University of California Berkeley Toxic Gas Program

Transcription

1 University of California Berkeley Toxic Gas Program (covering California Fire Code Regulated Toxic and Highly Toxic Gases and other Health Hazard Compressed Gases) May 2011 Prepared by: EH&S

2 TOXIC GAS PROGRAM TABLE OF CONTENTS Section Title Page Introduction 3 Applicability 3 Definitions 4 Roles/Responsibility 6 Program Requirements 7 Issued By and Next Review Date 17 Attachments 17 Page 2 of 17

3 INTRODUCTION A broad spectrum of toxic and health-hazard compressed gases are used at the UC Berkeley campus. Increased recognition of the hazards associated with the transportation, use, and storage of these gases has prompted a higher level of regulation regarding these activities in all work settings. Because of the health hazard presented by an accidental release of these gases on the UC Berkeley campus, the Laboratory Operations & Safety Committee (LO&SC) has directed the Office of Environment, Health & Safety (EH&S) to create and maintain a Toxic Gas Program covering California Fire Code Regulated Toxic and Highly Toxic Gases and other Health Hazard Compressed Gases, designed to minimize the health hazard. The purpose of this program is to reduce the likelihood of an uncontrolled gas release by establishing minimum standards and uniform procedures for purchasing, handling, use, storage, and disposal of these gases at UC Berkeley facilities. APPLICABILITY This program applies to the purchase, transportation, use, storage, and disposal of California Fire Code (CFC) Regulated Toxic and Highly Toxic Gases and other Health Hazard Compressed Gases used by the faculty, staff, and students of UC Berkeley. The range of gases is outlined in Table 1. Pure Gas LC50 (ppm) CFC Toxic Gas Classes a Table 1. Toxic & Health Hazard Gas Classifications zero to 200 greater than 200 to 1000 greater than 1000 to 2000 greater than 2000 to 3000 Highly Toxic Toxic N/A greater than 3000 to 5000 NFPA Health Hazard Classes b Toxic Gas Ordinance c Footnotes: a California Fire Code (CFC) Highly Toxic and Toxic Gases: CFC Highly Toxic Gases have a median lethal concentration (one-hour rate LC50) in air of 200 parts per million (ppm) by volume or less of gas. CFC Toxic Gases have a LC50 greater than 200 ppm and less than or equal to 2000 ppm. b NFPA Class 4, 3, and 2 Health Hazard Gases: NFPA Class 4 gases have a LC50 for acute inhalation toxicity that is less than or equal to 1000 ppm. NFPA Class 3 gases have a LC50 greater than 1000 ppm, but less than or equal to 3000 ppm. NFPA Class 2 gases have a LC50 greater than 3000 ppm, but less than or equal to 5000 ppm. c Toxig Gas Ordinance (TGO) Class 1: LC50 up to 200ppm; Class II LC ppm; Class III LC ppm, For reference only, UCB is not subject to the TGO. Page 3 of 17

