Building codes, laboratory design, and high technology research and development

Building codes, laboratory design, and high technology research and development

Buikhg codes, laboratory design, and high technology research and development By David Rainer H ave you read and are you familiar with your local b...

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Buikhg codes, laboratory design, and high technology research and development

By David Rainer

H

ave you read and are you familiar with your local building codes? In North Carolina, we have a state building code modeled after the Southern Building Code, and all new construction and building modifications are required to comply with code requirements. There are no exceptions for state facilities, and we too at NC. State University must comply with all code standards. As with all building codes, the purpose of the N.C. code is to, “serve as a comprehensive regulatory document to guide decisions aimed at protecting the public’s life, health, and welfare in the built environment.“’ The N.C. and other codes specify minimum design requirements. Additional safeguards may be required for each project depending on the type of occupancy, structure, or type of hazards. There are currently three “model” codes utilized by most states and or local jurisdictions in the United States. The term “model” is used, because most states adopt or use one of the three “model” codes or incorporate the fundamental organization and content of one of the model codes into respective state or local codes. When a model code is adopted by a state or ----

____-is Director of the Environmental Health and Safety Center at North Carolina State University. Mr. Rainer also works with EBI, a full service EHGS consulting firm to high technology companies and universities.

David Raker

38

local municipality, the code has the effect of law and must be followed. Generally, the model codes are utilized as follows: west of the Mississippi is the Uniform Building Code developed by the International Conference of Building Officials (ICBO); east of the Mississippi, Building Offrcials and Code Administrators International National Building Code (BOCA); and southeast, Southern Building Code Congress International (SBCCI). There is also currently a nationwide effort underway to standardize the three model codes. The new code is being promoted and written under the direction of the International Code Council (ICC), which should issue a first edition sometime during the year 2000. ’ In 1994, the ICC was established by officials of BOCA, ICBO, and SBCCI to develop a single set of comprehensive and coordinated national codes. In the mid-to-late 198Os, the ICBO began to address issues related to hazardous materials use and storage. The primary intent of the code writers was to deal with fire safety issues in the semiconductor industry, but the codes also impacted laboratory operations. BOCA and SBCCI were not as comprehensive in this area until the early 1990s. The model codes and their derivatives that currently exist and that have been adopted by the various states impose a maze of requirements on architects, designers, and health and safety personnel. The codes are also highly interpretive in that the intent of the code writer is not always crystal clear, and the various code sections are sometimes contradictory.

0 Division of Chemical Health and Safety of the American Chemical Society Published by Elsevier Science Inc.

Also, many consensus standards are referenced in the model codes and these too may need to be followed when designing and building facilities. Consensus standards referenced in the model codes include, but are not limited to: . National Electrical Code (NEC) . National Fire Protection Association (NFPA) Standards 3 l NFPA 99 Fire Protection for Health Care Facilities l NFPA 45 Fire Protection for Laboratories l NFPA 101 Life Safety Code l NFPA 318 Fire Protection for Cleanrooms Additionally, there are consensus guidelines that in all likelihood are not referenced in your respective code such as Semiconductor Equipment and Materials International (SEMI) guidelines4 that nevertheless represent generally accepted industry practice. SEMI guidelines are utilized throughout the semiconductor industry and also have direct applicability to research laboratory environments, including the processing of semiconductor materials in physics, material science, or engineering laboratories. Anyone retrofitting, designing, or building a laboratory utilizing extremely hazardous materials would be remiss to ignore SEMI guidelines for: l l l

Chemically heated baths; Flow limiting orifices; Compressed gas compatibility storage requirements, etc. 1074-9098/99/$20.00 PII S1074-9098(99)00035-O

and

Table 1. Exempt

Quantities

Conditions Unprotected by sprinklers or cabinets Within cabinet in unsprinklered building In sorinklered biilding, not in cabinet In sprinklered building, within cabinet

of H4 Materials*

Highly Toxic Gasesl,’ (cu ft) 0

Toxic Compressed Gases’z2f4(cu ft) 650

20

1300

0 2600

40

Highly Toxic and Toxic Solids and Liquid3 (Ibs) Highly Toxic Toxic 500 1

Corrosives, Irritants, Sensitizers, and Health Hazard Solids, Liquids, and Gases Solids Liquids Gases (W (f.&) (cu fi) 5000 500 650

2

1000

10,000

1000

1300

2

1000

10.000

1000

1300

4

2000

20,000

2000

2600

1 lb = 0.4536 kg 1 gal = 3.7854L

1 cu ft = 0.02832m3 * Source: Table 308.2D of the 1994 North Carolina State Building Code, Volume I, p 42. Notes: 1. No exempt amounts are permitted in Group A, M, R, and offices in Group B occupancies. 2. Except for cylinders not exceeding 20 cu ft stored within a gas storage cabinet or fume hood, no exempt amounts are permitted in Group E or I occupancies or in classrooms. 3. A conversion of 10 lbs/gal shall be used. 4. Compressed chlorine gas shall have an exempt amount of 810 cu ft.

