Lasers and laser systems are valuable tools in research, education, and medicine.  At Tulane University  we realize our duty to faculty, staff, students, patients, visitors, and community neighbors, and as a result have set forth a series of general policies and procedural rules covering many elements that impact the health and safety of these persons as related to laser use.  The policies and procedures fall into two broad categories; Engineering Controls and Administrative Controls.  The following page lays out, referencing the original ANSI document, the necessary controls for reducing the potential for hazard associated with some applications of lasers and laser systems.

Protective Housing (Section 4.3.1 of ANSI Standard)
A protective housing shall be provided for all classes of lasers or laser systems .  This protective housing may require interlocks.  In some circumstances, such as during research and development, and during the manufacturing and servicing of lasers, it may become necessary to operate a laser or laser system without a protective covering.  In such cases, it is up to the LSO to effect a hazard analysis and ensure that control measures are instituted appropriate to the class of maximum accessible emission level to ensure safe operation.  These controls may include, but are not limited to:

1. Laser Controlled Area
2. Eye Protection
3. Administrative and Procedural Controls
4. Education and Training

Equipment Labels (Section 4.3.14.2 of ANSI Standard)
An advisory protective housing label that indicates the relative hazard of laser radiation contained within the housing shall be placed on all removable protective housings which have no safety interlock and which can be removed or displaced during maintenance, or service, and thereby allow access to laser radiation in excess of the applicable MPE.   The laser sunburst logotype is not required on such advisory labels.

• Note: Labeling of laser equipment in accordance with the FLPPS may be used to satisfy the equipment labeling requirements in this standard.
• All signs shall be conspicuously displayed in locations where they will best serve to warn onlookers.

Requirements for Class II Lasers or Laser Systems

(Taken from the ANSI Z136.1-2000 Standard)

Lasers and laser systems are valuable tools in research, education, and medicine.  At Tulane University  we realize our duty to faculty, staff, students, patients, visitors, and community neighbors, and as a result have set forth a series of general policies and procedural rules covering many elements that impact the health and safety of these persons as related to laser use.  The policies and procedures fall into two broad categories; Engineering Controls and Administrative Controls.  The following page lays out, referencing the original ANSI document, the necessary controls for reducing the potential for hazard associated with some applications of lasers and laser systems.

Protective Housing (Section 4.3.1 of ANSI Standard)
A protective housing shall be provided for all classes of lasers or laser systems .  This protective housing may require interlocks.  In some circumstances, such as during research and development, and during the manufacturing and servicing of lasers, it may become necessary to operate a laser or laser system without a protective covering.  In such cases, it is up to the LSO to effect a hazard analysis and ensure that control measures are instituted appropriate to the class of maximum accessible emission level to ensure safe operation.  These controls may include, but are not limited to:

1. Laser Controlled Area
2. Eye Protection
3. Administrative and Procedural Controls
4. Education and Training

Equipment Labels (Section 4.3.14.2 of ANSI Standard)
An advisory protective housing label that indicates the relative hazard of laser radiation contained within the housing shall be placed on all removable protective housings which have no safety interlock and which can be removed or displaced during maintenance, or service, and thereby allow access to laser radiation in excess of the applicable MPE.   The laser sunburst logotype is not required on such advisory labels.

• Note-Labeling of laser equipment in accordance with the FLPPS may be used to satisfy the equipment labeling requirements in this standard.
• All signs shall be conspicuously displayed in locations where they will best serve to warn onlookers.

Alignment Procedures:
Laser incident reports have repeatedly shown that an ocular hazard may exist during beam alignment procedures.

Alignment of Class II, IIIa, IIIb, and IV laser optical systems  (mirrors, lenses, beam deflectors, etc.) shall be performed in such a manner that the primary beam , or a specular or diffuse reflection of that beam, does not expose the eye to a level above the MPE. 

There are many times, e.g. during servicing, when a temporary beam attenuator placed over the beam aperture can reduce the level of accessible laser radiation to levels at or below the applicable MPE level.