4 The CFC defines and regulates toxic compressed gases and refers to these gases as Highly Toxic and Toxic based on their LC 50 values of ppm, and ppm respectively. Use and storage of CFC regulated Toxic Gases and Highly Toxic Gases requires a detailed evaluation by an EH&S specialist and, if necessary, the Campus Fire Marshal. For gas mixtures, the LC50 should be calculated based on the formula published in the CFC [1/(decimal concentration/lc50)]. CFC regulations also limit the quantities of highly toxic and toxic gases being stored, used or handled. These quantities will be explained in the toxic gas evaluation. If and when exempt quantities are exceeded, there will be a need for air monitoring, alarms, emergency power for ventilation units, automatic gas shut-off, automatic fire detection and automatic fire sprinklers. In general, these stringent requirements apply only in a few isolated locations where highly toxic gases in high concentrations are used; however, these CFC requirements are included in the campus program, and are part of the evaluation process. The campus s program also includes health hazard gases with LC50 of ppm. These gases undergo an evaluation similar to CFC toxic gases. Certain dilute health hazard gases are exempt from this program if the worst case release modeling of an accidental acute release indicates that the gas concentration will not result in an average concentration exceeding any of the following: The Cal/OSHA Ceiling Limit, or twice the Short Term Exposure Limit (STEL) The Threshold Limit Value-ceiling (TLV-C) One half of the concentration established as Immediately Dangerous to Life or Health (IDLH) An example of the worst case release modeling is the entire contents of a cylinder discharging into a room; the average concentration cannot exceed the values described above to be exempt from the toxic gas program. The worst case calculation does not include the beneficial effect of ventilation or restrictive flow orifices. DEFINITIONS Ceiling The Cal/OSHA breathing zone chemical concentration that should not be exceeded at any time for a working exposure. Compressed Gas A material that is shipped in a compressed gas cylinder and acts as a gas upon release at normal temperature and pressure, or is used or handled as a gas. CGA In the United States, valve connections are sometimes referred to as CGA connections', since the Compressed Gas Association (CGA) publishes guidelines on what connections to use for what products (e.g. an argon cylinder will have a CGA 580 connection on the valve). DISS Diameter Index Safety System. DISS is a specific type of cylinder valve connection. DISS outlet valves are generally used with high-purity products, toxics, and corrosives. Valves equipped with DISS outlet assignment provide a metal-to-metal seal that creates low particles, a permeation-free environment, and good leak integrity. Page 4 of 17

5 DOT United States Department of Transportation. Responsible for promulgating regulations controlling the transport of toxic gases. Gas A material which is a gas at 68 F and has a boiling point of 68 F or less. Gas cabinet (or exhausted enclosures/fume hoods) When used with CFC, highly toxic gases must have an inflow velocity of more than 200 feet per minute. Other gases covered by this program require an inflow velocity of more than 100 feet per minute. Health Hazard Gases For the purpose of this program, are gases that may cause significant acute health effects at low concentrations. Health effects may include severe skin or eye irritation, pulmonary edema, neurotoxicity, or other potentially fatal conditions. The criteria used to establish the list for this policy are: (1) A National Fire Protection Association (NFPA) health rating of three or four, which is a LC50 less than 3000 ppm; (2) An NFPA health rating of two with poor physiological warning properties; (3) Pyrophoric (self igniting) characteristics; or (4) Extremely low occupational exposure limits in the absence of an NFPA health rating. Highly Toxic Gas (California Fire Code Regulated) A gas that has a median lethal concentration (LC50) in air of 200 parts per million by volume or less of gas or vapor when administered by continuous inhalation for one hour (or less if death occurs within one hour) to albino rats weighing between 200 g and 300 g (0.44 lb and 0.66 lb) each. IDLH Immediately Dangerous to Life or Health as defined by Cal/OSHA. An atmospheric concentration of any toxic, corrosive, or asphyxiant substance that poses an immediate threat to life or would cause irreversible or delayed adverse health effects or would interfere with an individual's ability to escape from a dangerous atmosphere. Leak Test Testing pressurized apparatus by a reliable method. This may include coating all non-welded joints with a soap solution which is capable of forming bubbles at leak points, a pneumatic leakdown test using accurate gauges, or other effective measures. LVE Locally Ventilated Enclosure. Whenever a toxic or corrosive gas is used outside of an exhausted enclosure and has an increased possibility of a leak (e.g. a threaded connection - to the research equipment) the potential leak connection is enclosed and connected to an exhaust source. Magnehelic A diaphragm-type pressure differential sensor with a direct reading gauge NFPA National Fire Protection Association PEL Permissible Exposure Limit as defined by Cal/OSHA. The maximum concentration of an airborne contaminant to which a worker may be exposed when averaged for an 8-hour shift. RMPP Risk Management and Prevention Program. A Risk Management Prevention Program is required by Cal/EPA to anticipate and prevent circumstances that could result in accidental Page 5 of 17

