The University of Arizona

Risk Management Services

Laboratory Chemical Safety Manual

Table of Contents

February 2012, version 1.3
This document replaces all previous versions of the UA Chemical Hygiene Plan

General Laboratory Chemical Safety Practices

1. Standard Operating Procedures

It is impossible to design a set of rules that will cover all possible chemical or laboratory hazards and consequences. The general prudent practice guidelines described below have been shown through experience to be useful for avoiding accidents or reducing injuries associated with the laboratory use of hazardous chemicals. They have been prepared to provide logical means of identifying and controlling hazards associated with the use of hazardous chemicals at the University of Arizona, from conceptual use stages to the time of their disposal. They are not meant to be an all inclusive list of rules and procedures. Readers will be required to look further for information specific to their activities and develop their own laboratory or operation-specific safety protocols.

1.1) Planning Chemical Use: Before beginning an operation or performing an experiment, ask "What would happen if…?" (PDF format) and be prepared to prevent such an occurrence or to take proper emergency actions. Answers to this question will require an understanding of the hazards associated with the chemicals and equipment involved (see: Chemical Safety Information - Chemical Hazards Overview).

1.1.1) Research Hazards: All chemicals and the manner in which they are intended to be used must be scrutinized by the user to identify potential hazards before acquiring the material or conducting a procedure - if the material is already in possession (see: Chemical Safety Information - Chemical Hazards Overview), as a resource).

1.1.2) Categorize Laboratory or Request Prior Approval: Based on the chemical hazards review and laboratory safety level descriptions below, the Supervisor must categorize the laboratory as either CSL-1 or CSL-2 and register the lab with the interim Chemical Safety Committee (iCSC) using the Chemical Lab Registration Form, AND approval must be requested for CSL-3 status (see Chemicals/Activities Requiring Prior Approval). The following flow chart will lead Supervisors through this process.

CSL Chart warning labels designated area signs designated area signs toxic chemicals highly toxic chemicals reproductive toxins select carcinogens extremely hazardous chemicals/activities


CSL-3 laboratories are designated by activities on the Extremely Hazardous Chemicals/Activities List (PDF format).


CSL-2 laboratories are labs that use select carcinogens, reproductive toxins, or highly toxic chemicals. This includes chemicals manufactured in the U.S. after 1985 that have any of these words on the label or chemicals that meet the OSHA definition of these hazards (see Chemical Safety Information).


CSL-1 laboratories include all other labs using hazardous chemicals.

1.1.3) Post Laboratory: An appropriate CSL-1 (PDF format) or CSL-2 (PDF format) sign must be posted on the outside of the main door to the laboratory (see: Signs/Posters/Charts). CSL-1 and CSL-2 signs will be provided by Risk Management Services (RMS) after Supervisors electronically register their hazardous chemical use using the Lab Registration Form. Signs for CSL-3 (PDF format) laboratories will be provided by RMS upon approval by the interim Chemical Safety Committee (see Chemicals/Activities Requiring Prior Approval). Emergency contact information (PDF format) must be posted on the inside of all doors to the laboratory and near the phone (see Emergency Contact Information Poster). These signs will also be provided by RMS after Supervisors register their hazardous chemical use.

1.1.4) Assure Adequate Hazard Controls and Emergency Equipment: Once the hazards have been identified, commensurate hazard controls and emergency equipment must be planned and acquired or developed to adequately control the hazards to a negligible risk level and to respond to any emergencies which may arise (see Chemical Safety Information - Principles for Controlling Chemical Hazards, for general guidance and Minimum Requirements for Toxic/Corrosive Gas Use (PDF format), for specific guidance, if applicable). The work conducted and its scale must be appropriate to the physical facilities and available engineering controls and emergency equipment. It is the intent of the University to provide and maintain basic engineering hazard controls (e.g. fume hoods) or emergency equipment (e.g. emergency eyewashes, fire extinguishers) for building spaces appropriate to their original intended use. If a specific project necessitates additional engineering controls, specialized maintenance, new safety devices or equipment, the project funding source or its Department/College shall fund the needed improvements. An approved safety shower and eyewash must be provided within the work area for immediate use (within 10-15 seconds of exposure) where eye hazards are present. Squirt bottle eyewashes are not acceptable in areas where corrosive chemicals are used or stored. Sink-mounted eyewashes are available free of charge from RMS for laboratories without eyewashes (contact RMS at 621-1790). An appropriate fire extinguisher must be available (within 75 feet) to areas where flammable or combustible materials are used or stored. A fire alarm and telephone for emergency use must also be nearby (within 50 feet). Chemical storage space adequate to the lab's needs and responsive to the requirements outlined in Chemical Management Best Practices - Storage, must be provided for activities involving chemicals. The funding responsibilities identified in Section apply. A hazard assessment survey must be conducted and documented to assess the need for personal protective equipment (see Personal Protective Equipment and the related PPE Hazard Assessment Certification Form – Word format).