Written SOP's outlining alignment methods shall be approved by the LSO for Class IIIb and IV lasers and laser systems, and one copy maintained and accompanying the laser or laser system on-site, while another is maintained in the possession of the LSO.

Requirements for Class IIIa Lasers or Laser Systems

(Taken from the ANSI Z136.1-2000 Standard)

Lasers and laser systems are valuable tools in research, education, and medicine.  At Tulane University  we realize our duty to faculty, staff, students, patients, visitors, and community neighbors, and as a result have set forth a series of general policies and procedural rules covering many elements that impact the health and safety of these persons as related to laser use.  The policies and procedures fall into two broad categories; Engineering Controls and Administrative Controls.  The following page lays out, referencing the original ANSI document, the necessary controls for reducing the potential for hazard associated with some applications of lasers and laser systems.

Protective Housing- (Section 4.3.1 of ANSI Standard)
A protective housing shall be provided for all classes of lasers or laser systems .  This protective housing may require interlocks.  In some circumstances, such as during research and development, and during the manufacturing and servicing of lasers, it may become necessary to operate a laser or laser system without a protective covering.  In such cases, it is up to the LSO to effect a hazard analysis and ensure that control measures are instituted appropriate to the class of maximum accessible emission level to ensure safe operation.  These controls may include, but are not limited to:

1. Laser Controlled Area
2. Eye Protection
3. Administrative and Procedural Controls
4. Education and Training

Equipment Labels- (Section 4.3.14.2 of ANSI Standard)
An advisory protective housing label that indicates the relative hazard of laser radiation contained within the housing shall be placed on all removable protective housings which have no safety interlock and which can be removed or displaced during maintenance, or service, and thereby allow access to laser radiation in excess of the applicable MPE.   The laser sunburst logotype is not required on such advisory labels.

• Note-Labeling of laser equipment in accordance with the FLPPS may be used to satisfy the equipment labeling requirements in this standard.
• All signs shall be conspicuously displayed in locations where they will best serve to warn onlookers.

Alignment Procedures:
Laser incident reports have repeatedly shown that an ocular hazard may exist during beam alignment procedures.

Alignment of Class II, IIIa, IIIb, and IV laser optical systems  (mirrors, lenses, beam deflectors, etc.) shall be performed in such a manner that the primary beam , or a specular or diffuse reflection of that beam, does not expose the eye to a level above the MPE. 

There are many times, e.g. during servicing, when a temporary beam attenuator placed over the beam aperture can reduce the level of accessible laser radiation to levels at or below the applicable MPE level.
 
Written SOP's outlining alignment methods shall be approved by the LSO for Class IIIb and IV lasers and laser systems, and one copy maintained and accompanying the laser or laser system on-site, while another is maintained in the possession of the LSO.

Requirements for Class IIIb Lasers or Laser Systems

(Taken from the ANSI Z136.1-2000 Standard)

Lasers and laser systems are valuable tools in research, education, and medicine.  At Tulane University  we realize our duty to faculty, staff, students, patients, visitors, and community neighbors, and as a result have set forth a series of general policies and procedural rules covering many elements that impact the health and safety of these persons as related to laser use.  The policies and procedures fall into two broad categories; Engineering Controls and Administrative Controls.  The following page lays out, referencing the original ANSI document, the necessary controls for reducing the potential for hazard associated with some applications of lasers and laser systems.

Protective Housing (Section 4.3.1 of ANSI Standard)
A protective housing shall be provided for all classes of lasers or laser systems .  This protective housing may require interlocks.  In some circumstances, such as during research and development, and during the manufacturing and servicing of lasers, it may become necessary to operate a laser or laser system without a protective covering.  In such cases, it is up to the LSO to effect a hazard analysis and ensure that control measures are instituted appropriate to the class of maximum accessible emission level to ensure safe operation.  These controls may include, but are not limited to:

1. Laser Controlled Area
2. Eye Protection
3. Administrative and Procedural Controls
4. Education and Training

Protective Housing Interlock (section 4.3.2 of ANSI Standard)
Protective housings which enclose Class IIIb or IV lasers or laser systems shall be provided with an interlock system which is activated when the protective housing is opened or removed during operation and maintenance.  The interlock shall be designed to prevent access to laser radiation above the applicable MPE.