6 releases of acutely hazardous materials (AHMs) if used in amounts greater than the threshold planning quantity (TPQ). The RMPP includes a hazard and operability study, offsite consequence analysis, and seismic analysis. Presently, the campus does not exceed any RMPP- TPQ, but for some highly toxic gases the limits are quite low (e.g. Nickel carbonyl is one pound). RFO Restricted Flow Orifice. An in-cylinder device that reduces the maximum gas release rate. STEL Short Term Exposure Limit as defined by Cal/OSHA. A maximum time weighted exposure that should not be exceeded for any 15-minute period during a workday. STP Standard Temperature and Pressure. STP corresponds to 273 K (0 Celsius) and 1 atm pressure. STP is often used for measuring gas density and volume. TLV-TWA The threshold limit value time weighted average concentration for a normal 8-hour workday or 40-hour workweek, to which nearly all workers may be repeatedly exposed, day after day, without adverse effect. Toxic Gas (California Fire Code Regulated) A gas with a median lethal concentration (LC50) in air of more than 200 ppm, but not more than 2000 ppm by volume of gas or vapor, when administered by continuous inhalation for one hour (or less if death occurs within one hour) to albino rats weighing between 200 g and 300 g (0.44 lb and 0.66 lb) each. There is an exemption to CFC for dilute toxic gases if: 1/the molar (decimal percent) concentration of toxic component/lc50 of toxic = >2000 ppm (This calculation is for exemption to fire code requirements; the campus program will use volume of gas as described in section above.) Laboratory Operations and Safety Committee ROLES/RESPONSIBILITY Establishes and oversees implementation of the toxic gas program in laboratories Arbitrates appeals of purchase requests disapproved by EH&S Principal Investigator or Gas Use Supervisor Coordinates with EH&S Toxic Gas Program Coordinator Maintains primary responsibility for toxic gas safety in the laboratory Includes written safety procedures in the laboratory Chemical Hygiene Plan Provides and maintains gas safety equipment in good working order Conducts and documents laboratory safety self-assessment inspections at regular intervals Provides documented training to toxic gas users Establishes purchasing specifications (quantity minimization, needed concentrations, etc.) Ensures toxic gas program compliance within the laboratory Page 6 of 17

7 Arranges the return of gas cylinders when gas use is completed Provides updates to EH&S upon any changes to the laboratory chemical inventory Responsible for Risk Management and Prevention Program (RMPP); if required, determines the minimum amount of a toxic gas needed for the research Assures that proper MSDS sheets are available and reviewed Updates the chemical inventory with name and quantity of toxic gas and maintain accuracy of toxic gas information Verifies that toxic gas is ALWAYS stored in properly exhausted enclosures (e.g., gas cabinets or fume hoods or fire code compliant gas storage room) Office of Environment, Health & Safety (EH&S) Assists department and Principal Investigator (PI) in establishing appropriate safety procedures and equipment for the proposed use and degree of hazard Reviews and approves new toxic gas purchases and uses based upon potential hazards and available hazard controls Prepares minimum conditions of safe use of toxic gas Conducts follow up evaluations of toxic gas installations to ensure that requirements of the Toxic Gas Program have been implemented Determines health hazard classifications for previously unlisted gases, including: acute and chronic toxicity, carcinogenicity, flammability, pyrophoricity, and corrosivity Provides gas release modeling data as necessary, determines if low concentrations or small quantities are exempt from toxic gas program requirements. Maintains and updates the Toxic Gas Program Notifies the department and PI if gas type and amount requested may necessitate a Risk Management and Prevention Program (RMPP) Assists the PI in developing an RMPP and acts as liaison to regulatory agencies Verifies that the California Fire Code requirements for Highly Toxic and Toxic gas are met; where required controls are not available by the Campus building mechanical and electrical systems, limit ordering to the exempt amounts (by concentration and quantity) Departmental Purchasing Unit, Material Management Reviews all compressed gas requests and ensures that toxic gas requests are approved by EH&S prior to placing orders Informs users of policies regarding toxic gas purchasing (see diagram below) PROGRAM REQUIREMENTS/PROCEDURES PURCHASE APPROVAL PROCESS The gas purchase approval process applies to new uses of all gases defined by this program, as well as changes in volume, use, or location for existing uses. The purchasing process is diagrammed in Figure 1. Renewal purchase requests for gas uses that have been previously approved will be expedited through the purchase process. Page 7 of 17

