Prudent Practices in the Laboratory: Handling and Management of Chemical Hazards, Updated Version

Citation

National Research Council. (2011). Prudent Practices in the Laboratory: Handling and Management of Chemical Hazards (Updated version). The National Academies Press. https://doi.org/10.17226/12654. Free official edition: https://nap.nationalacademies.org/catalog/12654/prudent-practices-in-the-laboratory-handling-and-management-of-chemical-hazards

Chapter Summary

Chapter 1: The Culture of Laboratory Safety

The opening chapter recalls the "heroic age" of chemistry, when Kekulé repeated Liebig's advice that anyone who wanted to become a chemist had to ruin their health, and contrasts it with today's expectation of a culture of safety built on accountability, teamwork and personal responsibility. It assigns responsibility to laboratory personnel, environmental health and safety (EHS) staff and the head of the organization, and discusses the different needs of high school teaching labs, undergraduate teaching labs and academic research labs, as well as industrial and government labs. It notes influences such as new technology, environmental impact, regulation and accessibility for scientists with disabilities, and explains the book's structure: Chapters 2, 3 and 10 on organization, 4–8 on practice, 9 on facilities and 11 on regulation.

Chapter 2: Environmental Health and Safety Management System

This chapter treats laboratory safety as a management system, with policy, management commitment, planning, implementation, performance measurement and management review, illustrated by the US Department of Energy's Integrated Safety Management System. It describes the Chemical Hygiene Plan, general safety rules (including working alone and avoiding routine exposure), a chemical management program from procurement to waste, a laboratory inspection program (routine inspections, self-audits, peer and external inspections, checklists and corrective actions), emergency procedures and employee training.

Chapter 3: Emergency Planning

New in this edition, the chapter frames emergency management in four phases (mitigation, preparedness, response, recovery). It works through a vulnerability assessment covering fire, flood, severe weather, earthquakes, illness-related absences, spills, violence and theft, and loss of data or critical equipment. It then covers leadership and succession, essential personnel, communication plans and assembly points, evacuation and shutdown of unattended experiments, sheltering in place, short- and long-term power loss, building closure, community emergencies, drills and coordination with outside responders.

Chapter 4: Evaluating Hazards and Assessing Risks in the Laboratory

The longest technical chapter teaches risk assessment before an experiment, which the book makes the primary responsibility of the person doing the work, checked by the supervisor. It reviews information sources: the Chemical Hygiene Plan, material safety data sheets, the Globally Harmonized System, the committee's Laboratory Chemical Safety Summaries, labels and databases. It explains toxicology (dose–response, duration and route of exposure, acute toxicity, irritants and sensitizers, asphyxiants, neurotoxins, reproductive toxins, carcinogens, control banding), then flammable, reactive and explosive hazards (flash points, pyrophorics, incompatibles, peroxide formers, dusts), physical hazards (compressed gases, cryogens, pressure and vacuum, radiation, electricity, magnetic fields, ergonomics), and briefly nanomaterials, biohazards and radioactivity.

Chapter 5: Management of Chemicals

The chemical life cycle is followed from purchase to shipment. The chapter opens with green chemistry applied to every laboratory (preventing waste, microscale work, safer solvents, replacing mercury thermometers), then covers ordering and receiving, inventory and tracking systems, exchange and recycling of chemicals, labelling of commercial, secondary and experimental containers, storage by compatibility (including cold storage, flammables, gas cylinders, highly reactive and highly toxic substances), and the rules for transferring, transporting and shipping chemicals, including nanomaterials.

Chapter 6: Working with Chemicals

This chapter sets out general standard procedures for any work with hazardous chemicals, on the principle that the toxicity of most research chemicals is unknown and exposure should therefore be minimized. It covers prudent planning, personal behaviour, engineering controls and avoiding each route of exposure, housekeeping, scaling up reactions, unattended experiments and working alone, chemistry demonstrations, and responding to spills, injuries and fires. Additional procedures follow for highly toxic substances (designated areas, access control), biohazardous and radioactive materials, flammable substances, reactive and explosive compounds (including peroxide detection and hydrogenation), compressed gases, microwave ovens and nanoparticles.

Chapter 7: Working with Laboratory Equipment

Equipment is a frequent cause of laboratory accidents, and the chapter notes that ordinary hazards such as floods, slips and poor ergonomics account for many injuries. It covers water-cooled equipment, electrical safety, vacuum pumps, refrigerators, stirrers and heating devices (ovens, hot plates, mantles, baths, heat guns, microwaves), distillation and solvent purification systems, centrifuges and ultrasonicators, lasers and other radiation sources, compressed gas cylinders and regulators, pressure vessels, cryogenic liquids, cold traps, vacuum apparatus and rotary evaporators. It ends with personal protective equipment (clothing, eye, face and hand protection) and safety equipment such as spill kits, shields, fire extinguishers, respirators, safety showers and eyewash units.

