KEN BARAT, LASER SAFETY SOLUTIONS
It is unlikely that anyone who has read the Z136.1: Safe Use of Lasers Standard, or any of the application standards stemming from it, is unfamiliar with standard operating procedure (SOP). By definition, SOP is a formal written description of the safety and administrative procedures to be followed in performing a specific task. In laser safety, SOP typically applies to the laser system operation and alignment.
Unlike the fluorescent bulb, for example, SOP has not evolved over the years even as it is foundational to laser safety. And while it may be logical that the essence of SOP be unchanged, there are nuances to consider, as is true of other laser safety procedural elements. Knowing when an SOP is required is critical to understanding the function and interpretation of the SOP itself. Z136.1 and Z136.9, for example, share requirements. SOP for a Class 3B laser is considered a “should,” and it is considered a “shall” for a Class 4 laser. For Z136.3 and Z136.8, it is a “shall” for Class 3B and Class 4 lasers.
SOP ins and outs
SOPs are a widespread requirement across laser systems, but the content of these procedures is inconsistent. Further, few individual standards offer SOP templates; within the ANSI Z136.1-2022: Safe Use of Lasers, for example, only the research-specific standard, Z136.8, provides templates. This means that guidelines interpreted as standard are apt to vary depending on the author of the set of guidelines.
As a result of this flexibility, any operational instruction would qualify as an SOP, essentially by default. The consensus of laser safety officers (LSOs) is that an SOP must address the hazards and the measures that users must take to protect themselves and the equipment. Once procedures are established, the signatures of all who will be working under it are required.
Knowing when an SOP is required is critical to understanding the function and interpretation of the SOP itself.
In this context, the SOP should be viewed as a contract between the user/operator and the safety department. Still, certain inherent variables must be considered. SOPs can range from a single page to as many as 40 pages. Further, some SOPs are formatted as risk assessment documents. With so much room for interpretation, one must address several questions before developing an SOP.
Generating an SOP
An approved SOP can be likened to a driver’s license: Once granted, all items, such as hand signals, for example, are rarely or never considered again. Many SOP documents spend their existence on a shelf and are not used as a reference.
The laser or laser system operator or user is the best person to write the SOP. For this reason, some institutions have created an electronic template for the user to complete. Other companies enlist the LSO to write the SOP. But this can be problematic if the LSO is unfamiliar with all the details of the required work. A meeting between the LSO and operator is a practical solution for bridging these knowledge gaps. These meetings provide an exchange of information on what work will be performed and any existing or assumed safety concerns as well as any recommendations.
SOP contents
Genericism is a common flaw in the creation of an SOP: Making the document completely generic by only containing fundamentally good practices — for example, removing reflective sources (i.e., jewelry and ID badges) and ensuring that all optics are secure — does not reflect procedure-specific controls, which are a critical safety element.
In some cases, SOPs consist of questions that help the LSO determine hazard evaluation elements and drive the user to examine use operation conditions. Questions regarding the presence or absence of unattended work, illumination level(s), and the potential for beams to be present outside of the laser control area all qualify as examples of potential hazards to both the operator and those around the laser system. Upon the completion of this step, the focus should shift to risk mitigation.
Other times, SOPs more closely resemble work operation instructions than standards. These so-called Operational Work Instructs may function as an SOP with the inclusion of certain safety steps. Also, formats of SOPs may vary. It is common in medical settings, for example, for an SOP to resemble an operational checklist. This same approach can be used in manufacturing or fabrication situations. This includes the use of Class 4 hand-held units such as those found in many laser welding and cleaning operations.
Reviewing the SOP
Standards regard the SOP as a reference document for users and operators to review (sidebar). Traditionally, this would be a paper document in a binder. Now, users may simply use a QR code to access it on a smart device. This approach works well in cleanrooms and/or other settings in which a binder is impractical.
From the perspective of the LSO, who relies on users to modify their SOP if there is an ensuing change that will influence user safety, fighting complacency is an ongoing challenge that is paramount to ensure staff safety.
From the perspective of the LSO, who relies on users to modify their SOP if there is an ensuing change that will influence user safety, fighting complacency is an ongoing challenge that is paramount to ensure staff safety.
With the availability of the SOP, there is an inherent question as to how often staff members will review it. It is often safe to assume that staff rarely reference the traditional SOP, so a safe plan of action (SPA) approach — which in many ways is the laser safety version of a construction tailgate meeting — is a strong option. With an SPA, staff meet at least once a day to review the work to be completed and agree on the control measures needed for safe and efficient operation. I first encountered this approach at the National Ignition Facility, which led to more than 5 million working hours without a lost time event.
Revisiting the SOP
All SOPs must be reviewed and renewed. Most commonly, companies and/or organizations review their SOPs annually. But even when there is little expectation of change, SOPs must be reviewed, even if it is only to update the user list. A control may have been developed or training requirements may have changed. With each revision, staff members must sign off on the updated SOP. Staff members whose training has lapsed are one of the most common deficiencies found in SOP audits.
So, what does all this mean? The SOP is a fundamental laser safety document. But it is also one that I would say is stuck in the past and needs to evolve. The nature of this evolution should depend on the environment in which the SOP is used. One size, as many have learned, does not fit all applications.
Standards and Standard Operating Procedure
Z136.1 Safe Use of Lasers-2022
Per Section 4.4.3.1 Standard Operating Procedures (Class 3B or 4), the laser safety officer (LSO) should require and approve written standard operating procedures (SOPs) for maintenance and service procedures for Class 3B lasers or laser systems. The LSO shall require and approve written SOPs for Class 4 lasers or laser systems. These written SOPs shall be maintained with the laser equipment for reference by the operator and maintenance or service personnel.
Z136.3-2018, Medical Policies & Procedures
Per Section 4.2.1 Policies and Procedures (Class 3B and Class 4) the health care framework shall establish policies and procedures. The LSO shall require approved guidelines for issued Class 3B and Class 4 health care laser systems. These established regulations shall be maintained and be readily available to users. The LSO shall further require that safety protocols exist for servicing the health care laser systems. Manufacturers and service agents assume responsibility for safety when servicing the equipment.
Z136.8 Safe Use of Lasers in Research, Development, and Testing
Section 4.3.3 Standard Operating Procedures (Class 3B and Class 4) says that the LSO shall require and approve written standard operating, maintenance, and service procedures for Class 3B and Class 4 lasers or laser systems. These procedures shall be accessible in the laser control area, either by hard copy or in an electronic format, for reference by the system users, maintenance staff, and service personnel. Continuous-wave visible lasers at or below 15 mW are exempt from this requirement.
Z136.9-2013 Safe Use of Lasers in Manufacturing Environment
Section 4.4.3.1 Standard Operating Procedures (Class 3B or Class 4) requires the LSO to have and approve written SOPs for operation, maintenance, and service of Class 3B lasers or laser systems. The LSO shall further require and approve written SOPs for Class 4 lasers or laser systems. These written SOPs shall be maintained with the laser equipment for reference by the operator and maintenance or service personnel.