Laser1
" Okay, so things go wrong and someone alerts their supervisor of a suspected laser injury. That supervisor contacts you, the installation Laser Safety Officer, and tells you the incident." What are your next steps? What are your responsibilities?
1. Ensure exposed individual seeks medical care immediately 2. Notify Safety, Public Health, JAG, and applicable MAJCOM, Reserve Command, or National Guard medical staff 3. Notify Tri-Service Laser Injury Hotline/complete a DoD laser accident/incident reporting form within 3 duty days.
Class 1M
A Class 1M laser is considered incapable of producing hazardous exposure conditions during normal operation unless viewed with collecting optics, such as binoculars. Class 1M lasers are exempt from control measure, other than to prevent potentially hazardous optical aided viewing and are exempt from other forms of surveillance.
Class1
A class 1 laser is a laser system containing a laser that cannot emit laser radiation at levels that are known to cause eye or skin injury during normal operation. Lasers can be class1 because they are very low power or because the beam is fully enclosed.
Diffuse Reflection
A diffuse reflection changes the spatial distribution of a bean of radiation when it is reflected in many directions by a surface or medium. A beam undergoing a diffuse reflection is not a beam anymore and becomes similar to a regular light source, which emits light in all directions.
Gas
A gas laser's medium can consist of commonly known gases such as helium-neon, Argon and Carbon Dioxide. This is important because some of these lasers have compressed gases linked to the system that can pose an additional industrial hygiene concern.
Specular Definition
A specular reflection is a mirror like reflection which does not change the beam spatial distribution, i.e., a beam remains a beam after the reflection - only its direction changes.
Any medical examination requirements are limited to personnel who routinely work in a laser environment with potential exposure to___ lasers.
All Classes, Class 2, Class 1 or 2, Class 3B or 4.
Barrier Labels
All commercial Protective Barriers should have lables that contain the following information: Barrier Model # Exposure Criteria Care and cleaning Laser exposure time, BTL and Beam size Specification Manufacturer I.D.
When to use barriers:
Area control can be applied in some cases using special barriers specifically designed to withstand either direct or diffusely scattered beams. The barrier should be described by a barrier threshold limit (BTL)(i.e., beam penetration through the barrier after a specified exposure time typically 60 seconds). The barrier should be located at a distance from the laser source so that the BTL is not exceeded in the worst-case exposure scenario. When to use barriers: · For permanent enclosures around a Class 3B or Class4 Controlled area · When conventional walls or windows would impede the laser process · When the laser area may be frequently moved or repositioned to a new area · For efficiency and safety during times of maintenance and service.
Local safety Organizations
As a Laser Safety Officer or LSO, you'll be in charge of the overall program at your installation. However, you'll have many partners that range from the installation commander to the individual worker. The roles and responsibilities are listed in AFI 48-139 · Installation Commander · Installation Laser Safety Officer (ILSO) · Medical Treatment Facility (MTF) Commander or Equivalent · Aerospace Medicine · Public Health · Installation Safety (SEG) · Installation Civil Engineering Fire and Emergency Services · Installation Contracting Office · Unit Commander · Unit Laser Safety Officer (ULSO) · Workplace Supervisor · Individual In some cases, the installation LSO can establish a formal laser Safety Committee or LSC. A formal LSC can be established at the direction of the installation LSO at bases where three or more units are using Class 3B and/or Class 4 FDA-compliant lasers or military specific lasers. Implementing a Laser Safety Committee is simply another way to help the installation LSO delegate duties and improve the flow of information. Class 3B and/or Class 4 FDA-compliant lasers or military specific lasers. Implementing a Laser Safety Committee is simply another way to help the installation LSO delegate duties and improve the flow of information.
Ophthalmologist Interview
As far as the eyes go, the areas at greatest risk are the retina, where the light receptors are located, and the lens, which focuses the light, and the outer protective layer, or cornea. Beyond the certain point known as the Maximum Permissible Exposure, the effects of lasers can star to cause irreversible damage. The MPE changes with wavelength and exposure durations. For instance, a Class2 laser won't cause damage for the first quarter-second, but if you continue to stare at it, you're more susceptible to injury. In general, the MPEs for the eyes are much lower than that of the skin. The MPEs are defined by the ANSI standard. Since a laser beam expands slowly with distance, the danger associated with it will decrease in the further you are away from the source. When you are far enough away that the energy of the beam drops below the MPE, that's called the Nominal Ocular Hazard Distance. If you are within the Nominal Ocular Hazard Distance you are much more susceptible to injuries.
