Safety protocols for renovations in controlled environment

By Richard Jensen, Gregg Conboy and Stephen Craft, erland construction inc.

Rapid change and technological advancement in the high-tech industry demand flexible, responsive and safe facilities. In addition to new cleanrooms, second, third and fourth generation facilities require upgrades to enable companies to meet production demands. Shutting down a facility for construction is not feasible, and construction must be planned in a way to avoid interfering with ongoing operations.

When building in these special occupied environments, cleanroom contractors need to be committed to implementing safety protocols in accordance with the high-tech industry`s hazardous production materials safe handling standards. Contractors with proven safety programs are an essential element of safe operations.

Safety first

Roughly 80 percent of the substances found in cleanroom environments are considered hazardous production materials (HPMs) — materials that are flammable, reactive, corrosive or toxic. Managing construction within such an environment requires safe hand ling procedures, technical knowledge of industry requirements and a sophisticated communications capability.

Looking to governmental and industrial safety standards for guidance in developing safe construction procedures, one finds guidelines that identify substances and limits of exposure which are intended for use in manufacturing and R&D. Facilities personnel often devise their own safe handling procedures using these guidelines for assistance. Unfortunately, few safety guidelines exist for construction renovations in occupied cleanroom environments. Clean-build contractors must establish their own safe construction protocols.

More than any other type of interior building construction, cleanrooms require minute-by-minute attention to safety. To maximize safety and efficiency during construction, the owner, the designer, and the construction manager must use a cooperative approach. Tailoring their processes to suit the project, the team must coordinate planning and construction throughout the life of the project. Further complicating the coordination process, the team must communicate with user groups along effected utility lines.

Within the purview of the contractor is the analysis of existing conditions in controlled environments. Whether expansion is involved, real estate changes hands, or new owners plan to renovate older cleanrooms, it is common to discover a lack of documentation of hazardous materials. Labs may have relocated, personnel may have transferred elsewhere, and alterations to equipment and a history of service are undocumented or unavailable. New owners and builders cannot operate safely under these circumstances. Thus, identification of hazardous materials and residues found in existing facilities is the first priority. Buildings can be tested through independent firms that perform Hazard Survey Analyses (HAS).

Identifying HPMs

A Process Hazard Analysis (PHA) team should be established during planning. The owner and contractor assign a PHA team specialized in renovation and expansion. The PHA team tests air quality, hazardous materials and residues, equipment and MEP system operations.

Construction is only ready to go forward when a full understanding of conditions exists and a plan for managing conditions is in place. The owner and contractor should examine and become aware of conditions with assistance from the PHA team. The following guidelines are helpful for facilities and construction operations:

1. Emergency procedures should be in place and understood.

2. Determine state of deterioration of systems and equipment. A condition of deterioration is not readily detectable in many situations.

3. Fluid hazards. Quantities of HPMs vary within the cleanroom environment. Experience is required with handling and spill procedures. Chemicals are usually stored in small quantities within the fab. These items

must be clearly identified and empty containers disposed of properly.

4. Gas hazards. Most of the processes that take place within the cleanroom utilize gases ranging from argon and oxygen to phosphine and silane. Each type of gas has its own specialized handling and piping requirements. Are flammable gases present? What are the other characteristics of the gas? Pay attention to the use of combustion supporting materials near operations that are combustible. Flash points of HPMs must be considered.

5. Waste hazards. These come in three forms: acids, solvents and exhausts. Wastes are handled within pipes specifically designed for carrying these products. Examples include gas line, Enfield piping, Fuse-seal, stainless steel exhaust piping and fiberglass reinforced plastic. Process exhaust is a major concern when the exhaust system is shut down. The velocity of air moving through the ductwork continues to pull the exhaust. When systems are shut down, exhausts migrate to the lowest point in the ductwork and condense. Drainage requires a valved drain assembly in good working order. Know what is being exhausted. Are the exhaust fans on emergency power and are back flow dampers and traps functioning properly?

6. Stored energy, a hidden hazard. Stored energy can be found in electrical systems, equipment using compressed air and mechanical systems. Lock-out/tag-out procedures check for energy discharge. Energy discharge can also be verified by a volt meter and a water or compressed air pressure gauge. Notify all personnel prior to this procedure. The actual lock-out device is a system which holds an energy isolating device in a safe position preventing the operation of a machine. The lock-out device is tagged with the name of the operator and cannot be removed by anyone but the operator.

Without following these guidelines, simple errors can result in potentially dangerous outcomes. For example, imagine that construction is underway, and there is a company-wide shutdown of operations. Power is shut down, and the exhaust fans are turned off. Because fans are not on emergency power, gas is filtered back in the fab creating a potentially dangerous situation. By following the proper PHA documentation outlined above, dangers like this are averted.

In addition, using lock-out/tag-out procedures ensures that machinery or equipment is isolated from all potentially hazardous energy. This procedure is carried out prior to performing, servicing or maintenance activities where the unexpected energization — start-up or release of stored energy — could cause injury. Sources of energy include, but are not limited to: electrical, mechanical, hydraulic, pneumatic, chemical, and thermal.

Personal safety guidelines

Over half of all cleanroom accidents are caused by chemical burns. The following personal safety guidelines are essential for every worker and are part of a comprehensive safety program for cleanroom construction:

1. Wipe down all surfaces twice.

2. Know where the nearest emergency eye wash and shower are located. If one does not exist, set up a temporary facility.

3. Always rinse gloves after use and make sure they are the last item you remove.

4. Wear eye gear or face gear at all times.

Remember, the key to cleanroom safety is awareness, procedure and safety gear. Two out of three is not good enough. You have got to have it all!

In summa ry, as increasing numbers of industries utilizing cleanrooms for manufacturing processes come on line, contractors will need to be prepared to adapt to the owner`s site-specific safety protocols developed for each company`s process. The challenge for contractors is to be ready to gain the necessary knowledge to work effectively for the owner, and to have the flexibility to adapt safety procedures accordingly.

Richard Jensen is a project executive for Erland Construction, Inc. (Burlington, MA) in the Advanced Technology Division. He has been with Erland for 16 years. Gregg Conboy and Stephen Craft are project managers with Erland for 10 and 16 years, respectively. Erland`s staff is certified in controlled environments, safety protocols and contamination control. Erland is a construction management and design/build firm.

For more information

The American Conference of Governmental Industrial Hygienists publishes the threshold limit values that are considered the maximum safe exposure limits for hazardous production material substances. In addition, OSHA sets legal standards for permissible exposure limits.

American Conference of Governmental Industrial Hygienists

1330 Kemper Meadow Drive

Cincinnati, OH 45240

Tel 513/742-2020

Occupational Safety and Health Administration

Office of Information & Consumer Affairs

Tel 202/219-8151

Web address: http://www.osha.gov