Health & Safety Design Considerations for Laboratories

For any new construction or renovation of laboratory areas, consider health, safety and regulatory compliance issues early in the design stage of the project. The following outlines some of these issues:

• Layout
• Furniture and Fixtures
• Storage
• Laboratory Ventilation
• Emergency Equipment
• Materials Handling
• Utilities
• Other
• Project Checklist

Layout

• Laboratory space should be physically separate from personal desk space, meeting space and eating areas. Workers should not have to go through a laboratory space where hazardous materials are used in order to exit from non-laboratory areas. Consider making visible separation between lab and non-lab space, for instance with different flooring.
• Fire-rated hallway doors should have magnetic hold-open features, such that the door will close in the event of an alarm.
• Doors to laboratories should not be fire-rated unless necessary.
• Entryways should have provisions for mounting emergency information posters and other warning signage immediately outside the laboratory (e.g., on the door).
• Each door from a hallway into a lab should have a view panel to prevent accidents from opening the door into a person on the other side and to allow individuals to see into the laboratory in case of an accident or injury.
• Laboratory areas with autoclaves should have adequate room to allow access to the autoclave and clearance behind it for maintenance. There should also be adequate room for temporary storage of materials before and after processing. Autoclave drainage should be designed to prevent or minimize flooding and damage to the floor.
• For laboratories using radioactive materials:
• Eating and drinking areas should be physically separate and conveniently located.
• Allow for security of laboratory and materials.
• Consider designing the lab to allow separation of radioactive materials use from other laboratory activities.

Furniture and Fixtures

• Work surfaces should be chemical resistant, smooth, and readily cleanable, such as chemical-grade Formica.
• Work surfaces, including computer areas, should incorporate ergonomic features, such as adjustability, appropriate lighting and equipment layout.
• Benchwork areas should have knee space to allow room for chairs near fixed instruments, equipment or for procedures requiring prolonged operation.
• Handwashing sinks for particularly hazardous chemicals or biological agents may need elbow or electronic controls.
• Wet chemical laboratories and darkrooms should have solvent resistant coved flooring using sheet goods rather than tile, particularly in areas where fume hoods are located.
• Do not install more sinks or cupsinks than are necessary. Unused sinks may develop dry traps, resulting in odor complaints.
• Sink faucets and hose bibs that are intended for use with attached hoses are provided with back siphon prevention devices.

Storage

• Cabinets for chemical storage should be of solid, sturdy construction. Hardwood or metal shelving is preferred. Some may require ventilation.
• Materials of construction should be carefully considered where corrosive materials will be stored, e.g., corrosive-resistant liners or trays on shelves, location away from copper fittings, etc.
• Allow space within the building for any central chemical and biological or radioactive waste storage needs.
• Wall shelving should have heavy-duty brackets and standards and should be attached to studs or solid blocking. For office spaces, bookcases are preferable to wall-mounted shelving.
• Flammable liquid storage needs should be defined in advance so that the laboratory may have space for a suitable number of flammable storage cabinets. Per the Uniform Fire Code, quantities greater than 10 gallons of flammable liquids must be stored in a flammable liquid storage cabinet, unless safety cans are used. No more than 25 gallons of flammable liquids in safety cans may be stored outside a flammable liquid storage cabinet.
• Flammable liquid storage is not allowed below grade or near a means of egress, per the Uniform Fire Code.
• Flammable storage cabinets should not be vented unless there is a significant odor or vapor control concern.
• Laboratories using corrosive liquids should have ample storage space low to the floor, preferably in low cabinets, such as under fume hoods.
• Allow space for the variety of waste collection containers needed. Depending on the laboratory, these may include laboratory trash, broken glass, sharps, recyclable containers, used oil, medical waste, and/or radioactive waste.
• Laboratories using compressed gases should have recessed areas for cylinder storage and be equipped with devices to secure cylinders in place.
• All laboratories should have storage space for supplies and combustible materials, e.g., boxes of gloves, spill kits, boxes of centrifuge tubes, etc.