8 The gas user shall first present a purchase request to their departmental purchasing unit and the gas purchaser/user should identify the compressed gas as a gas covered by the campus toxic gas program. The purchasing unit shall then forward information about the request to the Office of Environment, Health & Safety (EH&S) or ask the purchaser to contact EH&S. EH&S will then contact the gas user to gather information to perform the evaluation and discuss safety issues related to the proposed use. An evaluation of a gas purchase request may involve interviewing the gas user or laboratory safety officer, a laboratory visit, modeling of a laboratory gas release, and/or specific recommendations for gas use safety. The criterion for gas purchase approval is the ability to provide a safe working environment and advance provision for proper handling and disposal. Emergency procedures and accidental release scenarios may be part of the evaluation. If the proposed gas purchase will result in a change in the laboratory's Occupancy Use Classification (as defined in the California Building Code), the current editions of the California Building Code and the California Fire Code requirements will apply. If these requirements are not feasible, the PI will work with EH&S to propose alternate means of providing adequate protection for review and approval by the Campus Fire Marshal. In existing laboratories where the purchase will not result in an Occupancy Use Classification change, EH&S will ensure that currently enforced safety and environmental regulations are properly addressed, and may require additional precautionary measures applicable to the proposed use. Upon EH&S s approval of the gas purchase, notification will be sent to the departmental purchasing unit and to the gas user. The purchasing unit will then proceed with the gas ordering process. If the gas use plans are not approved, EH&S will notify the gas user of specific deficiencies and will work with them to implement any needed safety modifications. Unapproved purchase requests that cannot be resolved may be appealed to the Laboratory Operations & Safety Committee (LO&SC) Chair for an acceptable resolution. If the gas is not in the laboratory's current chemical inventory, the user shall amend the chemical inventory within fifteen (15) days of receiving the gas. As part of the ordering process, the gas user is responsible for obtaining vendor information regarding volume of gas at STP, chemical compatibility for process equipment, manifold specifications, and the availability of restricted flow orifices. This information should be shared with EH&S during the evaluation process. Restricted Flow Orifices (RFOs) should be used wherever possible unless not feasible, such as when corrosive gases are used. Page 8 of 17

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10 TRANSPORTING GASES COVERED BY THE PROGRAM TRANSPORT FROM OFF-CAMPUS SUPPLIER All commercial vendors and university employees shall comply with DOT regulations, where applicable, regarding the transport of program gases. Questions regarding the transportation of gases should be directed to the Office of Environment, Health & Safety (EH&S) at or ON-CAMPUS TRANSPORT All transport of gases covered by this program between on-campus locations must be conducted as follows: Gas cylinders must be secured to the transport vehicle (cart, motor vehicle, hand truck, etc.) Cylinders must be continuously attended during transport. Cylinders should not be left indoors unattended outside of ventilated control or laboratory space where it will be used. Cylinders must be clearly labeled with content and hazard information Cylinder caps must be in place An open truck with separate cab should be used to transport toxic and highly toxic gas. Leak check before transporting. If enclosed truck is used, ventilate before entering in case of fugitive emissions. Do not transport gases covered by this program inside a passenger car. These requirements apply to all gas containers, including empty and partially full cylinders. STORAGE, HANDLING AND USE REQUIREMENTS Receiving Upon receipt of a toxic gas, the cylinder shall be temporarily stored in a well-ventilated area that is attended or locked at all times. All cylinders shall be immediately leak tested with a leak indicating solution and must be clearly labeled with content and hazard information. Temporary storage locations shall have appropriate signage in place. Cylinders must be seismically secured at all locations with chains at two contact points on the cylinder body, using unistruts or an equivalent. Seismic securing should prevent cylinders from rolling, shifting, or falling. The valve safety cap should be in place to protect the valve. Storage Indoor storage of all gas cylinders in this program shall be in a mechanically ventilated, lockable area. Examples of mechanical ventilated areas include exhausted gas cabinets, fume hoods, and Page 10 of 17