1.2) Chemicals/Activities Requiring Prior Approval: Prior approval from the interim Chemical Safety Committee (iCSC) is required before using any of the following chemicals or conducting any of the following activities, deemed extremely hazardous by the iCSC (see: Extremely Hazardous Chemicals/Activities List – PDF format).

1.2.1) The list of chemicals/activities requiring prior approval includes the following: Chemicals/activities which are difficult to control (e.g., very high vapor pressure or respirable particle size) AND, have lethal potential in one, low level exposure (e.g., extremely low exposure limit or IDLH level). Chemicals/activities which are difficult to control (e.g., very high vapor pressure or respirable particle size) AND, difficult to detect (i.e., poor warning properties) AND, are know to trigger a life-shortening disease condition in one, high level exposure (e.g., known potent reproductive toxins, known potent carcinogens- as defined in Chemical Safety Information - Chemical Hazards Overview). Chemicals/activities that have a significant probability (based on accident history in the literature) to cause a lethal event (e.g., large explosion).

1.2.2) Other activities maybe added to the Extremely Hazardous Chemicals/Activities List by the iCSC, based on inherent hazards of the activity, or upon recommendation of the VP for Research & Graduate Studies, or the Director of RMS.

1.2.3) Prior approval requests must be made by providing additional requested information when registering the laboratory using the Chemical Lab Registration Form. Request will be followed by a laboratory inspection from the Chemical Safety Officers and the request will be reviewed and considered by the interim Chemical Safety Committee (iCSC).

1.2.4) The iCSC will deliberate on all requests and either approve, conditionally approve, or disapprove. Written responses will be provided back to requestors.

1.3) Chemical Acquisition: Hazardous chemical must be acquired according the guidelines described in Chemical Management Best Practices - Chemical Acquisition.

1.4) Labeling/Identification: All hazardous chemicals must be properly labeled at all times, from the time they are brought into University facilities, to the time they are removed for disposal per Chemical Management Best Practices - Labeling/Identification.

1.5) Chemical Inventory: Laboratories must at all times maintain an adequate inventory of the hazardous chemicals in the laboratory according to Chemical Management Best Practices - Chemical Inventory.

1.6) Storage: The storage of hazardous chemicals must be accomplished in a manner that minimizes safety and health hazards to personnel, equipment, buildings, and the environment per Chemical Management Best Practices - Storage.

1.7) Distribution: The method of transportation of hazardous chemicals must reflect the potential danger posed by the specific chemical and shall be done in accordance with Chemical Management Best Practices - Distribution.

1.8) General Hazardous Chemical Use: Each Lab Worker with the training and information provided by his/her supervisor, must develop and implement work habits consistent with this Manual to minimize chemical exposures to his/herselves, others and the environment. Based on the realization that all chemicals inherently present hazards in certain conditions, exposures to all hazardous chemicals must be minimized. The guidelines presented below are general rules for minimizing chemical hazards during their use. They must be followed whenever hazardous chemicals are used.

1.8.1) Be Knowledgeable of the Hazards: Know the physical and health hazards associated with the chemicals you are using or producing or of the procedure you are conducting and the safety rules and procedures that apply (use Chemical Safety Information as a resource). Risk determinations shall be conservative. One should assume that any mixture will be more toxic than the most toxic component and that all chemicals of unknown toxicity are toxic. Chemicals with unknown hazards shall be treated as possessing any of the physical or health hazards described in Chemical Safety Information - Chemical Hazards Overview, unless determined otherwise.

1.8.2) Understand and Use Hazard Controls: Know and use the hazard controls as directed by your supervisor, including all engineering and administrative controls and protective equipment.