Chapter 8: Management of Waste

Starting from the principle that no activity should begin until a plan for disposing of its waste exists, the chapter presents a four-tier hierarchy: prevention and source reduction, reuse, treatment and recycling, and disposal. It explains how to characterize waste (including unknowns), the US definitions of characteristic and listed hazardous waste, accumulation and storage rules (with special provisions for academic laboratories), sewer disposal, incineration, transport, manifests and record keeping. Multihazardous wastes (chemical–radioactive, chemical–biological, radioactive–biological) receive separate treatment, and the chapter ends with laboratory-scale procedures for treating acids, bases and other surplus chemicals.

Chapter 9: Laboratory Facilities

Aimed at helping laboratory staff understand and contribute to facility design, this chapter covers layout (separating wet labs from offices, open versus closed labs, furnishings, accessibility under the Americans with Disabilities Act, older buildings) and, at length, ventilation: laboratory chemical hoods (face velocity, factors affecting performance, sash use, testing and design), other local exhaust devices, constant and variable air volume systems, supply and exhaust systems and room pressure control. Special systems include gloveboxes, clean rooms, environmental rooms, biosafety cabinets and enclosures for nanomaterials. Further sections address ventilation management, energy-saving measures for sustainability and decommissioning a laboratory.

Chapter 10: Laboratory Security

The second new chapter distinguishes safety (keeping people safe from chemicals) from security (keeping chemicals safe from people). It lists risks such as theft or diversion of materials, threats from activists, sabotage, loss of sensitive information and unauthorized experimentation, and covers physical, operational and information security, the dual-use potential of laboratory materials, specific requirements for biological agents, animals, radioactive materials, controlled drugs and Department of Homeland Security chemicals of interest, vulnerability assessment, three security levels and training.

Chapter 11: Safety Laws and Standards Pertinent to Laboratories

The final chapter gives an overview, explicitly not a compliance guide, of mainly federal US requirements: OSHA enforcement and the General Duty Clause, the Laboratory Standard compared with the Hazard Communication Standard, exposure limits (PELs, TLVs, RELs), regulations on design and construction, chemical-specific standards, the Chemical Hygiene Plan and particularly hazardous substances, anti-terrorism standards, biohazard and radioactive material rules, environmental regulation of hazardous waste, sewer discharges and air emissions, shipping and export or import (including the TSCA research exemption) and reporting of accidents and releases. Appendix A reprints the OSHA Laboratory Standard.

Key Concepts

Chapters 1–2: The Culture of Laboratory Safety; Environmental Health and Safety Management System

• Culture of safety: an organizational climate in which everyone, from leadership to students, treats safety as part of good science and acts on near misses.
• Hazard versus risk: a hazard is the inherent danger of a material or system; risk depends on how it is used and the exposure that results.
• Chemical Hygiene Plan: the written program required by the OSHA Laboratory Standard that sets out procedures, equipment and training to protect laboratory workers.

Chapter 3: Emergency Planning

• Four phases of emergency management: mitigation, preparedness, response and recovery, each feeding into the others.
• Vulnerability assessment: a structured review of the events most likely to disrupt a laboratory and their consequences.

Chapter 4: Evaluating Hazards and Assessing Risks in the Laboratory

• Dose–response relationship: the toxic effect of a chemical depends on the dose, duration and route of exposure.
• Laboratory Chemical Safety Summary (LCSS): committee-written summaries of physical, toxicological and handling information for laboratory use of selected chemicals.
• Control banding: assigning control measures according to broad bands of hazard when full toxicity data are lacking.
• Peroxide-forming chemicals: compounds that accumulate explosive peroxides during storage and need dating and testing.

Chapter 5: Management of Chemicals

• Green chemistry in the laboratory: designing experiments to prevent waste and use less hazardous substances.
• Storage by compatibility: separating chemicals that could react dangerously, rather than storing them alphabetically.

Chapter 6: Working with Chemicals

• Minimizing exposure to unknowns: treating new or poorly studied substances as potentially hazardous and controlling every route of exposure.
• Designated area: a marked, access-controlled area for work with highly toxic substances.
• Engineering controls before PPE: relying first on hoods and enclosures, with personal protective equipment as an additional layer.

Chapter 7: Working with Laboratory Equipment

• Equipment-related hazards: electrical, pressure, vacuum, temperature and radiation hazards arising from common laboratory apparatus.
• Personal protective equipment: clothing, eye, face and hand protection chosen for the specific hazard.

Chapter 8: Management of Waste

• Waste management hierarchy: prevention and source reduction, reuse, treatment and recycling, then disposal.
• Characteristic and listed waste: the two US regulatory routes by which a waste is classed as hazardous.
• Multihazardous waste: waste combining chemical, radioactive and/or biological hazards, which needs coordinated handling.

