

1. The LSC shall meet annually and at such times as deemed necessary by the LSO.
2. The LSC shall review laser safety policies, procedures, and training and provides consultation to the LSO as administrative and technical content experts.
3. The LSC shall review issues of concern arising from incidents, accidents, and laser hazard assessments, and make recommendations for appropriate actions.

Laser Safety Protocol

The following protocols are established to ensure the safe use of lasers and laser systems. The procedures and safety features detailed in this report must be followed by all faculty, staff, and students.

• The Radiation Safety Committee will review and make recommendations for the safe operation of lasers as a part of the laser safety plan. The recommendations will be reviewed for final approval by the Executive Safety Committee. The physics, health science, and science departments are responsible for ensuring that all operations are conducted in accordance with the laser safety plan.
• All lasers used on campus in the different departments, and the workers that use and operate the lasers must be registered, and the documentation should be submitted to the Laser Safety Officer (LSO). Particular emphasis is on the safety of the students, staff, and faculty that use the lasers.
• A safety inspection is conducted at least once each semester, and unannounced inspections will be completed if needed. The committee will review the findings from the inspection and approve any recommendations generated from such inspections and the findings. Additionally, when required, the Committee will recommend and implement the interlocking mechanisms at the appropriate entrance doors where high power lasers are located.

Training

All operators of Class 3B and 4 lasers and all incidental personnel spectators who may be allowed to enter laser controlled areas should receive a laser safety briefing before operating the laser or entering the controlled area.

All operators of Class 3B and 4 lasers shall receive approved laser safety training before operating the laser. This training includes but is not limited to, the following:

1. Familiarity with the Laser Safety Plan
2. Documented laser safety training, provided by the LSO or designee
3. Documented laboratory-specific safety training, including applicable standard operating procedures.

Medical Surveillance

Baseline eye exams are not required. An eye exam is required immediately following suspected laser exposure. Any suspected laser exposure must be reported immediately to the Laser Safety Officer.

Administrative Records

1. Audits: An audit of all Class 3B and 4 lasers and the Laser Safety Program shall be conducted annually by the LSO.
2. Records: The LSO shall maintain records that document the Laser Safety Program. These records shall include:
   • Inventory and hazard analysis for Class 3B and 4 lasers
   • Training records for operators of Class 3B and 4 lasers
   • Standard operating procedures for all Class 3B and Class 4 lasers
   • Documentation of medical surveillance, if performed
   • Laser Safety Audit (inspection) forms.

Eyewear Policy

In accordance with applicable regulations and standards, the LSO will determine the requirements and proper ocular density (OD) for protective eyewear. In general, the eyewear requirements are:

• Specifically designed laser protection eyewear is required within the nominal hazard zone (NHZ) for the operation of Class 4 lasers with exposed beams.
• Laser safety eyewear is normally required within the nominal hazard zone for the operation of all Class 3B invisible lasers and Class 3B visible lasers with powers greater than 15 mW.
• Eyewear is not required by policy for Class 3B or below visible lasers with powers of 15mW or less if other controls are adequate and if intentional viewing is less than 0.25 seconds.

Laser Beam Hazards

The laser produces a beam of high-intensity electromagnetic radiation, highly directed with little beam divergence. When the beam falls on a surface, it produces localized heating, raising the local temperature. The temperatures can cause burning, damage, deformation, discoloration of the surface. Some of these procedures are beneficially employed in laser surgery. But uncontrolled exposures can cause considerable damage to the surface. Laser exposure can be hazardous to the skin and the eye in particular. One should be particularly careful about the retinal hazards. A parallel beam of light (laser beam may be considered as approximately parallel) entering the eye is concentrated by the cornea and the eye lens by a factor of about 100,000 times. Even if one uses a low power laser such as a He-Ne laser of 1 milliWatt/mm2 ( one milliWatt is one-thousandth of one Watt) will result in 100 W/mm2 on the retina which can result in a small damaged spot on the retina. However, if the beam is not parallel or diverging or diffusively scattered, the damage is significantly less.

