Chemical Hoods Research Articles

Exposure and Management of the Health Risk for the Use of Formaldehyde and Xylene in a Large Pathology Laboratory

Formaldehyde and xylene are two hazardous chemicals widely used in pathology laboratories all over the world. The aim of this work was to survey a large volume pathology lab, measuring exposure of workers and residents to formaldehyde and xylene, and verify the efficacy of the undertaken preventive actions and the accomplishment with occupational limit values. Environmental, personal, and biological monitoring of exposure to formaldehyde and xylene in different lab rooms and in 29 lab attendants was repeated yearly from 2017 to 2020. Continuous monitoring of airborne formaldehyde was performed to evaluate the pattern of airborne concentrations while specific tasks were performed. Several risk management and mitigation measures, including setting a new grossing room, reducing the number of samples to be soaked in formaldehyde, and improving the lab practices and equipment, such as the use of chemical hoods, were undertaken after each monitoring campaign, based on the results obtained from the exposure monitoring. Significant exposures to formaldehyde in pathologists and residents, especially during the grossing of samples, were observed in the first 2 years, with exposure exceeding the occupational exposure limit value; the following surveys showed that the risk management and mitigation measures were effective in reducing airborne concentrations and personal exposure. Xylene, assessed with both environmental and biological monitoring, was always well below the occupational exposure limit value and biological limit values, respectively. Critical exposure to air formaldehyde in attendants of a pathology laboratory could be reduced with the re-organization of lab spaces, new and improved work procedures, and awareness and training initiatives.

Qualitative Evaluation of Chemical hoods Performance of Laboratories of the University of Medical Sciences

Qualitative Evaluation of Chemical hoods Performance of Laboratories of the University of Medical Sciences

Open source laboratory sample rotator mixer and shaker

An open-source 3-D printable laboratory sample rotator mixer is developed here in two variants that allow users to opt for the level of functionality, cost saving and associated complexity needed in their laboratories. First, a laboratory sample rotator is designed and demonstrated that can be used for tumbling as well as gentle mixing of samples in a variety of tube sizes by mixing them horizontally, vertically, or any position in between. Changing the mixing angle is fast and convenient and requires no tools. This device is battery powered and can be easily transported to operate in various locations in a lab including desktops, benches, clean hoods, chemical hoods, cold rooms, glove boxes, incubators or biological hoods. Second, an on-board Arduino-based microcontroller is incorporated that adds the functionality of a laboratory sample shaker. These devices can be customized both mechanically and functionally as the user can simply select the operation mode on the switch or alter the code to perform custom experiments. The open source laboratory sample rotator mixer can be built by non-specialists for under US$30 and adding shaking functionality can be done for under $20 more. Thus, these open source devices are technically superior to the proprietary commercial equipment available on the market while saving over 90% of the costs.

A new quantitative method for testing performance of in-use laboratory chemical fume hoods

The American Society of Heating and Air-Conditioning Engineers (ASHRAE) 110-1995 tracer gas test method is a well-established measure of laboratory chemical hood performance, but it requires expens...