Fail-safe interlocks shall be provided for any portion of the protective housing which, by design, can be removed or displaced during operation and maintenance, thereby allowing access to laser radiation.  One may here wish to consider redundant electrical series connected interlocks.

The protective housing interlock shall not be defeated or overridden during operation.

After any and all adjustments or servicing to the laser or laser system, the interlocks must be restored to operational status.

Service Access Panel (Section 4.3.3 of ANSI Standard)
Portions of the protective housing of a laser or laser system which are designed to be removed by service personnel only, and gives them access to laser radiation, shall either be interlocked or require a tool for removal and carry an appropriate warning label.

Equipment Labels (Section 4.3.14.2 of ANSI Standard)
An advisory protective housing label that indicates the relative hazard of laser radiation contained within the housing shall be placed on all removable protective housings which have no safety interlock and which can be removed or displaced during maintenance, or service, and thereby allow access to laser radiation in excess of the applicable MPE.   The laser sunburst logotype is not required on such advisory labels.

• Note-Labeling of laser equipment in accordance with the FLPPS may be used to satisfy the equipment labeling requirements in this standard.
• All signs shall be conspicuously displayed in locations where they will best serve to warn onlookers.

Area Posting (Section 4.3.9 of ANSI Standard)
The purpose of a laser area warning sign is to convey a rapid visual hazard-alerting message that:

1. Warns of the presence of a laser hazard in the area.
2. Indicates specific policy in effect relative to laser controls.
3. Indicates the severity of the hazard (e.g. class of laser, NHZ extent, etc.)
4. Instructs appropriate action to take to avoid the hazard.

The laser warning signs shall utilize warning statements where the signal words have the following meanings:

• Danger indicates an imminently hazardous situation which will result in death or serious injury if not avoided.  Use this word only in the most extreme conditions.
• Caution indicates a potentially hazardous situation which may result in moderate or minor injury if not avoided.
• Notice is used to indicate a statement of facility policy as the message relates directly or indirectly to the safety of personnel and/or the protection of property.  This word must not be used in place of ADanger@ or ACaution@.
• All signs shall be conspicuously displayed in locations where they will best serve to warn onlookers.

Totally Open Beam Path (Section 4.3.6.1 of ANSI Standard)
In applications of Class IIIb or IV lasers where a beam path is unenclosed, a laser hazard analysis will be effected by the LSO to determine the NHZ if this information is not furnished by the manufacturer.  The LSO will define the area where laser radiation is accessible at levels above the MPE, or levels which could impair visual performance.

Limited Open Beam Path (Section 4.3.6.2 of ANSI Standard)
In applications of Class IIIb or IV lasers where the beam path is confined by design to significantly limit the degree of accessibility of the open beam, a hazard analysis will be effected by the LSO to establish the NHZ if this information is not furnished by the manufacturer.  The analysis will define the area where laser radiation is accessible at levels above the appropriate MPE and will define the zone requiring control measures.

Education and Training (Section 4.4.3 of ANSI Standard)
Education and training shall be provided for operators, maintenance, and service personnel of Class IIIb and IV lasers or laser systems.  The training will be provided by the principal investigator of the area, or an appropriately trained designee, and will be commensurate with the level of potential hazard of the laser or laser system.

Warning Signs and Labels (Section 4.7 of ANSI Standard)
Sign dimensions, letter size, colors, etc., shall be in accordance with American National Standard Specification for Accident Prevention signs, ANSI Z535 series, latest revision thereof.

Consult the LSO for approval of the signs you intend to use for your laser or laser system.

• All signs shall be conspicuously displayed in locations where they will best serve to warn onlookers.

Alignment Procedures:
Laser incident reports have repeatedly shown that an ocular hazard may exist during beam alignment procedures.

Alignment of Class II, IIIa, IIIb, and IV laser optical systems  (mirrors, lenses, beam deflectors, etc.) shall be performed in such a manner that the primary beam , or a specular or diffuse reflection of that beam, does not expose the eye to a level above the MPE. 