1.8.3) Know Emergency Procedures: Know the location of and how to use the emergency equipment in your area (e.g. safety shower and eyewash, fire extinguisher, fire alarm, telephone, etc.), as well as how to obtain additional help in an emergency, and be familiar with the general emergency procedures described in Emergency Procedures, and any laboratory-specific procedures. Access to all safety and emergency equipment (e.g. emergency shower and eyewash, fire extinguishers, fume hoods, etc.), exits, and laboratory or building egress paths, must remain unobstructed at all times.

1.8.4) Avoid Hazardous Chemical Exposures by Any Route Skin contact with hazardous chemicals must be avoided under all circumstances. Do not directly smell or taste hazardous chemicals. Do not eat, drink, smoke, chew gum or tobacco, store food or beverages, or apply cosmetics in areas where hazardous chemicals are used or stored. Do not use glassware, containers, or utensils usually meant for the consumption of food or beverages in laboratory operations. Likewise, do not use items that are normally used for laboratory operations to prepare, consume, or store food or beverages. Do not use mouth suction for pipetting or starting a siphon. Use a fume hood, or other exhausted enclosure, for operations which may result in the release of appreciable amounts of hazardous (as described in Chemical Safety Information - Chemical Hazards Overview) or odorous chemicals. Before using a hood, confirm that the hood has been certified for chemical use (see Section 2.1). Also confirm that the hood is operational before use (e.g. hold a tissue at the face of the fume hood to determine air flow is directed into the hood). Keep materials stored in fume hoods to a minimum and do not allow them to block vents or air flow. Keep chemicals and equipment at least 6 inches inside the face of the hood. Keep the sash closed as far as possible and at least below the maximum marked open position, as indicated on the hood certification sticker (see Work Practices For Chemical Fume Hoods and Proper Sash Position on Air Sentry Fume Hoods – PDF format). Confine long hair and loose clothing. Wash all areas of skin potentially exposed to hazardous chemicals prior to leaving the laboratory and immediately after handling hazardous chemicals. Leave lab coats and other personal protective equipment in the laboratory when you leave. When it comes time to launder lab coats, have them professionally laundered. Do not take them home. If they are potentially contaminated with hazardous chemicals, dispose of them as hazardous waste (see Hazardous Chemical Disposal). Consider using disposable lab coats when working with non-volatile highly toxic chemicals, carcinogens or reproductive hazards (as defined Chemical Safety Information - Chemical Hazards Overview). Contact lenses are permitted in the laboratory provided the supervisor conducts the required hazard assessment survey (see Section, suitable eye and face protection is available and worn, and an emergency eyewash is available. Contact lenses should be removed in a clean environment, at the first sign of eye redness or irritation, following thorough hand washing. Avoid practical jokes or other behavior which might confuse, startle, or distract another person in the laboratory. Keep the work area clean and uncluttered, with chemicals and equipment properly labeled and stored. Clean up the work area upon completion of an operation or at the end of each day. If conducting an unknown reaction, start with small quantities of materials and carefully observe reaction characteristics. Post warning signs in areas or at equipment where special or unusual hazards exist. Be alert to unsafe conditions and see that they are corrected when detected. Pregnant or lactating woman should be especially vigilant in avoiding hazardous chemical exposures. RMS and/or the Teratogen Counseling Office are available for advice. Weigh hazardous chemical powders in a manner that minimizes exposure and contamination (see Minimizing Exposure and Contamination When Weighing Hazardous Chemical Powders – PDF format).

1.9) Flammable Chemicals: In addition to the general hazardous chemical use guidelines described above (see General Hazardous Chemical Use), the following extra guidelines apply to the use of flammable chemicals as defined in Chemical Safety Information - Chemical Hazards Overview.

1.9.1) Flammable chemicals must be handled only in areas free of ignition sources (e.g. open flames, static electricity, burning tobacco, hot surfaces).
1.9.2) Flammable chemicals must never be heated by using an open flame. Preferred heat sources include steam baths, water baths, oil baths, heating mantles, and hot air baths.
1.9.3) When transferring flammable liquids with a flash point below 73oF (23oC) and a boiling point below 100oF (38oC), (e.g. ether, carbon disulfide) in metal equipment, static generated sparks must be avoided by bonding (electrically interconnecting the two containers with a conductive wire) and the use of ground straps (electrically interconnecting one of the containers to a ground with a conductive wire).
1.9.4) An exhaust hood must be used whenever appreciable quantities of flammable chemicals are: transferred from one container to another; allowed to stand in open containers; heated in open containers, or handled in any other way.

