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EH&S Support

The environmental, health and safety (EHS) regulations that affect a facility are an ever-changing, complex myriad of rules. It is necessary to identify, track and address regulatory requirements while shifting from obtaining and maintaining regulatory compliance to actively managing activities, procedures and processes to minimize or eliminate the need for compliance.
Earth Tech Microelectronic Services Group tracks the changes, understands the rules, and provides the right information on what is required by government regulations. In addition, we provide EHS support ranging from sampling to design consultation to meet our client¹s demands of regulatory requirements. The following describes the EHS support we provide in more detail.

• Indoor Air Quality
• Implementing Laser Safety Programs
• Ergonomic Assessments
• Ventilation Assessments for Facilities
• Implementation Of An Industrial Hygiene Sampling Program

Indoor Air Quality

Indoor air quality concerns are a serious potential issue that can result in disruption of the worksite and cause employee concerns about the workplace, loss of productivity and, in some cases, sickness among employees. This has traditionally been a primary concern in office buildings; however, the presence of odors, irritants and other types of agents is an issue at all worksites. A major factor associated with indoor air quality issues is that many of the occurrences involve low concentrations at levels that are difficult to clearly associate with specific sources or operations.

Responding to indoor air quality issues is an important part of a good employee health and safety program because of the perception that can develop among employees that the workplace is unsafe. Determining whether the issue is based upon a hazardous condition is important in making sure that the perception does not become a major problem.

Evaluations of indoor air quality issues are typically based upon performing a series of tests to determine the concentrations of chemicals present in the air and, when possible, identifying the source of the chemicals. In cases where the symptoms indicate a potential biological sources (e.g. molds and fungi), we utilize bio-aerosol sampling to identify areas with high concentrations of bio-aerosols and possible sources in those areas.

Controls to prevent the release of chemicals is based upon the same types of designs used for other chemical emissions, ventilation, restricting the area of use or substitution with less volatile / hazardous chemicals. Controls for biological concerns include:

• Replacing contaminated materials,
• Cleaning affected areas with biocide,
• Preventing leaks of water from roof systems and
• Inspecting / cleaning the HVAC system regularly

Implementing Laser Safety Programs (click here for Laser Safety)

Facilities using lasers are required to implement laser safety programs to ensure that employees are adequately protected against exposures to hazardous lasers. The standard used in the United States for this type of program is the ANSI Z136.1 ­ 2000; "Safe Use of Lasers". The ANSI Standard provides a detailed set of information on the types of controls and programs needed for facilities using lasers. The types of controls and extent of the programs needed is based upon the types of lasers used.

The first step in creating a laser safety program is to develop an inventory of the lasers in use and to catalog the areas where lasers are used. The program should identify the controls needed including PPE for personnel working near lasers. Exposures to lasers can be quantified based upon the information about the lasers in use. The ANSI Standard establishes Maximum Permissible Exposure (MPE) limits for lasers based upon the power of the laser beam, wavelength and duration of exposure. This provides an important means of comparing the exposures received with the recommended limits to determine if additional controls are required.

The Laser Safety Officer (LSO) for the facility is the individual assigned the responsibility for overseeing the Laser Safety Program and working with users of lasers to ensure that adequate controls are incorporated and employees are provided with protection against exposures. The LSO helps to establish the controls needed using the criteria in the ANSI Standard.

The selection of the correct laser goggles is important for those tasks that require that the beam be worked with in an open beam path (e.g. laser beam alignment) and cannot be performed with the housing present. Laser goggles are designed for specific lasers based upon the wavelength and power of the laser. Laser goggles cannot be used interchangeably for different lasers with different wavelengths or power levels. Laser goggles should be selected and used for specific laser operations and are specified in terms of the wavelength and the optical density (OD). The optical density is the ratio of the power of the laser beam to the MPE limit for the laser. The OD is a logarithmic function, thus, an OD of 10 would indicate that the power of the laser is 10^10 (i.e. 10,000,000,000) times the MPE for the laser beam.

Earth Tech provides assistance to Laser Safety Officers and their facilities in setting up laser safety programs, providing employee training and assessing exposures to lasers for comparison with MPEs.