Non-Beam Related Safety Hazards

High Voltage and High Power Supplies

Most of the ion lasers and solid-state lasers employ high voltage and high power electrical sources. High current power sources are extremely dangerous. Persons operating these lasers should be extremely cautious, and they should wear full leather shoes as a precaution to prevent electrocution to the Earth. Normally most of the commercial laser power supplies have interlocking mechanisms so that the power supply shuts off if they are open and the high voltage terminals are not covered. One should be extremely cautious while handling the laser power supplies when they are open or if the power supply is locally made or when a commercial power supply is altered for certain applications.

Chemical Hazards

Chemical liquid hazards are not a major problem in laser laboratories. We do not use dye lasers anymore, and our tunable lasers are solid-state based. However, we do have the dye laser for the nitrogen laser which uses a cuvette that encloses a small amount (10 ccs) of the fluid. The chemicals will be disposed of as chemical wastes and not into the sink.

Gas Cylinders

All the gas cylinders have to be rigidly anchored using a chain or a belt to a wall or to the cart or to some rigid and stable support. Under no circumstances, they can be operated without properly anchoring them. If the cylinder is filled with a gas at high pressure as they normally are, if the neck is broken, they can go as a small rocket resulting in major damage to the personnel and the equipment.
The nitrogen laser uses nitrogen gas, and the waste gas is not a serious problem. However, when trace gases, such as nitrogen dioxide is used, they should be exhausted to the outside, even though only traces of the gas (parts per million level) are often used.

Laser Classifications

Lasers and laser systems are classified based on their capability of injuring personnel. All of the lasers at Adelphi University were purchased after 1980. Lasers manufactured after August 1, 1976, are classified by the manufacturer. We can safely use the manufacturer’s classification for safety purposes. As of now, Adelphi University does not have any laser fabrication program. If the situation changes at a later date, the safety classification will be reviewed and approved by the laser/radiation safety committee in consultation with the faculty member involved in the fabrication.

There are five laser hazard classes:

1. Class I lasers and laser systems cannot emit accessible levels of radiation that are capable of causing eye injury under any normal operating condition such as the lasers employed in copying machines, scanners, and printers. A more hazardous laser may be embedded in a Class I product that is not accessible during normal operating conditions but maybe during service and maintenance.
2. Class II lasers and laser systems are visible lasers which have an accessible output ≤ 1 mW. Class II lasers and laser systems are incapable of causing eye injury unless intentionally viewed directly for an extended period. The normal aversion response to bright light (blinking) protects the eye from a momentary exposure.
3. Class IIIa lasers and laser systems have an accessible output between 1-5 mW and do not pose a serious eye hazard unless viewed through optical instruments. Typical laser pointers are of this power range. Eye hazard will result if the beam is focused into the eye employing an external lens.
4. Class IIIb lasers and laser systems have an accessible output between 5-500 mW for continuous wave lasers and < 0.125 J with a 0.25-second pulse width for a pulsed laser. Class IIIb lasers and laser systems pose a serious eye hazard from viewing the direct beam or reflected (specular) beams. The laser beams are used for research.
5. Class IV lasers and laser systems have an accessible output > 500 mW for a continuous wave laser and > 0.125 J with a 0.25-second pulse width for a pulsed laser. Class IV lasers and laser systems pose a serious eye hazard from viewing the direct beam, specular reflections, and diffuse reflections. Class IV lasers and laser systems also pose skin and fire hazards. The laser beams are used for research and industrial applications.

Laser Hazards

The site of damage and threshold at which damage occurs depends on the wavelength, whether it is a small or extended source, the exposure duration, whether it is a continuous wave or pulsed, and, if pulsed, the pulse length and pulse repetition frequency.

Operating lasers under reduced external light conditions increases the optical hazards because of pupil dilation. Maximum Permissible Exposure (MPE) is the level of laser radiation that a person may be exposed to without experiencing adverse health effects.