Laboratory safety for chemistry students

Preface to the Students. To the Instructor. Acknowledgments. Acronyms. Chapter 1 Principles, Ethics, and Practices. 1.1.1 The Four Principles of Safety. 1.1.2 What is Green Chemistry? 1.2.1 Rethinking Safety: Learning from Laboratory Incidents. 1.2.2 Green Chemistry in Organic Chemistry. 1.3.1 Fostering a Safety Culture. 1.3.2 Employers' Expectations of Safety Skills for New Chemists. 1.3.3 Laws and Regulations Pertaining to Safety. 1.3.4 Green Chemistry - The Big Picture. Chapter 2 Emergency Response. 2.1.1 Responding to Laboratory Emergencies. 2.1.2 Fire Emergencies in Introductory Courses. 2.1.3 Chemical Spills: On You and in the Lab oratory. 2.1.4 First Aid in Chemistry Laboratories. 2.2.1 Fire Emergencies in Organic and Advanced Courses. 2.2.2 Chemical Spills: Containment and Clean-up. Chapter 3 Understanding and Communicating about Laboratory Hazards. 3.1.1 Routes of Exposure to Hazards. 3.1.2 Learning the Language of Safety: Signs, Symbols, and Labels. 3.1.3 Finding Hazard Information Material Safety Data Sheets (MSDS). 3.2.1 The Globally Harmonized System of Classification and Labeling of Chemicals (GHS). 3.2.2 Information Resources About Laboratory Hazards and Safety. 3.2.3 Interpreting MSDS Information. 3.3.1 Chemical Hygiene Plans. Chapter 4 Recognizing Laboratory Hazards: Toxic Substances and Biological Agents. 4.1.1 Introduction to Toxicology. 4.1.2 Acute Toxicity. 4.2.1 Chronic Toxicity. 4.3.1 Carcinogens. 4.3.2 Biotransformation, Bioaccumulation, and Elimination of Toxicants. 4.3.3 Biological Hazards and Biosafety. Chapter 5 Recognizing Laboratory Hazards: Physical Hazards. 5.1.1 Corrosive Hazards in Introductory Chemistry Laboratories. 5.1.2 Flammables - Chemicals with Burning Passions. 5.2.1 Corrosives in Advanced Laboratories. 5.2.2 The Chemistry of Fire and Explosions. 5.2.3 Incompatibles A Clash of Violent Proportions. 5.3.1 Gas Cylinders and Cryogenic Liquid Tanks. 5.3.2 Peroxides Potentially Explosive Hazards. 5.3.3 Reactive and Unstable Laboratory Chemicals. 5.3.4 Hazards from Low or High Pressure Systems. 5.3.5 Electrical Hazards. 5.3.6 Housekeeping in the Research Laboratory - The Dangers of Messy Labs. 5.3.7 Nonionizing Radiation and Electric and Magnetic Fields. 5.3.8 An Array of Rays Ionizing Radiation Hazards in the Laboratory. 5.3.9 Cryogenic Hazards A Chilling Experience. 5.3.10 Runaway Reactions. 5.3.11 Hazards of Catalysts. Chapter 6 Risk Assessment. 6.1.1 Risk Assessment - Living Safely with Hazards. 6.2.1 Using the GHS to Evaluate Chemical Toxic Hazards. 6.2.2 Understanding Occupational Exposure Limits. 6.3.1 Assessing Chemical Exposure. 6.3.2 Working or Visiting in a New Laboratory. 6.3.3 Safety Planning for New Experiments. Chapter 7 Minimizing, Controlling and Managing Hazards. 7.1.1 Managing Risk Making Decisions about Safety. 7.1.2 Laboratory Eye Protection. 7.1.3 Protecting Your Skin Clothes, Gloves and Tools. 7.1.4 Chemical Hoods in Introductory Laboratories. 7.2.1 More about Eye and Face Protection. 7.2.2 Protecting Your Skin in Advanced Laboratories. 7.2.3 Containment and Ventilation in Advanced Laboratories. 7.3.1 Safety Measures for Common Laboratory Operations. 7.3.2 Radiation Safety. 7.3.3 Laser Safety. 7.3.4 Biological Safety Cabinets. 7.3.5 Protective Clothing and Respirators. 7.3.6 Safety in the Research Laboratory. 7.3.7 Process Safety for Chemical Operations. Chapter 8 Chemical Management: Inspections, Storage, Wastes, and Security. 8.1.1 Introduction to Handling Chemical Wastes. 8.2.1 Storing Flammables and Corrosives. 8.3.1 Doing Your Own Safety Inspection. 8.3.2 Managing Chemicals in Your Laboratory. 8.3.3 Chemical Inventories and Storage. 8.3.4 Handling Hazardous Laboratory Waste. 8.3.5 Chemical Security. Index.

Solvent vapor concentrations following spills in laboratory chemical hoods

Chemical hoods are universally recognized as an important engineering control for protecting laboratory workers from chemical exposures. However, recent discussions have renewed questions about possible fire and explosion hazards following spills of flammable liquids inside hoods, and the subsequent potential impacts on laboratory design. In response to similar concerns about systems planned for our institution, we simulated a series of spills with flammable solvents to evaluate the potential for generating explosive atmospheres in laboratory hoods. As part of these tests, we also evaluated the effect of different face velocities and volumetric flows on evaporation rates and flammable vapor concentrations. We found that under the normal range of laboratory room and hood operating conditions, the principal determinant of chemical concentration in exhaust air is vapor pressure, and that volumetric airflow has a significantly greater impact on peak vapor concentration than hood face velocity. Based upon these tests, laboratory-scale spills of common flammable liquids are unlikely to create explosive atmospheres in chemical hood exhaust systems.