Ergonomic Assessments (click here for Ergonomics)

Ergonomic reviews of manufacturing operations and production lines is a technique designed to reduce the incidence of cumulative trauma injuries, acute ergonomic injuries and improve the efficiency of these operations. Ergonomic reviews involve assessing the types of tasks performed, the postures used during these tasks, the materials handled and the tools involved. The ultimate goal of these reviews is to identify those operations that present the greatest potential for ergonomic injuries and implement controls or modifications to reduce these risks. The SEMI S8 Guideline has been developed to address product design criteria for semiconductor manufacturing equipment. This guideline also provides criteria that can be used for manufacturing applications. The use of SEMI S8 and other ergonomic references provides a set of criteria for evaluating manufacturing and production operations to reduce the risk of ergonomic injuries. In addition, the design of manufacturing production operations that reduce the stress on personnel and improve the working conditions can also achieve improvements in the efficiency of the production process and ultimately increase productivity. Earth Tech provides ergonomic consulting services for semiconductor manufacturing operations including production design reviews, employee training and assessments of individual tools or processes.

Ventilation Assessments for Facilities

Ventilation assessments are performed to determine the effectiveness of the exhaust ventilation, verify that the distribution of exhaust in a facility is appropriate for the types of equipment being used and ensure that the control of chemical emissions is adequate. Ventilation assessments are also performed to verify that the exhaust ventilation system is still operating effectively as additional pieces of equipment are connected to the system. The types of assessments performed depend on the types of operations where ventilation is being used. Tracer gas testing is a methodology that was originally developed for evaluations of equipment. The SEMI F15-90 Tracer Gas Test Method describes a technique for evaluating the effectiveness of exhaust ventilation in controlling the release of toxic chemicals from exhausted enclosures. However, this test method can also be used for assessments in facilities. Tracer gas testing can be used effectively to verify that ventilation zones are separated and cross-contamination from one zone to the next is not occurring. This test method involves releasing a tracer gas in one zone and documenting that the gas is not present in other zones.
Tracer gas testing can also be used to document that the concentrations of chemicals released from a specific storage area or equipment will not pose a fire hazard in areas where electrical equipment is present. Tracer gas testing can also be performed in facilities to document the quantities of chemical emissions potentially released from chemical enclosures (e.g., gas distribution panels mounted near chemical systems, or gas interface boxes used in the facility). Tracer gas testing can also be used to optimize the amount of exhaust required at individual tools. Given the high cost of exhaust in semiconductor facilities, this type of assessment can produce major cost savings for the facility. Earth Tech provides tracer gas testing consulting services for facilities along with ventilation assessments for individual tools and facility systems.

Implementation Of An Industrial Hygiene Sampling Program (click here for Ventilation Safety)

The implementation of an industrial hygiene monitoring program should be based on the following steps:

• Developing a prioritized IH sampling plan that identifies the operations, tasks and potential health hazards to be addressed
• Industrial hygiene monitoring of the operations and tasks in the Plan
• Reviewing the data to determine if additional controls are needed
• Implementing controls, as required
• Follow-up sampling to document that the controls are adequate to reduce exposures to acceptable levels

Results from the sampling program should be provided to employees in accordance with OSHA requirements (e.g., 29 CFR 1910.1000). This is a critical part of the sampling program because it provides information to employees about tasks they may have questions on and documents the results. If specific operations have levels that are high, the steps being taken to address these areas should be explained to employees. IH sampling programs are based upon an initial baseline assessment of operations and tasks using the information from the IH sampling plan. Follow-up monitoring may be warranted in the following cases:

• To confirm elevated levels obtained for specific operations,
• To document the effectiveness of implemented controls,
• To assess the impact of changes to the operations (e.g., new chemicals, new tools, new equipment, new procedures),
• To assess the range of exposure levels for tasks that may have a large variation in factors affecting the exposures (e.g. large variation in duration of the tasks, or large variation in the amount of chemistry used)
• Follow-up sampling to document that the controls are adequate to reduce exposures to acceptable levels.

A key step in assessing chemical exposures is to determine in advance what the evaluation criteria will be for the sample results before the sampling is performed. In most cases, this will be the established exposure limit from OSHA or the ACGIH TLV. In some cases, the manufacturer will provide a recommended limit to customers in its MSDS for the chemical or in separate documentation. If there is no established exposure limit, sampling should generally not be performed until a means of assessing the results is determined. Obtaining results without an evaluation criteria has the potential to create concerns and questions where there are no easy or readily available answers.