#1 Hazard:
Biological-Eyes & Skin - The higher the classification, the more likely an injury can occur.
Investigation Report should include:
Causes, Contributing Factors, and Corrective Measures. Detailed Final report withing 30 days. Provide one copy to Medical for member record and one copy to BE Staff Level and Local Organizations.
Class 2
Class 2 lasers are low power and emit in the visible portion of the spectrum (400 to 700 nm). Under normal operation, Class 2 lasers are considered not strong enough to damage a person's eye because a person will normally blink and look away from the laser if it enters their eyes (also referred to as the aversion response)
Class 2M
Class 2M lasers are low power visible lasers (400 to 700 nm) that are a subclass of class 2. Similar to the class2/class 1M relationship, they are potentially hazardous if viewed with collecting optics. The upper limit on a continuous wave (CW) laser in this class is 500nW.
Class 3B
Class 3B lasers are subclass of class 3 lasers which may be hazardous under direct and specular reflection viewing conditions. They are not normally a diffuse reflection or fire hazard. Lasers in this class operate between 5 mW and 500 mW of CW systems and cannot produce a radiation energy greater than .125 J for pulsed systems.
Class 3R
Class 3R lasers are intermediate powered lasers, which may be hazardous under direct and "specular reflection" viewing conditions. The term specular refers to the type of reflection formal mirror or shiny/glossy surface. A CW Class 3R laser can produce no more than 5mW in the visible region
Class 4
Class 4 lasers are high power lasers which are hazardous to the eye or skin from exposure to the direct beam and may oppose a diffuse reflection or fire hazard. They may also pose ancillary hazards including laser-generated air contaminants and hazardous plasma radiation.
Which of the following materials can be used as a laser protective barrier?
Commercial barriers specifically designed to withstand direct or diffusely scatter beams
Laser safety program (per AFI 48-139 and ANSI Z 136.1) Objectives
Describe the roles, responsibilities, and interactions of stakeholders in an installation laser safety program. Using the Acronym LASERTIME
Laser Types and Hazards
Different lasers have different hazards. There are different lasers medium that create different lasers for different purposes. Different mediums will produce different wavelengths and associated hazards. The laser medium can be a gas, a solid state like a crystal, or a semiconductor like a diode and dye which is a liquid. Each of these sources poses its own type of hazard based on the wavelength emitted.
Dye Lasers
Dye lasers operate using different organic dyes. Users of these lasers can change the wavelength of the system which may require changing eye protection. These organic dyes are known carcenogens and must be handled with caution.
Questions about appropriate use and selection of laser protective barriers should be directed to:
ESOH Service Center Environmental, Safety, and Occupational Health Services
Training
Each laser operator must have the education and training level that is commensurate with the degree of hazard and responsibility. It is the workplace supervisor's responsibility to ensure that users of Class 1M, 2M, 3R, 3B or 4 lasers receive training upon initial assignment to the unit and annually thereafter. Laser safety training plans topically include the following topics. · Areas that can exceed MPE · Control procedures · Response to suspected overexposure · Bio-effects · Risk/hazard assessment · Standards, measurements · Operation of laser equipment · Personal protective equipment (PPE) · Lock-out/tag-out · Reports, investigation and risk communication · Properties of lasing as appropriate
Flammability of Laser Beam Enclosures
Enclosure of Class 4 laser beams and terminations of some focused Class 3B lasers can result in potential fire hazards if the enclosure materials are exposed to irradiances exceeding 10W/cm2. Plastic materials are not precluded as an enclosure material, but their use and potential for flammability and toxic fume release following direct exposure should be considered. Flame resistant materials and commercially available products specifically designed for laser enclosures should also be considered.
Categories of Laser Controls
Engineering, Administrative & procedural, and Personal Protective Equipment(PPE) There are three basic categories of controls that are useful in laser environments. The Air Force requires the use of ANSI Z136.1, American National Standard for Safe Use of Lasers for guidance on control measures. For additional information refer to the Bioenvironmental Engineer's Guide for Lasers and Optical Radiation which can be found on the ESOH Service Center Website:
Explosion Hazards
High-pressure arc lamps and filament lamps or laser welding equipment shall be enclosed in housing which can withstand the maximum pressures resulting from lamp explosion or disintegration. The laser target and elements of the optical train which may shatter during laser operation shall also be enclosed
Which of the following stakeholders assists the unit commander in developing policies, procedures and/or instructions to meet the requirements of AFI 48-139.