Laboratory Ventilation

• Laboratory ventilation rates should ensure 8-10 air changes per hour minimum for occupied spaces and 6 air changes per hour minimum when unoccupied.
• Bypass style fume hoods should be used. Auxiliary air hoods should not be used.
• Fume hoods should have recessed work surfaces to control spills.
• The location of fume hoods, supply air vents, operable windows, laboratory furniture and pedestrian traffic should encourage horizontal, laminar flow of air into the face of the hood, perpendicular to the hood opening. Hoods should be placed away from doors and not where they would face each other across a narrow isle.
• Hoods may have a face velocity of 100-125 linear feet per minute with the sash fully open or at its standard configuration (e.g., at the stopper height).
• Each hood must have a continuous monitoring device, such as a magnehelic gauge. The device should display either air velocity or static pressure, rather than only an audible alarm.
• Supply air vents should be placed away from or directed away from fume hoods to avoid interference. Air velocity caused by supply vents should not exceed 25 feet per minute at the face of the hood.
• Noise from the fume hood should not exceed 65 dBA at the face of the hood.
• Use hard ducting for the positive side of exhaust ducting for all internal (penthouse) fans to prevent contaminant leakage into work areas.
• Fume hood exhaust ducts must not contain fire dampers.
• Unless otherwise specified (e.g., clean rooms), air pressure in the laboratory should be negative with respect to the outer hallways and non-laboratory areas.
• Consider the need for vented chemical storage areas or cabinets for chemicals with low odor thresholds.
• Semi-conductor and other hazardous gases (e.g., silane, hydrogen fluoride, chlorine, etc.) must be placed in vented gas cabinets
• Hoods for perchloric acid require stainless steel construction and a wash-down system and a dedicated, isolated fan.
• Hoods requiring filters (such as those for some radioisotopes or biological materials) should be designed and located such that filters may be accessed and changed easily.
• Provisions should be made for local exhaust of instruments, gas cabinets, vented storage cabinets or other operations requiring local ventilation.
• Single vertical sliding sashes are preferred over horizontal or split sashes.
• Debris screens should be placed in the ductwork leading from the hood.

Emergency Equipment

• Laboratories using hazardous materials must have an eyewash and safety shower within 100 feet or 10 seconds travel time from the chemical use areas.
• Drench hoses support, but do not replace, safety showers and eyewashes.
• Eyewashes and safety showers should have plumbed drains.
• Eyewashes and safety showers should be standardized at least within a laboratory building.
• Flooring under safety showers should be slip-resistant.
• Safety showers may have privacy curtains, particularly in large laboratories or teaching laboratories.
• Fire extinguishers, safety showers and eyewashes should be conspicuously labeled, particularly if recessed.
• Fire extinguishers appropriate for the chemicals and equipment in use should be placed near the entrance of each laboratory, mechanical and electrical room.
• Some chemical operations (e.g., distillation hoods) may benefit from hood fire suppression systems.
• Windowless laboratories and environmental chambers should have emergency lighting.
• Alarm enunciator panels should be descriptive of the area where the alarm has activated.

Materials Handling

• Loading docks should be equipped with dockboards and should have enough room to maneuver pallets safely.
• Cryogenic liquid tanks should be placed in such a manner that their controls could not accidentally be manipulated and such that they may be secured to prevent unauthorized access.
• Cryogenic liquid tanks should be placed away from below grade areas where dense vapors may collect and away from glass doors or windows.
• A phone should be placed near any loading area.

Utilities

• Utility shut-off controls should be located outside the laboratory.
• Laboratories should have an abundant number of electrical supply outlets to eliminate the need for extension cords and multi-plug adapters.
• Electrical panels should be placed in an accessible area not likely to be obstructed.
• Ground fault circuit interrupters should be installed near sinks and wet areas.
• Environmental chambers where evacuation or other alarms cannot be heard should be equipped with strobe lighting or additional alarms.
• Central vacuum systems should not be used, since they are vulnerable to contamination. Local vacuum pumps are preferable.
• All vacuum lines should have cold traps or filters to prevent contamination.
• Chilled water loops should be available for equipment in need of cooling. Loops help to avoid excessive wastewater.
• Laser laboratories should have an emergency cut-off switch installed near the entrance of the laboratory to turn off the laser remotely. Many lasers require water-cooling systems requiring ground-fault circuit interrupters.

Other

• Laboratories using highly toxic gases should be equipped with alarmed vapor sensors, preferably with automatic shutdown systems.
• Gas lines from highly toxic gases should use coaxial tubing for double containment.
• Animal care and use areas must meet Association for Assessment and Accreditation of Laboratory Animal Care International standards.
• Laboratories classified as Security Protection Level 2 (high value equipment or security-sensitive materials) may require additional security measures.