11 special fire code compliant gas storage rooms. Rooms containing toxic gas cylinders shall be locked when not occupied by authorized persons. Should a gas cylinder be found to be missing it shall be reported to campus police and EH&S immediately. All cylinders and gas cabinets must be clearly labeled with content and hazard information. Cylinders shall be secured at all locations with noncombustible chains (two contact points), using unistruts or an equivalent for large cylinders. Small lecture bottles must be secured to a stable surface so that the valve is protected. Outdoor storage is allowed on a short term basis in a secure area at least 75 feet from an exterior door, window, or ventilation air intake. If a toxic gas cylinder is no longer needed, it should be returned to the vendor or disposed of as hazardous waste. Gas Regulators and Lines All regulators, valves, and lines must be chemically compatible with the gases being used. Compatibility can be determined by contacting the gas vendor. Pressurized Gas regulator/line systems must be leak tested immediately after assembly and before each use with toxic gas. The gas supply lines must be designed with minimum amount of fittings. In some cases, single piping or welded joint lines may be required. Regulators shall be compatible with the size and type of gas cylinder being used and rated for full cylinder pressure. Caution is necessary with compatibility of corrosive gases. The program may require that Restrictive Flow Orifices (RFO) be installed inside the cylinder by the vendor. Cylinder and Reaction Vessel/Chamber Enclosure All program gas cylinders shall be kept in gas cabinets or ventilated enclosures during storage and use as determined during the evaluation. These cabinets may need to be equipped with an automatic sprinkler. Air-flow velocities at the work opening into the gas cabinet must have a face velocity of not less than 200 fpm for highly toxic and toxic (if over exempt quantity) gases with a minimum of 150 fpm at any point of the access port or window. Where regular access is needed, small access doors can be used to minimize exhaust volume and provide high inflow velocity. Reaction vessels and chambers should be inside exhausted enclosures like fume hoods. In some cases the research equipment cannot be located inside the fume hood. In these cases, additional engineering controls will be necessary such as RFOs, chemical sensing of the air (with alarms), automatic shut-offs, and administrative controls. All program gases must be in a room where the exhaust ventilation is not recirculated. There must be a ventilation rate of at least 1 cfm/square foot of the room area, and negative ventilation pressure relative to neighboring occupied spaces (e.g., hallways, offices, classrooms and neighboring laboratories). Page 11 of 17

12 Purge Vents and Exhaust Lines All lines or ducts carrying purged or exhausted emissions of gases must be connected to a mechanical exhaust system that discharges to a safe location (i.e., presents no potential for reentrainment into any building supply air intake or occupied area). Construction of the exhaust ducts shall be chemically resistant to degradation by the gas in use. Significant emissions of corrosive or toxic gases require an emission control device (e.g., scrubber, flare device, adsorbent) before the purged gas can be vented into the exhaust duct system. Significant emissions are defined as duct concentrations that result in duct corrosion or acute health risk to persons exposed near exhaust fan stacks as determined by release modeling. When CFC Regulated toxic and highly toxic gases are emitted from exhaust systems at concentrations which could pose health risks to rooftop workers, locked gates, doors, or other means shall be used to prevent worker access to stack discharge areas. Warning signs must be conspicuously placed. Ventilation Monitoring A ventilation monitor is required on each fume hood or gas cabinet in which toxic gases are used and stored. Acceptable monitors include audible and visual alarms, magnehelic gauge, or other devices which indicate that the enclosure is properly ventilated. Airflow meters should be clearly marked to indicate satisfactory ventilation rates. Gases covered by this program cannot be used if the ventilation rate is not satisfactory. Ventilation monitoring interlocked with automatic gas shutdown may also be required for highly toxic gases, or for unattended batch processes Automatic Fire Detection Systems An approved automatic fire detection system shall be installed in rooms or areas where highly toxic compressed gases are stored or used. Activation of the detection system shall sound a local alarm. Empty Cylinder Disposal All empty gas cylinders shall be labeled as empty; however, empty cylinders may still contain some toxic gas, so must remain in exhausted enclosures or fire code compliant gas storage rooms. Depleted gas cylinders should be returnable to the vendor according to their guidelines. The purchase of any gases that will not be completely used in the course of research must be approved by the vendor for return, or by EH&S for disposal as hazardous waste. Disposal of these gas cylinders even when empty may entail extraordinary costs; therefore, these program gases should be purchased only from vendors who will accept returns. Some small cylinders lecture bottles are not returnable. If only a small quantity of gas is needed, an assessment should be made of the smallest returnable cylinder. At the end of the project it is recommended that the remaining gas be returned to the vendor. Page 12 of 17