ILSO, ULSO, Public Health, Bioenvironmental Engineering
Laser Eye Protection (LEP)
LEP is Usually selected on the basis of two things 1. Optical Density (OD) - The OD of the LEP must be equal to or greater than that required by the laser. 2. Wavelength The wavelength range of the LEP must encompass the wavelength of the laser(s) being used LEP is Usually selected on the basis of two things 1. Optical Density (OD) - The OD of the LEP must be equal to or greater than that required by the laser. 2. Wavelength The wavelength range of the LEP must encompass the wavelength of the laser(s) being used
Equipment: Protective and preventative
Laser eye protection must be properly labeled and periodically evaluated. Any protective eyewear with scratches, cracks, or other signs of excessive wear must be replaced. There should be enough LEP with the proper optical density at the appropriate wavelengths to handle and workers or visitors that are required to be in the laser hazard area.
Incident Reporting/Mishap Investigation
Laser safety officers must always be prepared for the worst case scenario. A thorough knowledge of reporting and investigation procedures for accidents and overexposures is critical. Reference the "Laser Overexposures or Accidents" section of this training or AFI 48-139 for more details · Be prepared for the worst-case scenario · Know investigation procedures · Reference this training or AFI 48-139 · Actions to take after an incident o Individual § Immediately reports to workplace supervisor and the ULSO. § Through their supervisor, shall seek immediate medical care. o Workplace Supervisor § Ensures worker seeks immediate medical care § Ensures the Unit Commander, ULSO, ILSO, BE, SEG and PH are notified. o ULSO § Contacts ILSO to coordinate laser accidents/incident investigation § In coordination with Unit Commander and Workplace Supervisor, suspends unsafe laser operations until investigation is complete § Provides required information to the ILSO o ILSO § Coordinates suspected laser accidents/incidents (see the BE guide). § Creates investigation report and forwards to installation PH, BE, SEG, Medical Records, JAG, MAJCOM BE, AFMISA/SG3PB and ESOH Service Center within 30 workdays.
LASER
Light Amplification by Stimulated Emission of Radiation
Acronym Outline
Local Laser Safety Organizations Audits and Inspections Safety regulations Protective Equipment Record Keeping Training Incident Reporting/Mishap Investigation Medical Surveillance and Exams
Medical Surveillance and exams
Medical examination requirements are limited to personnel who routinely work in an environment with Class 3B or Class 4 lasers. · Pre-Employment: Laser users and personnel working in laser-operation environments shall be subject to baseline eye exams and pre-employment eye exams as determined by a qualified provider. Laser users and personnel who work with UV broadband optical sources with a history of photosensitivity or working with UV lasers shall be subject to a baseline and subsequent skin examinations to be determined by a qualified provider. · Post-Employment: Post-employment medical exams shall be performed as soon as practical subsequent to actual termination of duties involving Class 3B or Class 4 lasers (I.e. AFSC change, retirement, or separation). · Injury or Suspected Injury Follow-up: Eye exams must be conducted following any actual or suspected overexposure to laser radiation; the pertinent examinations as determined by a qualified provider shall be performed.
Beam Characteristics
Monochromatic-single color Coherent-waves travel in step Collimated- all in one direction Laser light can be; Continuous- Power is measured in watts J/s Pulsed- typically last a fraction of a second (Hertz-Kilohertz). Power is measured in joules Nm2/s2 Single Repetitive
Semiconductors lasers
Most laser pointers and hand-held aiming devices on firearms are semiconductor or diode lasers.
Visible Light Transmission (VLT)
Now you've seen how OD and wavelength factor into selecting laser safe eyewear. An additional specification you should consider is Visible Light Transmission (VLT). LEP with low VLT can inhibit worker's vision as they perform their required duties or cause other safety concerns. When selecting laser eye protection, look for LEP with the highest percentage VLT possible. This may require attracting the manufacturer or checking their website for applicable data.