1.10) Explosive/Implosive Conditions: In addition to the aforementioned general guidelines regarding hazardous chemical use (see General Hazardous Chemical Use and Flammable Chemicals), the following extra guidelines apply to the use or generation of explosive chemicals (as defined in Chemical Safety Information - Chemical Hazards Overview), or the undertaking of procedures which, because of their reaction rate or their confines, are potentially explosive or implosive:

1.10.1) Designated Area: All storage and work with these substances must be confined to a designated area. A designated area may be the entire laboratory, an area of a laboratory, or a device such as a laboratory fume hood. The designated area should be the smallest practical area for the application so that the scope of any potential accident is limited. To ensure that all persons with access are aware of the hazardous chemicals being used or procedures being conducted and the necessary precautions, the designated area shall be conspicuously posted with warning and restricted access signs (available in Designated Area Sign – PDF format).

1.10.2) Personal Protective Apparel and Devices: When handling explosive compounds or conducting potentially explosive experiments, a lab coat, gloves, and chemical splash goggles must be worn at all times. Barriers such as shields, barricades, and guards must be used to protect personnel and equipment from injury and damage whenever reactions are in progress or whenever materials are being temporarily stored. The barrier shall completely surround the hazardous area. If at all possible, activities with these substances shall be conducted in a fume hood with the sash lowered to form a shield. If the size of the experimental arrangement does not permit it to occur in a fume hood and it must be moved out into the lab, a 0.25 inch (0.625 cm) thick acrylic shield or equivalent shield shall be used. Heavy duty, flock-lined gloves and a face shield with a throat protector must be worn whenever it is necessary to reach behind a shielded area, move shields aside, or handle or transport explosive compounds.

1.10.3) Reaction Operations: All controls for heating and stirring equipment must be operable from behind the shielded area. Vacuum pumps potentially exposed to highly reactive or explosive gases or vapors must have their oil changed at least once a month and sooner if it is known that the oil has been exposed. All pumps shall either be vented into a hood or trapped. When working with shock or friction-sensitive materials, ground glass fixtures shall be substituted with Teflon or Teflon-coated apparatus. There must be two people present in the area at all times when these operations are used. Contingency plans (i.e., a written plan of what to do if things go wrong), equipment, and materials to minimize exposures of people and property in case of accident must be available.

1.11) Carcinogens, Reproductive Toxins, or Highly Toxic Chemicals: In addition to the aforementioned guidelines regarding hazardous chemical use (see General Hazardous Chemical Use, Flammable Chemicals and Explosive/Implosive Conditions), the following extra guidelines apply the use or generation of chemicals which are known to be carcinogens, reproductive toxins, and highly toxic chemicals as defined in Chemical Safety Information - Chemical Hazards Overview.

1.11.1) Designated Area: All storage and work with these hazardous chemicals must be confined to a designated area as described in Section 1.10.1. Designated area size limitations and signage requirements described in Section 1.10.1 shall also be adhered to.

1.11.2) Containment: Procedures involving volatile chemicals and those operations involving solid and liquid chemicals which may result in the generation of aerosols, must be conducted in some type of containment device such as a fume hood, glove box, or glove bag or captured or scavenged at the source by the means of some type of local exhaust system. Fume hoods shall be certified for hazardous chemical use (see PART 2 - Section 2.1). For a negative-pressure glove box or glove bag, ventilation rates must be at least 2 volume changes/hour and at a pressure of at least 0.5 inches of water gauge. For a positive pressure glove box, thoroughly test for leaks before each use. Other types of local exhaust systems used to capture or scavenge air contaminants must be evaluated and approved by RMS on a case by case basis through the use of air monitoring and qualitative and quantitative air flow measurements. Gases, vapors, and aerosols discharged from experiments involving these hazardous chemicals must be trapped or condensed to avoid contaminating vacuum pumps or discharging substantial quantities to fume hood exhaust air. All pumps must be vented into a hood. Work surfaces which may be accidentally contaminated by these hazardous chemicals must be fitted with removable liners of absorbent plastic-backed paper (available from Campus Stores). Breakable containers and apparatus containing liquid or solid chemicals must be stored in pans or trays made of a chemically-compatible material to minimize accidental spills. Containers should be of sufficient capacity to contain the material should the primary container accidentally break. All containers, equipment, and materials potentially contaminated with these hazardous chemicals must be appropriately identified with warning labels (e.g. SUSPECT CANCER AGENT, REPRODUCTIVE HAZARD, and HIGHLY TOXIC SUBSTANCE). Labels are available free of charge from RMS (621-1790). If possible, storage areas for these hazardous chemicals must have limited access and shall be maintained at a negative pressure with respect to surrounding areas (e.g. in a fume hood). If this in not possible, these hazardous chemicals must be stored in appropriate double containers (i.e. one compatible container inside another compatible container).