There are many times, e.g. during servicing, when a temporary beam attenuator placed over the beam aperture can reduce the level of accessible laser radiation to levels at or below the applicable MPE level.

Written SOP's outlining alignment methods shall be approved by the LSO for Class IIIb and IV lasers and laser systems, and one copy maintained and accompanying the laser or laser system on-site, while another is maintained in the possession of the LSO.

Personnel Authorization (Section 4.4.4 of ANSI Standard)
Class IIIb or IV lasers or laser systems shall be operated, maintained, or serviced only by authorized personnel.  A list of these authorized personnel, along with a description of what qualifies them as authorized personnel, must be submitted to and approved by the LSO.  When a change occurs, and that list is modified, a copy of that modified list must be sent to the LSO immediately.  
Lasers or laser systems with enclosed IIIb or IV lasers shall be maintained or serviced by authorized personnel if such procedures would permit access to levels which exceed the MPE.

Eye Protection (Section 4.6.2 of ANSI Standard)
Eye Protection devices which are specifically designed for protection against Class IIIb and IV lasers or laser systems shall be administratively required and their use enforced when engineering and other procedural controls are inadequate to eliminate potential exposure in excess of the applicable MPE.

Laser protective eyewear may include goggles, face shields, spectacles, or prescription eyewear using special filter materials or reflective coatings (or a combination of both) to reduce the potential ocular exposure below the applicable MPE level.

Laser eyewear shall be specifically selected to withstand either direct or diffusely scattered beams.

The eyewear shall be used in a manner so that the damage threshold is not exceeded in the Aworst case exposure@ scenario.

Skin Protection (Section 4.6.6 of ANSI Standard)
In some laser applications, such as the use of excimer lasers operating in the ultraviolet, the use of a skin cover shall be employed if chronic exposures are anticipated at exposure levels at or near the applicable MPE for skin.
 
Skin protection can best be achieved through engineering controls.  If the potential exists for damaging skin exposure, particularly for ultraviolet lasers (295-400nm) and/or laser cutting/welding application, then skin covers and/or Asun screen@ cream are recommended.  Gloves and jackets, preferably of a tightly woven material, will protect the hands and torso, respectively.

• Chronic exposure may have adverse long-term health effects not fully understood at this time.

Requirements for Class IV Lasers or Laser Systems

(Taken from the ANSI Z136.1-2000 Standard)

Lasers and laser systems are valuable tools in research, education, and medicine.  At Tulane University  we realize our duty to faculty, staff, students, patients, visitors, and community neighbors, and as a result have set forth a series of general policies and procedural rules covering many elements that impact the health and safety of these persons as related to laser use.  The policies and procedures fall into two broad categories; Engineering Controls and Administrative Controls.  The following page lays out, referencing the original ANSI document, the necessary controls for reducing the potential for hazard associated with some applications of lasers and laser systems.

Protective Housing (Section 4.3.1 of ANSI Standard)
A protective housing shall be provided for all classes of lasers or laser systems .  This protective housing may require interlocks.  In some circumstances, such as during research and development, and during the manufacturing and servicing of lasers, it may become necessary to operate a laser or laser system without a protective covering.  In such cases, it is up to the LSO to effect a hazard analysis and ensure that control measures are instituted appropriate to the class of maximum accessible emission level to ensure safe operation.  These controls may include, but are not limited to:

1. Laser Controlled Area
2. Eye Protection
3. Administrative and Procedural Controls
4. Education and Training

Protective Housing Interlock (section 4.3.2 of ANSI Standard)
Protective housings which enclose Class IIIb or IV lasers or laser systems shall be provided with an interlock system which is activated when the protective housing is opened or removed during operation and maintenance.  The interlock shall be designed to prevent access to laser radiation above the applicable MPE.

Fail-safe interlocks shall be provided for any portion of the protective housing which, by design, can be removed or displaced during operation and maintenance, thereby allowing access to laser radiation.  One may here wish to consider redundant electrical series connected interlocks.

The protective housing interlock shall not be defeated or overridden during operation.

After any and all adjustments or servicing to the laser or laser system, the interlocks must be restored to operational status.