Occupational Health-
Potential hazards associated with compressed gasses, cryogenic materials, toxic, and carcinogenic materials and noise should be considered. Adequate ventilation shall be installed to reduce noxious or potentially hazardous fumes and vapors, produced by laser welding cutting and other target interactions, to levels below the appropriate occupational exposure limits
Laser Components
Pumping System - The pumping system is the source of power that excites the lasting medium in order to create photons for the laser beam. This can be an electrical source, a flash lamp or even another laser. Lasing Medium - is what determines the wavelength of the system. It can be a crystal or a gas or a chemical. Optical Cavity the OC contains the lasing medium and reflective mirrors that guide the laser beam. These components provide the amplification desired to create the desired laser parameters.
Modes of Operation - Terms and Units
Radiant Energy (Q)- energy that is emitted, transferred, or received in the form of radiation; measured in Jules (J) Radian Power (Φ)) Power that is emitted, transferred, or received in the form of radiation; measured in Watts (W) Radiant Exposure (H)-(also called energy density) - radiant energy striking a surface divided by the area of that surface over which the striking energy is distributed; measured in j/cm2 Irradiance (E) (also called power density) - radiant power striking a surface divided by the area of that surface over which the striking energy is distributed; measured in W/cm2 Divergence angle (φ)—defines the rate at which a beam diameter expands or spreads over distance; commonly measured in milliradianns (mrad), 1mrad =.0573 degrees. A 1 mrad divergence means the beam diameter expands 1 mm for every meter traveled. Lasers typically have a divergence of .5 mrad. The divergence angle can be used to calculate the beam spot size at any point along the path of travel.
Collateral Radiation
Radiation, other than laser radiation, associated with the operation of a laser or laser system, e.g., radio frequency (RF) energy associated with some plasma tubes, x-ray emission associated with the high voltage power supplies used with excimer lasers, shall be maintained below the applicable protection guides,. Lasers and laser systems which, by design, would be expected to generate appreciable levels of collateral radiation, should be monitored.
Administrative & procedural
Standard Operating Procedures, Alignment Procedure, Education & Training, Output Emission Limitations, Authorized Personnel, Lase Controlled Area, and Temporary Laser Controlled Area
Safety Regulations
State, Federal, and local laser safety regulations are the foundation for laser safety policy and standard operating procedures for indoor laser operations. It's the responsibility of the installation LSO to establish local laser safety regulations. OSHA, Federal Aviation Administration, American National Standards Institute and FDA
The Lens
The Lens which focuses the light coming into the eye. It is susceptible to the UV wavelengths (300 -400 nm)
The cornea
The cornea is the tough outer layer of the eye, accounting for 2/3 of the eye's focusing power. It is susceptible to UV and IR wavelengths (<300 nm and> 1400 nm)
Solid
The first laser was a solid state laser and used a pink ruby c crystal. The most common Solid State laser is a neodymium-doped crystal: yttrium aluminum garnet, commonly known as ND_YAG.
Record Keeping
The installation LSO must keep an extensive set of records on laser systems, laser applications, and the associated personnel. · All laser devices should be reported to the Installation Bioenvironmental Engineer. They will add them to the Defense Occupational and Environmental Health Readiness System (DOEHRS) inventory. · A current inventory of laser systems · A current inventory of lasers protective devises · All applicable Standard Operating Procedures (SOPs), regulations, and instructions · A list of local laser training conducted with attendance rosters · Unit LSO certifications and dates.
Electrical Hazards
The intended application of the laser equipment determines the method of electrical installation and connection to the power supply circuit (for example, conduit versus flexible cord). Laser systems may require high-voltage power systems that pose a risk of electrocution. SPECIAL NOTE: Those personnel servicing or working on the lasers with exposed high voltages and/or the capability of producing potentially lethal electrical currents should be trained in CPR.
Nominal Hazard Zone (NHZ)
The nominal hazard zone mentioned in the preceding video describes the space within which the level of the direct, reflected or scatter radiation during normal operation exceeds the applicable MPE. Exposure levels beyond the boundary of the NHZ are below the appropriate MPE level.