1.11.3) Additional Disposal Requirements: All hazardous chemical waste and contaminated articles which cannot be easily decontaminated, must be disposed of in accordance with the disposal requirements described in Chemical Management Best Practices – Hazardous Chemical Disposal. In addition to the standard hazardous waste disposal requirements, all waste containers must be appropriately identified with appropriate warning labels (as described in Section to alert those disposing of the waste.

1.11.4) Decontamination: Decontamination procedures must be defined for all designated areas. They shall include the following features: Contaminated apparatus, glassware, clothing, and shoes must be thoroughly decontaminated by an effective means or deposited in appropriate, labeled waste containers before being removed from the designated area. Work surfaces potentially contaminated by these hazardous chemicals must be thoroughly decontaminated by an effective means before normal work is resumed in the location. If the hazardous chemical is a dry powder, a wet mop or a vacuum cleaner equipped with a high efficiency particulate air (HEPA) filter must be used to conduct decontamination. Vacuum pumps potentially exposed to these hazardous chemicals must have their oil replaced. The potentially contaminated oil must be disposed of as hazardous wastes. Hands and forearms, and face and neck if necessary, must be thoroughly washed before leaving the designated area. If using toxicologically significant quantities of such hazardous chemicals on a regular basis (e.g. 3 times a week), consult RMS (621-1790) concerning the desirability of regular medical surveillance. If a highly toxic chemical is being used, there must be two people present in the area at all times. Accurate records of the amount of these hazardous chemicals stored and used, the dates of use, and the names of the users must be kept. Such records may be kept in a laboratory person's research notebook. Contingency plans (i.e., a written plan describing what to do if things go wrong), equipment, and materials to minimize exposures of people and property in case of accident must be available.

1.11.5) Animal Work: For large scale studies, University Animal Care Facilities with restricted access are preferable. Administration of the Chemical: When possible, chemical administration must occur by injection or gavage instead of in the diet. If administration must be in the diet, a caging system under negative pressure or under laminar air flow directed toward high efficiency air (HEPA) filters must be used. Aerosol Suppression: Procedures must be devised which minimize the formation and dispersal of contaminated aerosols, including those from food, urine, and feces (e.g. HEPA filtered vacuum equipment for cleaning, moisten contaminated bedding before removal from the cage, mix diets in closed containers in a hood). Personal Protection: When working in the animal room, plastic or rubber gloves and a fully buttoned laboratory coat or jumpsuit must be worn. If needed because of incomplete suppression of aerosols, other apparel and equipment (shoes and head coverings, respirator, etc.) must be utilized (see Section

1.12) Hazardous Chemical Disposal: Laboratory Supervisors are responsible for ensuring that all used and/or unneeded hazardous chemicals (as described in Chemical Safety Information – Chemical Hazards Overview), or articles irreversibly contaminated with these hazardous chemicals, are disposed of according to requirements described in Chemical Management Best Practices – Hazardous Chemical Disposal (see also, the Chemical Waste Disposal Basics Poster – PDF format). RMS reserves the right to deny acceptance of any hazardous waste which was generated, containerized, labeled, or accumulated in a manner inconsistent with these practices. Generators of hazardous waste which is not acceptable for disposal, are financially responsible for the proper and legal disposal of such materials.

1.13) Hazardous Waste Minimization/Pollution Prevention: The cost of disposing of excess and waste chemicals has become extremely expensive, and frequently exceeds the original cost of purchasing the chemical. Every reasonable effort must be made to reduce the generation of hazardous waste (refer to Chemical Management Best Practices – Hazardous Waste Minimization/Pollution Prevention).

1.14) Close-Out Procedure for Departing Personnel: Administrators for each department and supervisors of each lab must initiate a close-out procedure for the permanent departure of any laboratory personnel to ensure all hazardous materials have been either donated to another responsible party or properly disposed of.

1.14.1) This procedure must take place prior to the individual leaving the University or a laboratory and before the lab space is reassigned (see Laboratory Close-Out Checklist and Procedure –PDF format, for guidance).

Go to General Laboratory Chemical Safety Practices Section Two