Service Access Panel (Section 4.3.3 of ANSI Standard)
Portions of the protective housing of a laser or laser system which are designed to be removed by service personnel only, and gives them access to laser radiation, shall either be interlocked or require a tool for removal and carry an appropriate warning label.

Area Posting- (Section 4.3.9 of ANSI Standard)
The purpose of a laser area warning sign is to convey a rapid visual hazard-alerting message that:

1. Warns of the presence of a laser hazard in the area.
2. Indicates specific policy in effect relative to laser controls.
3. Indicates the severity of the hazard (e.g. class of laser, NHZ extent, etc.)
4. Instructs appropriate action to take to avoid the hazard.

The laser warning signs shall utilize warning statements where the signal words have the following meanings:

• Dangerindicates an imminently hazardous situation which will result in death or serious injury if not avoided.  Use this word only in the most extreme conditions.
• Caution indicates a potentially hazardous situation which may result in moderate or minor injury if not avoided.
• Notice is used to indicate a statement of facility policy as the message relates directly or indirectly to the safety of personnel and/or the protection of property.  This word must not be used in place of ADanger@ or ACaution@.
• All signs shall be conspicuously displayed in locations where they will best serve to warn onlookers.

Totally Open Beam Path (Section 4.3.6.1 of ANSI Standard)
In applications of Class IIIb or IV lasers where a beam path is unenclosed, a laser hazard analysis will be effected by the LSO to determine the NHZ if this information is not furnished by the manufacturer.  The LSO will define the area where laser radiation is accessible at levels above the MPE, or levels which could impair visual performance.

Limited Open Beam Path (Section 4.3.6.2 of ANSI Standard)
In applications of Class IIIb or IV lasers where the beam path is confined by design to significantly limit the degree of accessibility of the open beam, a hazard analysis will be effected by the LSO to establish the NHZ if this information is not furnished by the manufacturer.  The analysis will define the area where laser radiation is accessible at levels above the appropriate MPE and will define the zone requiring control measures.

Standard Operating Procedures (Section 4.4.1 of ANSI Standard)
The LSO shall require and approve written standard operating, maintenance, and service procedures (SOPs) for Class IV lasers or laser systems.  These SOPs shall be maintained in two locations; one with the laser equipment itself for reference by the operator, maintenance, or service personnel, and the other with the LSO.
 

Education and Training (Section 4.4.3 of ANSI Standard)
Education and training shall be provided for operators, maintenance, and servcice personnel of Class IIIb and IV lasers or laser systems.  The training will be provided by the principal investigator of the area, or an appropriately trained designee, and will be commensurate with the level of potential hazard of the laser or laser system.

Warning Signs and Labels (Section 4.7 of ANSI Standard)
Sign dimensions, letter size, colors, etc., shall be in accordance with American National Standard Specification for Accident Prevention signs, ANSI Z535 series, latest revision thereof.

Consult the LSO for approval of the signs you intend to use for your laser or laser system.

• All signs shall be conspicuously displayed in locations where they will best serve to warn onlookers.

Personnel Authorization (Section 4.4.4 of ANSI Standard)
Class IIIb or IV lasers or laser systems shall be operated, maintained, or serviced only by authorized personnel.  A list of these authorized personnel must be submitted to and approved by the LSO.  When a change occurs, and that list is modified, a copy of that modified list must be sent to the LSO immediately.  

Lasers or laser systems with enclosed IIIb or IV lasers shall be maintained or serviced by authorized personnel if such procedures would permit access to levels which exceed the MPE.

Eye Protection (Section 4.6.2 of ANSI Standard)
Eye Protection devices which are specifically designed for protection against Class IIIb and IV lasers or laser systems shall be administratively required and their use enforced when engineering and other procedural controls are inadequate to eliminate potential exposure in excess of the applicable MPE.

Laser protective eyewear may include goggles, face shields, spectacles, or prescription eyewear using special filter materials or reflective coatings (or a combination of both) to reduce the potential ocular exposure below the applicable MPE level.

Laser eyewear shall be specifically selected to withstand either direct or diffusely scattered beams.