13 Gas Monitors Continuous electronic gas monitors with alarms are recommended wherever toxic gas is used or stored. The requirement for a monitoring system will be decided on a case by case basis and will be required more commonly for continuous operations and long term research situations, if the gas is being used outside of an exhausted enclosure, or if the gas has poor warning properties (e.g. olfactory threshold greater than the PEL). Some gases with poor warning properties are identified in Table 2. If monitoring occupied spaces, gas monitoring equipment must be able to detect concentrations at or below the PEL or ceiling limit. A gas detection system is not required for toxic gases when the physiological warning threshold level for the gas is at a level below the accepted PEL for the gas. The PI is responsible for ensuring that the monitor is maintained and sensors calibrated at a frequency recommended by the manufacturer. EH&S may require periodic calibration or demonstrations that the monitor is working properly. Alarm Locations for CFC Regulated Gases All gas monitoring systems should have: Audible and visible alarms in the following locations: gas supply location, gas use or operator room, and outside the gas use room (e.g. corridor) An alarm status and gas concentration readout panel located outside the gas use room Local audible and visual alarms specific and distinct from fire alarm bells and signs to indicate the alarm's meaning and required personnel action The gas monitoring panel shall send a signal to the UCPD or other continuously attended location The toxic gas alarm level set-point at the PEL or Threshold Limit Value Upon detection, the gas supply shall be shutoff Power and Control For CFC regulated gases, monitors and alarms should be connected to an emergency power source. In the event of a power failure, the detection system should continue to operate without interruption, or gas systems should automatically shut down at the source. Power connections, control switches, and adjustments that affect the detection system operation should be protected from direct access by locks on the enclosures. Page 13 of 17

14 Toxic Gas Name NFPA Health Hazard Rating Pyrophoric Properties UFC Toxic UFC Highly Toxic Corrosive Warning Properties Exposure Limits Stainless Steel Monel Brass Aluminum Zinc Nickel Copper RMPP TPQ (Pounds) LC 50 Values (ppm) allene 3 n n n n unknown ND c u u c c c u N/A ND ammonia 3 n n n y good 35 ppm (S) c c nc c n u n arsenic pentafluoride 4 n y y unknown 5 mg/m3 (I) u u u u u u u N/A ND arsine 4 n y y n poor 3 ppm (I) c c c u u u u boron trichloride 3 n n n y good 100 ppm (I) c c c u u u c boron trifluoride 3 n y n y good 3 ppm (C) c c c c u u c bromine pentafluoride 3 n y y y poor 0.1 ppm P c c c u u c c N/A 50 bromine trifluoride 4 n y y y unknown 5 ppm (S) c c c u u c c N/A 50 1, 3 butadiene 4 n n n n good 10 ppm (S) c c c c c u c N/A carbon tetrafluoride 3 n n n n unknown ND c n c c c c c N/A carbon monoxide 2 n n n n none 35 ppm P c c c c c u c N/A 3325 carbonyl fluoride 3 n y n n unknown 5 ppm (S) u c u u u u c N/A 360 carbonyl sulfide 3 n y n y good ND c c c c u u c N/A 1070 chlorine 3 n y n y good 1 ppm (S) c c nc nc nc u nc chlorine trifluoride 4 n y n y poor 0.1 ppm (C) u u u u u u u N/A 229 cyanogen 4 n y n y poor 10 ppm (P) c c u u u u u N/A 350 cyanogen chloride 4 n y y n poor 0.3 ppm (C) u u u u u u u N/A ND diborane 4 y y y n poor 0.1 ppm (P) c u u c u u u dichlorosilane 3 n y n y unknown ND c c u u u u u N/A 215 Page 14 of 17