Various insurance industry groups such as Factory Mutual (FM) have standards that are applicable to laboratories. For example, the FM standard on fire prevention in combustible wet benches addresses5 important fire safety issuesconcerning hoods made of polypropylene, a readily combustible material used in chemical and laminar flow hoods in cleanrooms. At N.C. State University, the Environmental Health and Safety Center works cooperatively with Principal Investigators, and the North Carolina Department of Insurance (the authority that reviews and approves construction documents and issuesand interprets the NC Building Code) to assureappropriate safeguardsare included in laboratory designsand that the intent of the code writers is met. However, while these codes may be effective for manufacturing facilities, they are often not appropriate for research and development facilities and often create burdens and obstaclesto be overcome in the research environment. Chemical

Health & Safety, September/October

BUILDING CODE ISSUES THAT MAY AFFECT LABORATORY CONSTRUCTION

The North Carolina State Building Code referenced for this discussionis modeled on the Southern Building Code Congress International, Inc. model code. The other model codes may contain similar provisions. A “hazardous occupancy” or group “H” occupancy is a building in which “the manufacturing, processing, generation, storage, or other use of hazardous materials in excess of certain quantities occur,” (see Table 1 for quantity limits). Group H hazardous occupancies are divided into subcategories Hl, H2, H3, and H4. Hl covers buildings where materials that present a detonation hazard such asfireworks may be processedor stored. H2 covers buildings where materials that are a deflagration hazard may be processed or stored such as combustible liquids that are in open containers or pressurized. H3 covers buildings where materials that support combustion or present a physical hazard may be processedor stored. H3 hazards include aerosol products and other unstable 1999

or reactive materials. The section having the greatest potential impact on laboratories is H4, becauseH4 covers buildings or parts thereof, “used for the manufacturing, processing,generation, or storage of materials which are health hazards. Health hazards include toxic and toxic compressed gases,highly toxic and toxic solids, liquids, corrosives, irritants, sensitizers, and other health hazards . in excessof the amounts given in Table 308.2D,” (seeTable 1). It is important to look at the appropriate section(s)of the code governing your area, because definitions and allowable chemical quantities may be different. Table 2 lists some definitions applicable to hazardous materials from the N.C. Building Code. Becausethe code definitions are so broad, and quantities of chemicalsare so restrictive, it is easy for a laboratory or laboratory building to fall under the jurisdiction of the code. For example, a typical 4.5-ft-tall compressedgascylinder contains 200 cu ft of gas.A research areawith HCl, Cl,, NH, or other typical “toxic” gasescan easily exceed exempt amounts. Semiconductor, solid state 39

Table 2. Definitions

from the North Carolina

State Building

Code, Volume

Hazardous Materials--those chemicals or substanceswhich are physical hazards or health hazards as defined and classified in 407 whether the materials are in usable or waste condition. Health Hazard-a classification of a chemical for which there is statistically significant evidence based on at least 1 study conducted in accordance with establishedscientific principles that acute or chronic health effects may occur in exposed persons. The term “health hazard” includes chemicals which are carcinogens, toxic or highly toxic agents, reproductive toxins, irritants, corrosives, sensitizers,hepatotoxins, nephrotoxins, neurotoxins, agentswhich act on the hematopoietic system, and agentswhich damagethe lungs, skin, eyes, or mucous membranes. Highly Toxic Material-a material which produces a lethal dose or lethal concentration which falls within any of the following categories: 1. A chemical that has a median lethal dose (LD,,) of 50 milligrams or lessper kilogram of body weight when administered orally to albino rats weighing between 200 and 300 gramseach. 2. A chemical that has a median lethal dose (LD,,) of 200 milligrams or lessper kilogram of body weight when administered by continuous contact for 24 hours (or lessif death occurs within 24 hours) with the bare skin of albino rabbits weighing between 2 and 3 kilograms each. 3. A chemical that has a median lethal concentration (LC,,) in air of 200 parts per million by volume or lessof gas or vapor, or 2 milligrams per liter or lessof mist, fume or dust, when administered by continuous inhalation for one hour (or less if death occurs within 1 hour) to albino rats weighing between 200 and 300 grams each.