Eye Hazards

Bio-effects of the eye are summarized in the following table:

Spectrum	Location	Effect
UV-C (200-280 nm)	Cornea	Photokeratitis
UV-B (280-315 nm)	Cornea	Photokeratitis
UV-A (315-400 nm)	Lens	Cataract
Visible (400-780 nm)	Retina	Retinal injury*
IR-A (780-1400 nm)	Retina, Lens	Retinal burn, cataract
IR-B (1400-3000 nm)	Cornea, Lens	Corneal burn, cataract
IR-C (3000-1000000 nm)	Cornea	Corneal burn

* Retinal injury can be thermal, acoustic, or photochemical.

Skin Hazards

Bio-effects of the skin are summarized in the following table:

Spectrum	Location
UV-C (200-280 nm)	Erythema, cancer, accelerated aging
UV-B (280-315 nm)	Erythema, increased pigmentation, cancer, accelerated aging
UV-A (315-400 nm)	Erythema, increased pigmentation, skin burn
Visible (400-780 nm)	Photosensitive reactions, skin burn
IR-A (780-1400 nm)	Skin burn
IR-B (1400-3000 nm)	Skin burn
IR-C (3000-1000000 nm)	Skin burn

Adelphi University Physics Department Laser Inventory

G.N. Rao – Blodgett Hall, Room 012

Laser Type	Quantity	Model	Wavelength	Power	Class
QCL Mid-infra red Invisible radiation Daylight Solutions	1	TLS-CW-MHF	6.08 – 6.16 mm	8 – 25 mW	IIIb
Ar Ion Laser Spectra Physics Visible radiation	1	2017-06S	451.9-514.5 nm	6 W	IV
Ti:Sa Laser Spectra Physics Visible radiation	1	3900S	750 – 950 nm	750 mW	IV
Nitrogen Laser Laser Photonics Visible, Pulsed	1	LN1000			IIIb
Dye Laser Laser Photonics Visible, Pulsed Tunable	1	LN107			IIIb
HeNe Laser JDS Uniphase	1	05-LGR-193	543.5 nm	5 mW	IIIa
HeNe Laser JDS Uniphase	1	Uniphase 105-1	633 nm	5 mW	IIIb
He-Ne Laser	1	NT54-154	633 nm	7 mW	III
He-Ne Laser Metrologic	1	NT61-338	633 nm	0.8 mW	IIIb
Diode Laser JDS Uniphase	2	DL6148-030	638 nm	40 mW	IIIb
Diode Laser Toshiba	2	HL6714G	660 – 680 nm	10 mW	IIIb
Diode Laser Toshiba	1	DL5038-021	630 – 645 nm	30 mW	IIIb
Diode Laser Toshiba	2	DL5147-042	650 – 665 nm	35 mW	IIIb
Diode Laser Toshiba	2	ML101J8	655 – 665 nm	45 mW	IIIb
Diode Laser Toshiba	3	FLD6A2TK	675 – 695 nm	35 mW	IIIb
Diode Laser Toshiba	2	LT030MDO	750 nm	5 mW	IIIb
Diode Laser Toshiba	1	LT027MDO	777 nm	7 mW	IIIb
Diode Laser Toshiba	1	LT027MDO	780 nm	10 mW	IIIb
Diode Laser Toshiba	1	LT015MDO	830 nm	30 mW	IIIb
Diode Laser Toshiba	1	SDL5401-H1	779 nm	30 mW	IIIb
He-Ne laser LASOS Germany	1		633 nm	50 mW	IIIb

Instructional Laboratories, Blodgett Hall, Room 003

Laser Type	Quantity	Model	Wavelength	Power	Class
He-Ne Laser	4	Metrologic	633 nm	1 mW	II
Diode Laser	1	Pasco OS-8525A	650 nm	1 mW	II

Matthew Wright – Atom Trap Research Laboratory, Blodgett Hall, Room 014

Laser Type	Quantity	Model	Wavelength	Power	Class
Diode – EC Sacher, Lynx	1	Lynx	780 nm	150 mW	IIIb
Diode – EC Sacher, Lynx	1	Lynx	780 nm	150 mW	IIIb
HeNe	1	Metrologic	633 nm	1 mW	II

