Overview

Engineering controls are considered the first line of defense in the laboratory for the reduction or elimination of potential exposure to hazardous chemicals. Examples of engineering controls used in laboratories at KAUST include dilution ventilation, local exhaust ventilation, chemical fume hoods, glove boxes, safety shields, and proper storage facilities.

Chemical Fume Hoods

Chemical fume hoods are installed in laboratories to protect individuals from airborne substances (gases, vapors, mists, fumes) generated by laboratory experiments. However, simply conducting these experiments in the fume hood does not guarantee adequate protection. The fume hood must be used properly.

These guidelines will help you optimize the effectiveness of your fume hood.


  • Check the airflow indicator prior to use to ensure the fume hood is drawing air. Many of the hoods at KAUST are equipped with airflow monitors that display a digital readout of the face velocity and/or beep or light up when the velocity is too low. If an airflow monitor is not installed, test the hood airflow with a piece of light material (such as a tissue or chemwipe) held to the bottom of the sash. The material will deflect inward if the hood is drawing air.
  • Minimize the number of objects stored in the hood – keep at least 50% of the working surface clear, if possible.
  • Always place containers and equipment at least 15 centimeters (6 inches) into the hood from the face.
  • Always place containers and equipment at least 15 centimeters (6 inches) into the hood from the face.


  • Place containers and equipment toward the sides of the hood to reduce obstruction of the exhaust slots.
  • If possible, elevate equipment and containers 4 to 8 centimeters (two to three inches) above the working surface using perforated or slotted shelving to minimize disruption to the airflow.
  • When working in a fume hood, keep doors closed within the lab and minimize traffic in front of the hood. Minimize rapid movements while working in the hood, including opening and closing the sash. All of these precautions will help to prevent air currents from forming, which can result in hazardous vapors being pulled out of the hood and into the laboratory personnelʼs breathing zone.
  • When working in a fume hood, keep doors closed within the lab and minimize traffic in front of the hood. Minimize rapid movements while working in the hood, including opening and closing the sash. All of these precautions will help to prevent air currents from forming, which can result in hazardous vapors being pulled out of the hood and into the laboratory personnelʼs breathing zone.
  • Always work with the fume hood sash as low as possible and always keep your fume hood sash closed when you are not working in it. This offers better protection against splashes and explosions and saves a significant amount of energy and electricity.


  • Do not use fume hoods to evaporate hazardous waste. Evaporating hazardous waste as a means of disposal is prohibited at KAUST. When
  • Pouring flammable liquids, always make sure both containers are electrically interconnected to each other by bonding and grounding in order to prevent the generation of static electricity - which can cause the flammable liquid to ignite.
  • As with any work involving chemicals, always practice good housekeeping and clean up all chemical spills immediately. Be sure to wash both the working surface and hood sash frequently and always maintain a clean and dry work surface that is free of clutter.
  • Always report any malfunctioning fume hoods by submitting a ticket via the Help Desk to 959 immediately. If the fume hood is not working properly, then let other people in the lab know by hanging up a Do Not Use sign on the hood.

Be aware that the use of heated perchloric acid requires a special perchloric acid fume hood with a wash down function. DO NOT use heated perchloric acid in a regular fume hood. If heated perchloric acid is used in a regular fume hood (without a wash down function), shock sensitive metallic perchlorate crystals can form inside the duct work, and could result in causing an explosion during maintenance work on the ventilation system. If you are considering working with heated perchloric acid, then please contact HSE at hse@KAUST.edu.sa for more information.

Fume hoods must be inspected and tested annually to ensure that they are working properly. During the inspection, the air flow face velocity is measured and compared against recommended standards, and a smoke test is conducted to ensure adequate capture and containment. The fume hood is also checked for potential air flow interferences including excessive storage in the fume hood, blockage of the exhaust slots, HVAC vents located near the face of the hood, and location of the fume hood in a heavy traffic area. Fume hood inspections are conducted in accordance with the following standards:
ANSI/ASHRAE 110-1995, “Method of Testing Performance of Laboratory Fume Hoods”
Many of the fume hoods at KAUST are equipped with monitors that display a digital readout of the velocity of air being drawn into the hood. The monitor will alarm when airflows are too low or too high. Do not use the fume hood unless it is operating properly.
If you suspect your fume hood is not functioning properly, alert others by placing a sign that reads “Do Not Use” and report it to the Help Desk at 959 immediately.