Chapter 9: Laboratory Facilities

• Laboratory chemical hood: the primary ventilated enclosure for controlling airborne contaminants, whose performance depends on face velocity, sash position and use.
• Constant versus variable air volume: ventilation designs that either keep airflow fixed or adjust it to demand, with energy implications.

Chapters 10–11: Laboratory Security; Safety Laws and Standards Pertinent to Laboratories

• Dual use: the potential for laboratory materials and knowledge to be misused for harm.
• OSHA Laboratory Standard: the US regulation (29 CFR 1910.1450) governing occupational exposure to hazardous chemicals in laboratories.
• Exposure limits: PELs, TLVs and RELs, the regulatory and advisory airborne concentration limits used in risk assessment.

Critical Analysis

Strengths

• Authoritative and comprehensive. Written by a National Research Council committee and reviewed by many experts, the book covers the whole life of laboratory chemicals, from ordering to disposal, together with equipment, facilities, emergencies, security and regulation. Its numbered, hierarchical sections make it easy to consult as a reference.
• Risk assessment at its centre. Chapter 4 teaches the reasoning behind safety rules (dose–response, exposure routes, flammability classes, reactivity) rather than only listing prohibitions, and Chapter 6 then turns that reasoning into procedures, including the principle of minimizing exposure to substances whose hazards are unknown.
• Practical and specific. Much of the advice is concrete: how to detect peroxides, handle leaking cylinders or mercury spills, set up vacuum apparatus, use a hood sash, store gas cylinders, or neutralize acids and bases at laboratory scale.
• Addresses culture and newer topics. The emphasis on culture, the inclusion of academic and teaching laboratories, and the chapters on emergency planning and security, together with sections on nanomaterials and green chemistry, broaden the subject beyond technical rules.

Limitations

• Dated in places. The book itself notes that, when it was written, US agencies had not yet issued final guidance on the Globally Harmonized System, so it relies mainly on material safety data sheets (MSDSs); hazard-communication formats, regulatory details, exposure limits and nanomaterial guidance should be checked against current sources.
• Strongly US-oriented. Chapters 8 and 11 and many references describe US federal law (OSHA, EPA, TSCA, DOT, DHS). Readers elsewhere must substitute their own regulations, though the risk-assessment principles carry over.
• A reference, not a course text. There are no learning objectives, worked examples or exercises, and the density of the material can overwhelm beginners. The Laboratory Chemical Safety Summaries for 91 substances were supplied on a CD with the print book and are not part of the online chapters.
• Brief on non-chemical hazards. Biohazards and radioactivity are discussed only briefly and readers are referred to specialist sources.

Where It Fits in the Course

In a course on laboratory practice and safety, Prudent Practices is the reference work that the other books build on or apply. Hill and Finster's Laboratory Safety for Chemistry Students is described as a student-oriented safety text, and is the better first read for undergraduates; Prudent Practices then supplies the fuller technical and organizational background for risk assessment, storage, waste and facilities. Practical Skills in Chemistry by Dean and colleagues concentrates on laboratory techniques and skills, and can be paired with Chapters 6 and 7 here, which explain the safety side of the same operations.

For advanced students, Shriver and Drezdzon's The Manipulation of Air-Sensitive Compounds and Leonard, Lygo and Procter's Advanced Practical Organic Chemistry treat specialized synthetic techniques. Reading the relevant parts of Prudent Practices first (reactive and pyrophoric hazards, peroxides, compressed gases, vacuum and cryogenic work, gloveboxes) gives the risk-assessment framework within which those techniques should be carried out.

How to Use This Book

The book addresses everyone who works with or manages chemicals: students, laboratory staff, supervisors, EHS personnel and administrators. First-year general chemistry is enough background for most of it; Chapter 4's toxicology and Chapter 9's ventilation material are accessible without specialist training.

Students should read Chapter 1 and then Chapters 4 and 6 closely, since they contain the core of hazard evaluation and safe practice, followed by the parts of Chapters 5, 7 and 8 that match their laboratory work (storage and labelling, equipment and PPE, waste). Before a new experiment, use Chapter 4 as a checklist for the chemicals and operations involved and Chapter 6 for the procedures that follow. Chapters 2, 3, 9, 10 and 11 are most useful to research group leaders, safety officers and anyone writing a Chemical Hygiene Plan or emergency plan. The book is best combined with current safety data sheets and local regulations, and with the OSHA standard reprinted in Appendix A.

Edition and Sources

This guide is based on the updated version of Prudent Practices in the Laboratory: Handling and Management of Chemical Hazards (National Research Council, The National Academies Press, 2011), read in the free full text available online at the National Academies Press (nationalacademies.org/read/12654, linked from the official catalog page); the PDF download requires a free account, so the online reading edition was used. It draws on the front matter and preface, the full table of contents, all 11 chapters (every section and subsection heading, each chapter's introduction, and Chapter 1 in full), the section on Laboratory Chemical Safety Summaries, Appendix B (statement of task) and the opening of Appendix A.