Sean Bentley, Laboratory, Blodgett Hall, Room 014

Laser Type	Quantity	Model	Wavelength	Power	Class
Nd:YAG EKSPLA NL301G/SH/TH	1		355 nm No direct access to 1064 & 332 nm	output ~ 50 mJ/pulse; 5 ns pulse, 10 Hz.	IV
OPO	1		Tunable 420 – 2300 nm	The energy of pulse: 1 – 18 mJ (based on λ) 4 ns pulse, 10 Hz.	IV
Violet Laser	1		405 nm, CW	20 mW	IIIb
Fiber-Coupled Lasers	2		780 nm, CW	2.5 mW	IIIb
Helium-Neon Laser Thor Labs	1		633 nm	5 mW, CW	IIIb

Laser Safety Procedures

Eye Protection

Laser protective eyeglasses are specific to the type of laser used. The laboratory heads should procure the safety glasses that are needed for the different lasers they have in their laboratories. They should have them in adequate quantities for all the workers as well as possible visiting and temporary workers. The Adelphi University Safety Committee can help in procuring the necessary laser safety eyewear.

Additionally, the following guidelines in handling the laser beams are suggested.

• If possible, confine the laser beam to a small area and if applicable, use the beam stoppers and beam dumpers to block the beam to reduce accidental exposure of the people handling the lasers and the visitors.
• For alignment purposes, use the lowest power possible. Whenever possible use the low power He-Ne lasers (< 1 mW power) for alignment purposes
• Avoid metallic strap watches and metallic jewelry as far as possible while handling the lasers.

An adequate number of laser safety eyewear should be made available at the entrance to the room or at a place where a visitor and a worker can pick up the ware and proceed to the experimental area. It should be made clear that different eyewear is needed for different lasers that may be operating at a given time.

Control of Laser Areas

• Where Class III and higher lasers are in operation, there should be a warning with a red lamp at the entrance to the room with the sign ‘laser in operation’.
• If several lasers are in operation in a room or several groups share the room, each of the laser areas should be separated with thick black curtains or curtains that would effectively block the radiation of the particular laser.
• Locks and the warning signs should be activated when the laser is in operation.
• Appropriate instructions are given to the cleaning, maintenance personnel and other physical plant people that they should never try to enter the laser room when the laser warning signs are ‘on’ without the clearance from the laboratory head.

Laser Transportation

When lasers are moved from one room to another for experiments and/or demonstrations, the PI (head of the lab) must make sure that proper laser safety protocols are observed. If any laser of Class IV is moved from one room to another, the details should be informed to the Laser Safety Officer (LSO).
In general, it is a good laboratory practice that at least two students work at any given time so that in case there is an emergency, help is available immediately.

Instructional Laboratories

Special care should be taken by the instructors if the (freshman) students are allowed to handle the lasers for the experiments. The instructors should inform all the students in the beginning that “The students will never look directly into the laser beam” because it is hazardous. This may be repeated a couple of times and make the students repeat the statement so that they clearly understand the laser safety protocols.

Maintenance and Physical Plant Staff

Often laser-based experiments are conducted, and data acquired automatically by computers. It is necessary that the staff follow the following guidelines.

• Never enter any laser laboratory without explicit authorization from the head of the laboratory or the chair of the department. If some electrical other maintenance is needed, make sure that proper clearances are obtained before entering the laser laboratory.
• Most of the optics components are very fragile, and most of the components should never be touched because when you touch the fingers leave an oil trace that would damage the optical surface. Often you cannot even clean the surface without elaborate procedures. They are quite expensive; a simple glass piece says 1 square cm size can cost several thousand $ depending on the specifications and quality of the surface.
• Optical tables are high precision instruments and should never be used to keep any items other than the optical components. Never, never step on them under any circumstances.

Emergency Action Procedures

Always contact the Laser Safety Officer in case of an emergency. Specific recommended actions for emergencies are provided in the Adelphi University Public Safety Manual. Public Safety can be contacted at (516) 877-3511.

In case of emergency or if anyone feels that he/she may be exposed to laser hazard, please contact: