Laboratory Construction Procedure Appendix – Laboratory Design
General Requirements for Design of Laboratories
1. The contract documents must contain an equipment and furnishings schedule that includes necessary product identification, function descriptions, handling, mechanical and electrical equipment/accessories, hardware indications, installation accessories and finishes.
2. Laboratories must meet the requirements of the National Fire Protection Association (NFPA) 101, “Code for Safety to Life From Fire in Buildings and
Structures.” Occupancy classification must depend upon the building in which the
laboratory is located and the nature of the work performed in the laboratory. Laboratories must be classified as one of the following occupancies: A. Business
3. Laboratories must conform to one of the following NFPA standards: A. NFPA 45: Standard on Fire Protection for Laboratories Using Chemicals
B. NFPA 99: Standard for Health Care Facilities
4. Biohazard containment facilities must comply with guidelines published by
the Center for Disease Control and Prevention and the National Institutes of Health, “Biological Safety in Microbiological and Biomedical Laboratories.”
5. Biohazard Containment Facilities and Devices
5.1. PROHIBITED: Volatile hazardous chemicals (including natural gas) in biohazard
cabinetry, unless the cabinet is entirely exhausted to the outside. Biohazard cabinets must comply with NSF/ANSI Biological Standard 49 for
Class II Biohazard Cabinetry.
5.2 Minimal use of alcohol and other disinfectants to clean the inside
of the cabinet is permissible in cabinets that are not entirely exhausted to the outside. More than minimal/incidental use of chemicals requires a risk assessment (contact Environmental Health
and Safety). T he type of cabinet (non exhausted, partially exhausted or fully exhausted) and ducting system selected
will depend upon a thorough risk assessment of the organisms, chemicals and processes intended to be used. See guidance from the Centers for Disease Control for further information (http://www.cdc.gov/od/ohs/biosfty/bsc/bsc.htm).
5.3. Laminar flow clean air devices such as clean benches must comply
with Institute of Environmental Sciences (IES) Standard IES-RP-CC002.
Since laminar flow clean benches provide only product particle protection,
not operator or environmental protection, hazardous physical, chemical
or biological agents cannot be safely used in these devices.
5.4 To start the design process for a Biosafety Level 3 facility, complete the checklist in Appendix – BSL3 Checklist to
facilitate communication between project team members, university staff and outside agencies. Each project team needs to create a project-specific checklist by reviewing the generic checklist to identify the items that pertain to that specific project and add or amend items as needed.
6. Compartmentalization of each laboratory unit must be achieved by providing
it with at least:
A. One-hour fire-rated separation from adjacent laboratories or other areas
B. Self-closing fire doors with at least a 20-minute fire rating
C. Class A interior finishes
D. Class I floor finishes
E. Doors to corridors from laboratories that swing in the direction of exit
7. Provide a minimum of two exits in laboratories larger than 200 square feet, where hazardous materials are used.
8. Aisles serving a single work area must be a minimum of 36 inches wide. Double aisles must be a minimum of 60 inches
wide. Avoid aisles longer than 20 feet. Arrange furniture for easy access to an exit from any point in the laboratory.
9. Faucets, to which a hose or similar device may be attached, must be providedwith an approved vacuum breaker.
Alternately, a special laboratory water supply equipped with an RPZ back flow device to separate it from the potable
water maybe provided. If a laboratory water system is provided, all connected outlets must be labeled “Not Potable.”
10. A safety shower and eyewash must be provided in each lab area equipped with a fume hood. In other laboratories using
chemicals, eyewash must be required. If feasible, control the water supply to a temperature between 60 degrees F and 95
degrees F. Refer to Appendix S - Emergency Eyewash and Safety Shower Installation. All rooms where Biosafety Level
2 and above organisms are manipulated require an eyewash and a hand wash sink.
11. Provide a single shut-off valve for each laboratory in accessible locations or central supply of flammable, combustible or
oxidizing gases. Valves must be outside of the areas in which the gases are used. These shut-off valves are in addition to
those at the points of supply and use. They may be located adjacent to the corridor exit from the lab or, if security is not a
problem, in the corridor.
12. Storage and supply systems for compressed and liquefied gases mustcomply with requirements of NFPA and ANSI.
Consult the following standards:
A. NFPA 50, Standard for Bulk Oxygen Systems at Consumer Sites
B. NFPA 50A, Standard for Gaseous Hydrogen Systems at Consumer Sites C. NFPA 50B, Liquefied Hydrogen Systems at Consumer Sites
D. NFPA 51, Design and Installation of Oxygen-Fuel Gas Systems for Cutting and Welding
E. NFPA 54, National Fuel Gas Code
F. NFPA 55, Compressed and Liquefied Gases in Portable Cylinders G. NFPA 58, Standard for the Storage and Handling of Liquefied
H. NFPA 99, Standard for Health Care Facilities
Chapter 3 - Use of Inhalation Anesthetics (flammable and non-flammable) Chapter 4 - Use of Inhalation Anesthetics in Ambulatory Care Facilities Chapter 5 - Respiratory Therapy
I. ANSI B31.1.0, Power Piping, including Addenda B31.1.0(a),
B126.96.36.199(c) and B188.8.131.52(d)
J. ANSI B31.2, Fuel Gas Piping
K. ANSI B31.3, Petroleum Refinery Piping
13. Systems for other gases must comply with the manufacturer’s
recommendations. "The Handbook of Compressed Gases" by the Compressed Gas Association and the "Matheson Gas Data Book" by Matheson Gas Products may be consulted as a reference standard.
14. Controls for air, gas and other utilities must be color-coded and labeled in accordance with the Scientific Equipment and Furniture Association (SEFA) 7 as
Number Service Color Code Color of Letter
1 Cold Water Dark Green CW White
2 Chilled Water Brown CH White
3 Hot Water Red HW White
4 Steam Black STM White
5 Air Orange AIR Black
6 Gas Dark Blue GAS White
7 Vacuum Yellow VAC Black
8 Distilled Water White DW Black
9 Oxygen Light Green OXY White
10 Hydrogen Pink H Black
11 Nitrogen Gray N Black
12 All Other Rare Gases Light Blue Chemical Symbol Black
14. Provide fire extinguishers based on the basis of the area protected and hazard class. Refer to NFPA 10. Provide an UL-listed, 5 pound multipurpose dry chemical fire extinguisher with at least a 1A20BC rating mounted near an exit for each laboratory unit.
15. Laboratories Using Hazardous Chemicals
15.1. PROHIBITED: Recirculation of exhaust air from laboratories,
except in a clean room with an air lock.
15.2. PROHIBITED: Returned air from corridors in laboratory areas.
Supply air to the corridor only.
15.3. Laboratories using hazardous chemicals must be under .01 inches WG (2 PA) negative pressure with respect to adjacent areas.
16. Provide at least 30 percent pre-filter and an 80 percent filter meeting ASHRAE 5276 dust spot efficiency filters in the air supply. Air filters must be located downstream of the fan.
17. Humidifiers must be located downstream of fans and filters. Indirect clean
steam humidifying is required.
18. Labs where hazardous chemicals are used in closed systems or in a fume hood must have between six and 12 air changes per hour. Where open use of hazardous chemicals is planned, 10 or more air changes per hour must be necessary.
19. Special purpose exhaust devices must be designed with reference to the latest edition of "Industrial Ventilation: A Manual of Recommended Practice by the American Conference of Government Industrial Hygienists."
20. Reagent grade 3 water is adequate for central building distribution. Reagent grade 3 water, as specified by the College of American Pathologists or the National Committee for Clinical Laboratory Standards, is resistive at 25 degrees C of 0.1 megohms/centimeter and a pH between 5 and 8. If needed, higher-grade water can be generated at the point of use. Refer to Division 15, Section 15400 - Plumbing, item 3. High Purity Water Systems for more information.
21. Outlets must be provided for fixed appliances, and one duplex must be provided for each 3 feet of bench length or more often if required by the program. Identify emergency power outlets in accordance with Division 16, Section 16140 - Wiring Devices.
22. Provide ground fault circuit interrupters (GFIs) on electrical outlets within 6 feet of all sinks.
23. To facilitate long-term maintenance and remain flexible about reusing casework, metal casework must be provided. The following items are preferred in chemical laboratories and may be required when appropriate:
A. Metal laboratory furniture with stainless or 1-inch epoxy resin bench top
B. Wall cabinets with a continuous enclosed front plane to the ceiling C. Chemical-resistant waste lines
D. A glassware cleaning sink at least 12 inches deep
24. Laboratory floors, walls and doors require the following items:
24.1. Floors must be covered with a smooth, non-porous, seamless sheet that is resistant to a wide range of chemicals. The sheet must have a cove along walls and permanently placed furnishings. Floor openings must be sealed watertight.
24.2. Walls and doors must be constructed or painted with a smooth, non-absorbent, washable material.
24.3. Lighting fixtures must be flush-mounted with the ceiling and have removable, easily cleaned diffusers.
25. When infectious agents, human body fluids and general microbiology products are generated, an autoclave must be designated to handle decontamination. It must be provided with a dedicated exhaust to control odors. The exhaust system must include a canopy over the door to the autoclave.
26. Provide adequate storage volume for research chemicals and waste. Chemical resistant storage trays must be furnished to contain a spill of free liquid in the storage unit. Refer to Appendix - Laboratory Casework.
Laboratory Construction Procedure Appendix – Fume Hoods
1. Provide fume hoods that safely capture hazardous, flammable, corrosive or toxic chemicals, and that allow for changes in laboratory function and fume hood use. 2. Governing Regulations
2.1. See Appendix – Laboratory Design for
a list of governing regulations and reference standards.
2.2. University of Minnesota Standards and Procedures for Construction must be reviewed for specific specifications on material and equipment. These are general standards for typical research uses. In special circumstances, different standards may apply.
3. General Features
3.1. PROHIBITED: Installing heated drying base cabinets under fume hoods. 3.2. Fume hoods in research laboratories must comply with ANSI/AIHA Z9.5 Class A performance standards. Capture efficiency as installed and used must be at least 4 AUO.1 per ANSI/ASHRAE.
3.3. Locate fume hoods in distal corners of a laboratory and away from high traffic areas to avoid high turbulence and blocking an exit if there is an emergency.
3.4. Provide 2 lineal feet of storage space for each lineal foot of fume hood width. Refer to Division 12, Section 12345 - Laboratory Casework. Ventilate half of this space. Provide sufficient storage space to protect new and waste chemicals. Without adequate storage space, containers of waste chemicals are often boxed and stacked on the floor where they might be broken and cause injury. 4. Laboratory Ventilation Systems
4.1. Laboratory ventilation systems shall be addressed with the Department of Environmental Health and Safety (DEHS), Facilities Management and the code officials during the program phase of the design process.
4.2. Ensure that the laboratory is under negative pressure and has at least four air changes per hour. Labs where hazardous chemicals are used in closed systems or in a fume hood shall have between six and 12 air changes per hour. Where open use of hazardous chemicals is planned, 10 or more air changes per hour shall be necessary.
4.3. Noise from the laboratory ventilation system shall not exceed NC 45 throughout the laboratory.
5. Supply Air Requirements
5.1. PROHIBITED: Auxiliary air supply hoods.
5.2. PROHIBITED: Cross drafts in rooms.
5.3. To ventilate efficiently and minimize turbulence, diffuse supply air from behind the operator. Consider technology that diffuses air in a radial manner with high volume and low velocity, or pattern-control technology.
6. Exhaust System Requirements
6.1. PROHIBITED: Modulating or controlling fume hood exhaust volumes to
balance air requirements for air conditioning or heating.
6.2. PROHIBITED: Fire or smoke dampers in any chemical fume exhaust duct. 6.3. Systems shall be installed in accordance with the requirements of NFPA 91, Standard for the Installation of Blower and Exhaust Systems.
6.4. High duct velocity results in high noise levels, excessive leakage and high power consumption. Therefore, air velocity on the suction of the fan shall be a minimum of 1,000 feet per minute (fpm) and shall not exceed 2,000 fpm under any circumstances. A velocity of 1,200 fpm is recommended.
6.5. The average fume hood face velocity shall be 100 +/- 10 fpm with the vertical-sliding sash at 18 inches above the work surface. Also, on hoods wider than 4 feet, the safety shield must be in place. Readings shall be measured in the center of several square grids measured in the plane of the face opening. In addition, individual face velocities shall not exceed 20 percent of the open-face velocity average.
6.6. Fume hoods shall run continuously to minimize potential hazards when the fume hoods are off. Only the maintenance staff shall control the on/off switches. 6.7. General-purpose fume hood ductwork shall be 304 stainless steel. The fan and housing shall be corrosion resistant. Special purpose hoods may be constructed of other materials only after thorough review with DEHS and the user.
6.8. Ductwork shall be round to ensure uniform airflow.
6.9. Laboratory units shall have a one-hour, fire-resistance rating. Sheet metal ductwork usually provides one-hour fire separation. Where more than one-hour, fire-rated separation is required or if the use of combustible ductwork materials is proposed, a ductwork enclosure may be needed to meet the required fire rating. 6.10. General-purpose fume hoods shall be ducted individually. However, up to four hoods in the same room may be connected to a common exhaust duct leading from that room to an exhaust fan. If more than one hood is connected to an exhaust duct, a balanced, drop without a damper must be engineered or blast gate dampers must be provided. Fume hoods provided with filter enclosures always shall be individually ducted.
6.11. Fume hood exhaust systems shall function independently of the general building HVAC system.
6.12. Provide an independent exhaust system for associated equipment in the same room such as flammable liquid storage cabinets, biological safety cabinets and atomic absorption units. In exceptional circumstances, associated equipment may be exhausted into the fume hood ductwork. On hoods with filter enclosures, associated equipment shall be connected between the hood and the filter enclosure.
7. Exhaust Filter Enclosures
7.1. PROHIBITED: Proprietary or custom-sized filters and pre-filters.
7.2. Exhaust filters are not normally required or even recommended. However, if a filter is necessary, comply with the following provisions:
7.2.1. The filter enclosure must be airtight and constructed of stainless steel.
7.2.2. When a filter enclosure is required, it shall be easily accessible from the outside of the hood. The filter enclosure shall provide bag-in/bag-out
of filters, so the maintenance staff is not exposed to collected material. 7.2.3. Provide an indicator on hoods with a filter enclosure that is clearly visible and indicates when the pressure drops across the filter.
7.2.4. Use a standard-size pre-filter and charcoal and/or HEPA filter on the filter enclosure.
7.2.5. To allow for filter loading, the initial, average face velocity of the fume hood shall be 120 fpm with the sash at 18 inches and a clean filter. 8. Fans and Discharge
8.1. PROHIBITED: Square to round fabric connectors.
8.2. PROHIBITED: Radial-blade, paddle-wheel type centrifugal fans.
8.3. Use forward or backward curved industrial duty fans for fume hood systems. Select fans that have a chemical resistant coating and meet selected noise criteria. 8.4. Discharge ducts and fan housing shall be airtight when fans are installed in an equipment room. Fan shafts shall be sealed with a stuffing box shaft seal or equivalent device. Alternatively, install a fan with wheel back plate fins that pull air into the fan from the shaft opening. Seamless welded ductwork shall be installed on the discharge side of the fan. Transition fittings between the fan housing and discharge ductwork shall be factory fabricated with round connections. Flexible connectors shall have flanged ends and shall be factory fabricated.
8.5. Provide rain protection that does not increase discharge air pressure or deflect air downward.
8.6. Stack-design and discharge velocity shall distribute contaminants outside the eddy current envelope of the building. On structures with roof areas at more than one level, discharge ducts within 30 feet of a higher level shall terminate at a point at least 10 feet above the elevation of the higher level.
8.7. Consider clustering discharge ductwork or inducing outside air to help dilute discharge and increase the mass of the air column. Doing so raises the height of the column stack.
8.8. Maintain the maximum distance from fresh air intakes on the building and on adjacent buildings. Maintain at least 100 feet between fume hood exhausts and fresh air intakes.
8.9. Ventilate the equipment room where fume hood exhaust fans are located. 9. Fume Hood Construction
9.1. Non-combustible, corrosion-resistant construction is required. 9.2. Use an airfoil design to minimize air turbulence entering the hood. 9.3. Provide a vertical sliding safety glass sash that is balanced and counterweighted so it can be raised or lowered with one hand from any point along the bottom.
9.4. The vertical sliding safety glass sash shall have a positive steel mechanical latch 18 inches above the work surface. The latch prevents the operator from opening the sash above 18 inches without intervention. The operator shall be able to handle the latch with one hand and close it from any position.
9.5. Provide an 11-inch wide to 12-inch wide horizontal sliding safety-glass shield on hoods that are 4 feet and longer. The shield shall be suspended on bearings or slide in an easily cleaned channel. It must be supported so pressure is
not displaced and the user cannot remove it.
9.6. A removable safety shield is permitted on hoods that are 4 feet or shorter. When a removable shield is provided, do not consider the area of the shield when calculating the exhaust volume of the fume hood.
9.7. Provide an air by-pass so that the face velocity of the hood does not exceed 200 fpm as the sash is lowered.
9.8. Locate electrical outlets on the exterior of the fume hood.
9.9. Locate utility controls for gas, water and vacuum on the exterior of the hood with utility outlets mounted on the interior sidewall. Label and color-code controls.
9.10. Provide a liquid-tight work surface built to contain at least 3/8-inches of liquid.
9.11. Mount cup sinks on a raised lip to partly contain a spill before the liquid flows into the sink. The cup sinks shall be 1/16 of an inch lower than the surrounding raised margins of the work surface.
9.12. Provide an electronic airflow indicator with an audible alarm in a conspicuous location so that the user can see the status of the airflow. Set the low airflow alarm at 80 fpm.
9.13. Interior lighting shall be vapor-sealed and covered with a safety glass lens. Bulbs shall be changeable from the exterior of the hood. Illumination levels at the working surface shall be at least 80 foot-candles.
10. Additional Requirements: Radioisotope Fume Hoods
10.1. Contact DEHS for construction requirements pertinent to the user’s license.
10.2. The interior lining and baffles of the fume hood shall be smooth, polished, type 304 stainless steel. The need for seamless welded construction depends upon NRC license requirements. Usually, seamless welded construction is not required. 10.3. The work surface shall be capable of supporting up to 200 pounds per square foot of shielding material.
10.4. Work surface corners shall be smooth, seamless stainless steel with 1/2-inch radius.
10.5. An exhaust filter enclosure with a pre-filter and a HEPA and/or charcoal filter usually is not required for radioisotope hoods. If required, however, the enclosure must meet the specifications detailed in item 7. Exhaust Filter Enclosures of this appendix.
11. Additional Requirements: Perchloric Acid Fume Hoods
11.1. PROHIBITED: Connecting perchloric acid hood ductwork to other exhaust equipment.
11.2. Hoods and exhaust ductwork shall be constructed of acid-resistant, nonreactive, impervious materials. All duct work seams and joints shall be welded and watertight.
11.3. Ductwork shall be installed in the shortest and straightest path to the outside. Provide positive drainage back to the hood.
11.4. A water spray system shall be provided to wash down the entire exhaust system from the hood interior behind the baffle, through the fan, and up to the roofline. The hood work surface shall be watertight with a minimum depression of 1/2 inch at the front and sides. An integral trough shall be provided at the rear