The eyewear shall be used in a manner so that the damage threshold is not exceeded in the Aworst case exposure@ scenario.

Skin Protection (Section 4.6.6 of ANSI Standard)
In some laser applications, such as the use of excimer lasers operating in the ultraviolet, the use of a skin cover shall be employed if chronic exposures are anticipated at exposure levels at or near the applicable MPE for skin.

Skin protection can best be achieved through engineering controls.  If the potential exists for damaging skin exposure, partuicularly for ultraviolet lasers (295-400nm) and/or laser cutting/welding application, then skin covers and/or Asun screen@ cream are recommended.  Gloves and jackets, preferrably of a tightly woven material, will protect the hands and torso, respectively.   For Class IV lasers, consideration shall be given to flame-retardant materials.

• Chronic exposure may have adverse long-term health effects not fully understood at this time.

Equipment Labels (Section 4.3.14.2 of ANSI Standard)
An advisory protective housing label that indicates the relative hazard of laser radiation contained within the housing shall be placed on all removable protective housings which have no safety interlock and which can be removed or displaced during maintenance, or service, and thereby allow access to laser radiation in excess of the applicable MPE.   The laser sunburst logotype is not required on such advisory labels.

• Note-Labeling of laser equipment in accordance with the FLPPS may be used to satisfy the equipment labeling requirements in this standard.
• All signs shall be conspicuously displayed in locations where they will best serve to warn onlookers.

Alignment Procedures:
Laser incident reports have repeatedly shown that an ocular hazard may exist during beam alignment procedures.

Alignment of Class II, IIIa, IIIb, and IV laser optical systems  (mirrors, lenses, beam deflectors, etc.) shall be performed in such a manner that the primary beam , or a specular or diffuse reflection of that beam, does not expose the eye to a level above the MPE. 

There are many times, e.g. during servicing, when a temporary beam attenuator placed over the beam aperture can reduce the level of accessible laser radiation to levels at or below the applicable MPE level.

Written SOP's outlining alignment methods shall be approved by the LSO for Class IIIb and IV lasers and laser systems, and one copy maintained and accompanying the laser or laser system on-site, while another is maintained in the possession of the LSO.

Key Control (Section 4.3.4 of ANSI Standard)
A Class IV laser shall be equipped with a master switch.  This switch shall effect beam termination and.or system shutoff and shall be operated by a key, or by a coded access.  The authority for access to the master switch shall be vested in the appropriate supervisory personnel.

A single master switch on a main control unit shall be acceptable for multiple laser installations where the operational controls have been integrated.

Beam Stop or Attenuator (Section 4.3.8 of ANSI Standard)
A class IV laser shall be equipped with a permanently attached beam stop or attenuator.  This beam stop or attenuator shall be capable of preventing access to laser radiation in excess of the appropriate MPE level when the laser or laser syatem output is not required , as in warm-up procedures.

• For those lasers that do not require a warm-up time, the main power switch may be substituted for the requirement of a beam stop or attenuator.

Activation Warning System (Section 4.3.9.4 of ANSI Standard)
An alarm (e.g. an audible sound), a warning light (visible through protective eyewear), or a verbal "countdown" command for single pulse or intermittent  operations shall be used with Class IV lasers or laser systems during activation or startup.

Emission Delay (Section 4.3.9.1 of ANSI Standard)  
 

Facility Window Protection (Section 4.6.3 of ANSI Standard)
Facility windows that are located within the NHZ of a Class IIIb or IV laser shall be provided with an appropriate absorbing filter, blocking barrier, or screen which reduces any transmitted laser radiation to levels below that applicable MPE level.
Such laser windows shall be specifically selected to withstand direct and diffusely scattered beams.

Protective Equipment (Section 4.6.1 of ANSI Standard)
Enclosure of the laser equipment or beam path is the preferred method of control, since the enclosure will isolate or minimize the hazard.

When other control measures do not provide adequate means to prevent direct access to direct or reflected beams at levels above the MPE, PPE in the form of gloves or clothing, goggles or spectacles, and barriers or windows that have been specifically selected may become necessary.