Retina
The retina is in the back of the eye and contains the light receptors that can be damaged by visible and near IR Lasers (400- 1400nm)
Audits and Inspections: Routine Assessments and Inspections
The review of laser operations typically occurs by two means: Routine Assessments and Routine Inspections Control Measures Non beam Hazards Medical/biological Hazards
Standards & Regulations
There are numerous standards and regulatory agencies that impact the use of lasers in the Air Force. These standards can fall in the categories of government, military, or commercial regulations. The following is a list of prominent agencies and regulations in each category: Government FDA Center for Devices and radiological health (FDA/CDRH). The FDA/CDRH Federal Laser Product Performance Standard (FLPPS) regulates the manufacture of commercial laser products. Occupational Safety & Health Administration (OSHA). OSHA;s construction standard provides guidance of personal protective equipment such as laser safety googles. Federal Aviation Administration (FAA) Order JO 7400.2G, Procedures for Handling Airspace Matters. Establishes regulations and approval procedures for the outdoor use of lasers that may impact airspace and the air traffic within. Military DoD Instruction 6055.15, DoD Laser Protection Program. Implements policy, assigns responsibilities, and describes procedures in support of the DoD Laser Program. AFI 48-139, Laser and Optical Radiation Protection Program. The criteria in this standard represent the Air Force's minimum requirements for a laser radiation protection program. It assigns responsibilities for the healthful and safe operation of laser systems. Commercial The American National Standards Institute (ANSI). Provides standards that are intended as a guide for manufacturers, consumers, and general public. The Air Force requires adherence to the ANSI Z136 series which covers standards for the use of lasers.
Non-beam Optical Radiation Hazards-
This relates to optical beam hazards other than laser beam hazards. Ultraviolet radiation emitted from laser discharge tubes, pumping lamps and laser welding plasmas shall be suitably shielded to reduce exposure to the levels below the associated occupational and Environmental Exposure Level (OEEL)
Commercial laser protective barriers should be labeled with the barrier threshold limit (BTL), exposure time for which the limit applies, and the beam exposure conditions under which protection is afforded
True
Distances less than the NOHD are Above the Maximum Permissible Exposure value, and the are beyond the NOHD is representative of values lower than the MPE.
True
Distances less than the NOHD are Above the Maximum Permissible Exposure value.
True
Laser Bioeffects: Objectives
Upon competition of this module, you should be able to... Descrive biologic al effects of laser radiation on the skin and eyes. Explain the term Maximum Permissible Exposure (MPE) and its relevance to personnel exposed to lasers. Describe the term Nominal Hazard Zone (NHZ) and explain its importance Define the term nominal Ocular Hazard Distance (NOHD) and explain its importance
Laser Fundamental Objectives
Upon completion of this module you should be able to Identify standards governing the use of lasers in the Air Force, principles of laser operations, and classes of laser systems. Describe common laser technologies and sources and associated beam and non-beam hazards.
Overexposures (Investigation): Objectives (per AFI 48-139 and ANSI Z 136.1)
Upon completion of this module, you should be able to identify the requirements for laser injury reporting and investigations following laser overexposures or accidents
Control Measures
· Area Warnings signs · Entryway controls such as door interlocks or entryway curtains · Kill switches · Visible/audible warning systems · Protective housing/beam blocks to keep laser energy contained · Inspect to see that no laser path is at eye level or for a person sitting or standing in the room
Medical/biological Hazards
· During medical procedures, viruses can be aerosolized and expose personnel. Measures should be taken to prevent the spread of infections. · Dead and live cellular material can become aerosolized · Increased fire hazard with bottled oxygen.
Non-beam Hazards
· Electrical hazards such as high voltage power supplies. · Compressed gases for gas lasers such as CO2 · Chemical hazards such as laser dyes can be carcinogenic · Laser Generated Air Contaminant (LGAC): Any time high powered lasers are burning/etching materials the gases created must be vented as regulated under normal ventilation procedures. This can include laser etchers and medical laser applications · Mechanical hazards: Some laser systems are operated on robotic arms and couse pinch points or moving hazards to consider
Laser Controls (LEP, Barriers, Etc) Per AFI 48-139 Objectives
· Explain the categories of laser controls and give examples of each. · For consultation assistance, the ESOH Service Center is available to help in all routine assessments.
Personal Protective Equipment (PPE)
· Laser Eye Protection & Protective Clothing
Engineering
· Protective Housing, Protective Housing Interlocks, Service Access Panels, Master Switch Control, Beam Stop or Attenuator, Remote Interlock Connector, Warning labels, Barriers and Protective Curtains.