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What safety professionals should know abut IMC 510
Laboratory Health & Safety
What safety professionals should know abut IMC 510
T
he International Code Council (ICC) was established in 1994 as a non-profit organization to develop a single set of comprehensive national construction codes. The Building Officials & Code Administrators (BOCA), the International Conference of Building Officials (ICBO), and the Southern Building Code Congress International (SBCCI) started the ICC. Section 510.2 of the code is entitled, ‘‘Hazardous Exhaust Systems,’’ and is of concern to laboratory and chemical safety professionals. This Section requires that hazardous exhaust systems be provided wherever there are operations involving the handling or processing of hazardous materials. Hazardous materials are defined by the Code as those substances that meet one of the following conditions: In-duct concentrations exceed 25% of the Lower Flammability Limit (LFL/LEL) at room temperature Materials with an NFPA health hazard rating of 4, e.g., phenol, at any concentration Materials with an NFPA health hazard rating of 1, 2, or 3, present in concentrations exceeding 1% of the median lethal concentration for acute inhalation toxicity. If any of the above conditions exist, the hazardous exhaust system must: Have an in-duct fire suppression system (sprinkler) unless duct materials are nonflammable and non-combustible Must have an independent exhaust system, that can not share common shafts with other duct systems unless they are in the same fire area (essentially eliminates hood manifolding). These requirements present difficulties for research laboratories for several reasons. Most research labs handle small quantities of a large variety of chemicals for relatively short time periods. Properly functioning and maintained hood ventilation systems rapidly dilute the
1074-9098/03/$30.00 doi:10.1016/S1074-9098(03)00036-4
chemical concentrations being used. Hence, the potential for creating a concentration in the duct capable of causing a fire is small and does not warrant a sprinkler system in the ductwork. In addition, hood sprinkler systems could create additional danger by allowing an uncontrolled flow of water to enter the hood and wash the contents of the hood onto the laboratory floor. The danger is compounded if water reactive chemicals are in the hood. The chemical often mentioned with respect to IMC 510 is phenol, which has an NFPA health hazard rating of 4. Phenol is a common laboratory chemical typically used in small quantities in many analytical and biomedical laboratories. The dilution effect in properly functioning hoods is more than adequate to generate little vapor and minimal risk. Implementation of a dedicated exhaust system as required by IMC 510 is a substantial burden to laboratories for several reasons. A manifolded hood system essentially eliminates the risk in handling most common research lab chemicals and procedures by dilution. Manifolded systems enable a redundant fan system to be used that can take over automatically in the event of a fan failure, or during maintenance. Integrating back-up emergency power for ventilation is also easier and less expensive in a manifold system expensive than for a dedicated system. Operating one six-foot hood 24/7 costs about $5,000/ year, not including maintenance costs. This cost is greatly reduced and safety is significantly increased when a manifolded system is used. Instituting a thoughtless, knee-jerk response to a regulation is never a good idea. As safety professionals we always need to consider all aspects of all regulations and requirements. During any new construction or renovation never hesitate to meet with local building code and fire officials to logically discuss you own unique requirements and concerns. For additional information refer to the article by J. Koenigsberg (Chem. Health Safe. 2003, 10(1), 35).
ß Division of Chemical Health and Safety of the American Chemical Society Elsevier Science Inc. All rights reserved.
33
What safety professionals should know abut IMC 510
T
he International Code Council (ICC) was established in 1994 as a non-profit organization to develop a single set of comprehensive national construction codes. The Building Officials & Code Administrators (BOCA), the International Conference of Building Officials (ICBO), and the Southern Building Code Congress International (SBCCI) started the ICC. Section 510.2 of the code is entitled, ‘‘Hazardous Exhaust Systems,’’ and is of concern to laboratory and chemical safety professionals. This Section requires that hazardous exhaust systems be provided wherever there are operations involving the handling or processing of hazardous materials. Hazardous materials are defined by the Code as those substances that meet one of the following conditions: In-duct concentrations exceed 25% of the Lower Flammability Limit (LFL/LEL) at room temperature Materials with an NFPA health hazard rating of 4, e.g., phenol, at any concentration Materials with an NFPA health hazard rating of 1, 2, or 3, present in concentrations exceeding 1% of the median lethal concentration for acute inhalation toxicity. If any of the above conditions exist, the hazardous exhaust system must: Have an in-duct fire suppression system (sprinkler) unless duct materials are nonflammable and non-combustible Must have an independent exhaust system, that can not share common shafts with other duct systems unless they are in the same fire area (essentially eliminates hood manifolding). These requirements present difficulties for research laboratories for several reasons. Most research labs handle small quantities of a large variety of chemicals for relatively short time periods. Properly functioning and maintained hood ventilation systems rapidly dilute the
1074-9098/03/$30.00 doi:10.1016/S1074-9098(03)00036-4
chemical concentrations being used. Hence, the potential for creating a concentration in the duct capable of causing a fire is small and does not warrant a sprinkler system in the ductwork. In addition, hood sprinkler systems could create additional danger by allowing an uncontrolled flow of water to enter the hood and wash the contents of the hood onto the laboratory floor. The danger is compounded if water reactive chemicals are in the hood. The chemical often mentioned with respect to IMC 510 is phenol, which has an NFPA health hazard rating of 4. Phenol is a common laboratory chemical typically used in small quantities in many analytical and biomedical laboratories. The dilution effect in properly functioning hoods is more than adequate to generate little vapor and minimal risk. Implementation of a dedicated exhaust system as required by IMC 510 is a substantial burden to laboratories for several reasons. A manifolded hood system essentially eliminates the risk in handling most common research lab chemicals and procedures by dilution. Manifolded systems enable a redundant fan system to be used that can take over automatically in the event of a fan failure, or during maintenance. Integrating back-up emergency power for ventilation is also easier and less expensive in a manifold system expensive than for a dedicated system. Operating one six-foot hood 24/7 costs about $5,000/ year, not including maintenance costs. This cost is greatly reduced and safety is significantly increased when a manifolded system is used. Instituting a thoughtless, knee-jerk response to a regulation is never a good idea. As safety professionals we always need to consider all aspects of all regulations and requirements. During any new construction or renovation never hesitate to meet with local building code and fire officials to logically discuss you own unique requirements and concerns. For additional information refer to the article by J. Koenigsberg (Chem. Health Safe. 2003, 10(1), 35).
ß Division of Chemical Health and Safety of the American Chemical Society Elsevier Science Inc. All rights reserved.
33