15 Toxic Gas Name NFPA Health Rating Pyrophoric Properties CFC Toxic or Highly Toxic CFC HighlyToxic Corrosive Warning Properties Exposure Limits Stainless Steel Monel Brass Aluminum Zinc Nickel Copper RMPP TPQ (Pounds) LC 50 Values (ppm) dimethylamine 3 n n n n unknown 5ppm (P) c u n u n u n N/A 4540 fluorine 4 n y y y good 25 ppm (I) c c u c u u c germanium tetrahydride 4 n y n n unknown 0.2 ppm P c u c c u u c N/A 442 hydrogen bromide 3 n n n n good 30 ppm (I) c c nc u nc u nc N/A 2858 hydrogen chloride 3 n n n y good 50 ppm (I) c c nc u nc u nc hydrogen cyanide 4 n y y n good 50 ppm (I) c u u u u u u N/A 160 hydrogen fluoride 3 n y n y good 30 ppm (I) c c u u u u u hydrogen selenide 4 n y n poor 1 ppm (I) c u c c u u u 10 ND hydrogen sulfide 3 n y n n good 100 ppm (I) c c u c u u u methyl bromide 3 n y n y poor 250 ppm (I) c u c nc u u c 1, methyl chloride 2 n n n n poor 100 ppm (P) c c c nc nc u c N/A methylsilane 3 n n n n unknown ND u u u u u u u N/A ND monomethylamine 3 n y n n unknown ND c u n n n n n N/A 448 nickel carbonyl 4 n n y n unknown ND c u c u u u c 1 35 nitric oxide 3 n n y n unknown 100 ppm (I) c c c c u u c nitrogen dioxide 4 n y y y good 1 ppm (C) c c u c u u u nitrogen trifluoride 3 n y n y poor 5 ppm (C) u u u u u u u N/A 2000 phosgene 4 n y y n poor 2 ppm (I) c c u u u u nc Page 15 of 17

16 Toxic Gas Name NFPA Health Rating Pyrophoric Properties UFC Toxic or Highly Toxic Highly Toxic Corrosive Warning Properties Exposure Limits Stainless Steel Monel Brass Aluminum Zinc Nickel Copper RMPP TPQ (Pounds) LC 50 Values (ppm) phosphine 4 y y y n good 50 ppm (I) c c u u u u u phosphorus 3 n y y unknown ND c c u u u u u N/A ND pentafluoride phosphorus trichloride 3 n y y y unknown 0.5 ppm (S) u u u u u u u phosphorous 3 n y n unknown ND u u u u u u u N/A ND trifluoride silicon tetrahydride 2 y n n n unknown ND c c c c u u c N/A 9600 silicone tetrafluoride 3 n y n n poor ND c c c c u u c N/A 2272 stibine 4 n y y n good 5 ppm (I) u u u u u u u N/A 100 sulfur tetrafluoride 4 n y y y unknown ND c u c c u u c sulfuryl fluoride 3 n y n n poor 200 ppm (I) c u u c u u c N/A 991 tungsten hexafluoride 3 n y y y unknown 3 mg/m3 (S) u u u u u u u N/A 118 vinyl chloride 4 n y n n poor 5 ppm (C) c u u u u u nc N/A 390 Material Compatibility: c=compatible, nc =not compatible, u=unknown Exposure Limit: C=Ceiling, I=IDLH, P=PEL or TLV, S=STEL, ND= not determined N/A = not applicable Page 16 of 17