physics, material science, or other research areasthat utilize hydrides such as ASH,, PH,, B,H, will almost certainly exceed exempt amounts. Another factor impacting designrequirements is how the code is interpreted locally. You may be able to compartmentalize your laboratory spacesso that you stay below the exempt amounts of hazardous materials that may be stored, dispensed, or used. Compartmentalization is facilitated by segregating building into “control areas” (seeFigure 1). The control areasmust be separated from other areas by one-hour fire-resistive construction with 3/4-hour rated doors with self or automatic closing devices. By establishing laboratories or floors as control areas,you may be able to accommodate the use of hazardous or highly hazardous gasesin quantities greater than would be allowed if your entire building was defined as a control area. The maxi40

1 Mixtures of these materials with ordinary materials, such as water, may not warrant a classification of highly toxic. Any hazard evaluation which is required for the precise categorization of this type of material shall be performed by experienced, technically competent persons. Toxic Material-material which produces a lethal dose or a lethal concentration within any of the following categories: 1. A chemical or substancethat has a median lethal dose (LD& of more than 50 milligrams per kilogram but not more than 500 milligrams per kilogram of body weight when administered orally to albino rats weighing between 200 and 300 gramseach. 2. A chemical or substancethat has a median lethal dose (LD,,) of more than 200 milligrams per kilogram but not more than 1,000 milligrams per kilogram of body weight when administered by continuous contact for 24 hours (or lessif death occurs within 24 hours) with the bare skin of albino rabbits weighing between 2 and 3 kilograms each. 3. A chemical or substancethat has a median lethal concentration (LC,,) in air more than 200 parts per million but not more than 2,000 parts per million by volume of gasor vapor, or more than 2 milligrams per liter but not more than 20 milligrams per liter of mist, fume or dust, when administered by continuous inhalation for 1 hour (or lessif death . . occurs _ within 1 hour) to albino rats weighing between 200 and 300 gramseach.

mum number of control areas per floor in a multistory building is four and the maximum number allowed per building is ten. Again, it is important to consult your local code and code authority, because some codes allow fewer control areas. The definition of toxic and highly toxic gas or chemical may also come into play. The “authority having jurisdiction” (i.e., your local code official), has the latitude to determine if a toxic material meetsthe codes definition of toxic. For example, if you are using ASH, or PH, in a flammable or inert mixture at 100sor 1000sof ppm, you may be able to define hazard basedon the true hazard of the dilute mixture. However, numerousjurisdictions have interpreted the code as requiring conformance regardlessof the hazard of the mixture, and if you have ppm concentrations of ASH, in H,, for instance,the ppm concentration may be viewed as being the samehazard as 100% ASH,; Chemical

hence, no credit is allowed at lower concentration to put you under the exempt amount. Other problem materials include the pyrophoric gasessuch as silane. Silane in inert mixtures at concentrations of 2% or lessare not of the sameorder of hazard of 100% silane. Nevertheless,the true hazard may be ignored by somejurisdictions requiring you to count the nonhazardousmixture as hazardous. Flammable gasesare another hazard class for which meeting requirements for exempt amounts may also be difficult, especially in older research buildings that are unprotected by sprinklers and where no gasstorage cabinets exist. For example, the authority having jurisdiction may count forming gas (mixtures of nitrogen and hydrogen where hydrogen is 10% or lessof the mixture) or other nonflammable gas in the flammable gas category. Sometimes, material safety data sheets (MSDS) may help, if they de-

Health & Safety, Septemberktober

1999

TEC

Hazardous

Microektronic

Labs

Microelectronic

Labs

Microelectronic

Labs

Materials

North

Carolina

FacUm

Floor

Hazardous

State

University

Plan ~ov:

RESEARCH + TECHNOLOGY SECOND Figure

1. North Carolina

State University

BUILDING II

FLOOR Facility Floor Plan: Research

fine the true hazard of a mixture. However, often the MSDS do not account for the lack of hazard of a mixture and only reiterates the hazard of the neat product. Building codes also contain other Chemical

Materials

Health & Safety, September/October

and Technology

provisions that may affect your design and safety decisions. The N.C. code prescribes many other requirements when hazardous materials are used. Emergency power is required for exhaust ventilation, treatment 1999

Building

II, Second Floor.

systems, gas detection systems, emergency alarm systems; and temperature control systems may be required. Gas cabinets with self-closing and latching doors, sprinklers and window access are required, as 41

is gas detection and explosion ing in certain instances.