Lab Ventilation

Lab Ventilation

The laboratories at KAUST are provided with general ventilation adequate for comfort and sufficient to supply air for chemical fume hoods and other local ventilation devices. Because the general air supply is not adequate for manipulating hazardous materials on an open lab bench, volatile or toxic chemicals shall be handled in a chemical fume hood or other appropriate containment device.

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Toxic Gas Management

The TGM system is a sophisticated system that detects the presence of toxic and flammable gases and controls relevant actions such as the shutdown of gases from the gas delivery system, the shutdown of research tools, the activation of alarms and the activation of the emergency notification process. The need for gas monitors, as well as the number and locations of the sensors, shall be determined by the KAUST Research Safety Team in coordination with the KAUST Academic Projects Team based on hazard properties of the gas, possible worst-case release rates, size, and ventilation rate of the affected areas, as well as other risk factors. For system maintenance, sensor calibrations and facilities-related questions please contact: fmcallcenter@KAUST.edu.sa

For more information please check:
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Toxic Gas Management

Biosafety Cabinets and Laminar Flow Hoods

Biological Safety Cabinets

Biological Safety Cabinets

Biological safety cabinet (BSC) is an engineering device that reduce the risk of working with biohazardous and infectious microorganisms. BSCs of Class II and Class III are also used for maintaining aseptic conditions when working with cell cultures. BSCs utilize High Efficiency Particulate Air (HEPA) filters in the supply air and exhaust systems to create a nearly sterile work environment. Thus, BSCs provide personnel, environmental, and product protection when appropriate practices and procedures are followed.
There is a training that is recommended if you want to know more about biosafety cabinets. Biological Safety Cabinet Training

Laminar Flow Hoods (Clean Benches)

Laminar Flow Hoods (Clean Benches)

Laminar flow hood (LFH), also called clean bench, protects the product from airborne contamination, but does not protect the operator. Because of the risk to personnel, work with hazardous material in a laminar flow clean bench is not permitted. Use of clean benches should be limited to the preparation of sterile media, the assembly of sterile components into complete units (e.g., membrane filters), the examination of sterilized equipment and materials for possible contamination, and similar operations. BSCs and LFHs are certified on an annual basis. This is coordinated by HSE. Contact HSE if you have any of the following: New or moving a BSC or LFH. General questions about BSCs or LFHs. Issues you are having with your BSC or LFH.

Glove Boxes

Glove boxes are sealed enclosures designed to protect the user, the process, or both. They are usually equipped with at least one pair of gloves attached to the enclosure. The user manipulates the materials inside using the gloves. Typically, a glove box has an antechamber that is used to take materials in and out of the box. Gloves should be regularly inspected for cuts, tears, cracking and pinhole leaks. If defects are found, the gloves should be replaced. Note that there are many different types of glove box gloves that vary in thickness, material, size, etc. Choose the correct one for the glove box and application.
Regular maintenance and inspection is essential to ensure that a glove box is adequately protecting the user, the environment, and the experiment.
Routine maintenance procedures and the frequency of inspection (or certification) should follow the manufacturers and regulatory recommendations.

Glove Boxes

Ductless Fume Hoods
and Weigh Stations

Ductless fume hoods and weigh stations utilize filter technology to remove chemical contaminants before discharging exhausted air back into the laboratory. Care must be taken to ensure that the unit has the appropriate filter for the intended application. Some units, intended for weighing powders only, afford no protection against chemical gases or vapors.
Contact HSE at hse@kaust.edu.sa if you have questions about the types of chemicals that can be used in ductless hoods and weigh stations.