SEMI S10-1296 SAFETY GUIDELINE FOR RISK ASSESSMENT.pdf.pdf

1SEMI S10-1296 SEMI 1996 SEMI S10-1296 N/A SEMI 1996 SAFETY GUIDELINE FOR RISK ASSESSMENT 1 Purpose 1.1 This document provides a method for assessing the risk associated with any hazard and for ranking dif- ferent hazards according to the risks they present. The method can be used to differentiate between those haz- ards which are acceptable and others which require further mitigation to reduce their risk to acceptable levels. 2 Scope 2.1 This method is applicable to hazards associated with semiconductor facilities, processes and manufac- turing equipment. It is used to evaluate the risks pre- sented by identifi ed hazards and provides consistent basis for prioritizing corrective action and allocating of limited resources according to the risks those hazards present. 3 Referenced Documents None. 4 Terminology 4.1 hazard A condition that is a prerequisite to a mishap. 4.2 likelihood The expected frequency with which a mishap will occur. Usually expressed as a rate (e.g., events per year, per product, per wafer processed). 4.3 mishap An unplanned event or series of events that results in death, injury, occupational illness, dam- age to or loss of equipment or property, or environ- mental damage. 4.4 risk The expected losses from a mishap, expressed in terms of severity and likelihood. 4.5 severity The extent of the worst credible loss from a mishap caused by a specifi c hazard. 5 Procedures 5.1 Mishap Severity users should develop groupings that are consistent with their own organizations hazard control objectives and safety policies. NOTE 2: Likelihood and severity may vary, depending on the activity phase (e.g. operation, maintenance or service.) 5.2 Risk Assessment Matrix Once a hazards risk is determined, decisions can be made about whether the risk is acceptable or whether further mitigation is nec- essary. The Risk Assessment Matrix (such as the example shown in Figure 1) is a tool for making this judgment in a consistent, repeatable way. The risk assessment categories tend to group together hazards with similar loss potentials (e.g., rare cata- strophic loss and a frequent minor loss). The contours shown in Figure 1 are not standardized and users should defi ne the matrix to suit their specifi c risk assessment criteria. Besides establishing the risk assessment category for a single hazard, the matrix can be used to compare and prioritize different risks. This makes it easier to iden- tify and concentrate resources on hazards having the greatest risk. The matrix can also be used to determine the effectiveness of alternative risk reduction strategies so that cost effective hazard reduction can be imple- mented. 2SEMI S10-1296 SEMI 1996 * These descriptions are for example only. Use measures that are appropriate for your specific application. Figure 1 Sample Risk Assessment Matrix Table 1. Severity Grouping Severity GroupPeople*Equipment/Facility*Property* 1 - CatastrophicOne or more fatalities.System or facility loss. Chemical release with acute, lasting environmental or public health impact. 2 - SevereDisabling injury/illness.Major subsystem loss or facility damage. Chemical release with temporary environmental or public health impact. 3 - ModerateMedical treatment or restricted work activity (OSHA recordable). Minor subsystem loss or facility damage. Chemical release triggering external reporting requirements. 4 - MinorFirst aid only.Non-serious equipment or facility damage. Chemical release requiring only routine cleanup without reporting. Table 2. Likelihood Grouping Likelihood GroupExpected Rate of Occurrence* A - Frequent More than fi ve times per year. B - Likely More than once per year, but no more than fi ve times per year. C - Possible More than once in fi ve years, but no more than once per year. D - Rare More than once in ten years, but no more than once in fi ve years. E - UnlikelyNo more than once in ten years. 3SEMI S10-1296 SEMI 1996 6 Related Documents 6.1 SEMI Standard SEMI E10 Standard for Defi nition and Measure- ment of Equipment Reliability, Availability & Main- tainability (RAM) 6.2 United States Military Documents1 MIL-STD-882C System Safety Program Require- ments MIL-SPEC-1629A Procedures for Performing a Failure Mode Effect and Criticality Analysis 6.3 European Standard2 EN 1050 Safety of Machinery - Risk Assessment NOTICE: These standards do not purport to address safety issues, if any, associated with their use. It is the responsibility of the user of these standards to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. SEMI makes no warranties or representations as to the suitability of the standards set forth herein for any par- ticular application. The determination of the suitability of the standard is solely the responsibility of the user. Users are cautioned to refer to manufacturers instruc- tions, product labels, product data sheets, and other relevant literature respecting any materials mentioned