vent-

DISCUSSION

Because of the difficulty in applying the building code to laboratory and research environments, some local authorities have been proactive in developing laboratory specific codes. To address issuesrelated to the use of hazardous materials in research, Santa Clara County, California is taking the lead in developing standards specific to research laboratories. The Santa Clara proposed ordinance is intended to provide some flexibility in allowing the use of hazardous gases over the exempt amounts. Provisions of the Santa Clara ordinance limit cylinders of hazardous gasesto lessthan 15 lb. or 340 standard cu ft except for highly toxic gases,which are limited to 20 standard cu ft at normal temperature and pressure. The duration of the experiment shall be limited to 30 days or less. Other safety provisions apply including sprinklered facilities, ventilation to dilute worst-case releasesto % IDLH (the concentration that is immediately dangerous to life and health) at the point of discharge to the atmosphere, emergency power on exhaust systems, flow-restrictive orifices on cylinders, and area and/or room monitoring when required by a certified industrial hygienist. The impact of new building codes and enforcement of old building codes is significant and costly and will influence how universities do businessand designand build their facilities. Many types of researchlabs, including solidstate physics, material science, semiconductor research and development, as well as chemistry and chemical engineering, use hazardous materials that are tightly regulated by existing code requirements. The traditional arguments-that universities use extremely small quantities of hazardous materials, that hazardous materials are used by trained researchers, and that the diversity of researchprograms requiring fast changes are all factors that mitigate the need for the same type of controls as used in production environments-are moot. The fact is,

42

very prescriptive codes are in place and being enforced in many parts of the country, and the new codes are not being written to accommodate research and development activities. To a certain extent, code writers are justified in their concern for the laboratory environment. Codes are primarily intended to address fire and life-safety issues,and fire and emergency respondersare concerned about public and community safety. The fact is, the infrastructure of many research and development laboratories leaves something to be desired. Often laboratories are in older unsprinklered buildings and co-located with teaching laboratories and cleanroom space. Researchequipment is not always assembledwith adequate diligence, and electrical safety, gas safety, and processsafety design are secondary considerations. Universities also utilize nonstandard equipment that is continually modified, and they also may accept donated equipment that does not include up-to-date components. To help support code changes that will accommodate research activities, universities need to be more proactive in the code development process, in changing the safety culture at their respective institutions, and in communicating with local code authorities. At North Carolina State University, we have addressedcode and safety issues in several different ways. Although we have petitioned to have some of our local codes changed and have provided supporting information, we have found that the code change processis too time-consuming and meeting-intensive, Therefore, we have focused attention on other areas. We have a process safety review program designedto evaluate research projects using hazardous materials. The program is intended to help assure that single-point process failures do not cascadeto catastrophic system failures, with serious safety consequences.We have developed electrical safety designguidelines for laboratory equipment, have a gas monitoring standard, have developed standard gas handling manifolds for hazardous gases.and also have a pressurevessel

Chemical

safety review committee. However, what our safety program promotes (that no code can easily accommodate) is professional judgement. Our local code officials know how our safety program operatesand know our commitment to process safety. Code officials have also toured our laboratories to seethe controls we have voluntarily implemented. If environmental health and safety personnel feel that it is warranted, we have asked that minimum code requirements be exceeded in certain situations. This has helped us when we negotiate over the interpretation of codes or request that we be allowed to implement “equivalent” controls, (e.g., control a specific hazard other than in a way specifically allowed in the code). We also have a closeworking relationship with our local fire department and train with their Hazmat personnel. The bottom line is that universities need to be more proactive in safety program development and implementation, and we could speak with one voice and begin to provide more input to the code development process.Perhaps this will be easierwith standardization of codes and issuance of one code through the International Code Council. The fact is, university research and development laboratories do have hazardous operations, but code regulations may not be the costeffective or prudent way to control potential hazards in the research environment. References 1. North Carolina State Building Code, 1996edition,issuedby the North Carolina BuildingCode Counciland North CarolinaDepartmentof Insurance:Raleigh, NC. Copyright 1994 Southern Building Code International, Inc. Birmingham,AL. 2. International Code Council. http:// codes.icbo.org/ICC-2000/Mission/

3. National Fire Protection Association. Quincy, MA. 4. Semiconductor Equipment and Materials international (SEMI) Facility and Safety Guidelines. Mountain View,

CA. 5. Factory Mutual ReferenceDocument, 7-7, 17.12R,January 1997,“Semiconductor Fabrication Facilities,” Norwood, MA.

Health & Safety, September/October

1999