Protecting service and maintenance workers during laboratory chemical hood repairs

Laboratory chemical hoods may be the single most important engineering control for protecting laboratory workers from chemical exposures, but their maintenance and repair can present potential health and safety hazards to facilities staff. We performed a comprehensive survey of chemical hood systems in laboratory intensive buildings here at Yale University, including an assessment of air quality in Chemistry Department mechanical rooms where fan systems must be accessed by service and maintenance staff. Air monitoring in these mechanical rooms showed intermittently measurable concentrations of many laboratory chemicals, but their magnitudes when present were very low, ranging from about 10 to more than 6,000 times below their applicable permissible exposure limits. Despite the perception by many facilities staff that chemical exposures are their greatest hazard, we found that traditional physical safety issues are the most prevalent source of risk to those responsible for laboratory hood maintenance.

Report of the Howard Hughes Medical Instituteʼs Workshop on the Performance of Laboratory Chemical Hoods

Report of the Howard Hughes Medical Instituteʼs Workshop on the Performance of Laboratory Chemical Hoods

Report of the Howard Hughes Medical Institute's workshop on the performance of laboratory chemical hoods.

The Howard Hughes Medical Institute sponsored a workshop on laboratory chemical hoods on June 8, 9, and 10, 1998, that brought together 24 experts in the field of laboratory chemical hoods to critically assess the information known about hood performance. Workshop participants developed 31 consensus statements that reflect their collective views on the body of knowledge or lack thereof, for laboratory chemical hoods. The consensus statements fall into four broad categories: (1) hood selection, use, and operation; (2) hood and laboratory design issues; (3) ventilation system design issues; and (4) hood performance testing. The consensus statements include 26 statements on what is known and unknown about the performance of laboratory chemical hoods, 2 statements of definition, and 3 statements that reflect the participants' agreement not to agree. The brief commentary that follows each consensus statement provides guidance and recommendations.

Exposure assessment of laboratory students.

The Massachusetts Institute of Technology (MIT) has two kinds of laboratories, teaching for undergraduate students and research laboratories for graduate students and research staff. The objective of this study is to determine chemical exposures during teaching and research activities. There are three hypotheses in this study: (1) Exposures in academic laboratories are well below health standards; (2) Students in undergraduate teaching laboratories have less chemical exposure compared to students in graduate research laboratories; and (3) Students in different disciplines are expected to have different exposures. From September 1996 to December 1996, 132 air samples were collected from both teaching and research laboratories in the departments of Material Sciences and Engineering, Chemical Engineering, and Biology. The most frequently sampled chemicals in these three departments were cobalt, styrene, and formaldehyde, respectively. A total of 23 different agents were measured. In this study, the American Conference of Governmental Industrial Hygienists (ACGIH) threshold limit value (TLV)-short-term exposure limit (STEL) is used as the health-effect standard for exposure time less than four hours. The ACGIH TLV-TWA (time-weighted average) is used as the standard for exposure times equal to or greater than four hours. The ratio of measured concentrations to the appropriate ACGIH standard was then calculated. The geometric mean of the ratio for the total samples was 0.34 percent of the standards. There were 70 samples from teaching laboratories (geometric mean = 0.38% of the standards), and 62 samples from research laboratories (geometric mean = 0.08% of the standards). The chemical exposures relative to the standards in teaching laboratories were statistically higher than in research laboratories (p-value < 0.001). Information about personal protective equipment and the use of laboratory chemical hoods was also collected. The differences in use of personal protective equipment (PPE) among these departments was not statistically significant. From the air sampling results, we concluded that (1) Chemical exposures in the academic laboratories in this study were all well below the health standards; (2) Undergraduate students in teaching laboratories had higher chemical exposures than graduate students in research laboratories; (3) Chemical exposures among departments were not significantly different; and (4) Hazard communication, safety training, and laboratory rules enforcement are important for protection and may be the reason that the results from this study indicate that chemical exposures in this academic institution are well below the health standards under normal operations.

Chemical Hood Performance: Standards, Guidelines, and Recommendations

Chemical hoods are important pieces of laboratory equipment and are essential to the supporting ventilation system. Extending consensus for optimizing chemical hood performance would benefit all co...

Development of a Program for Performance Evaluation of University Specialty Local Exhaust Systems for Compliance with the OSHA Laboratory Standard

Abstract Research facilities at the university where this program was developed currently occupy about 3200 laboratories containing 900 chemical laboratory hoods. A program of annual surveys of hood performance has been in place for 30 years. In addition to chemical laboratory hoods, university laboratories also contain more than 1300 specialty local exhaust ventilation (SLEV) systems for laboratory instrumentation, engineering pilot plant operations, semiconductor fabrication clean rooms, and physical plant shops. To comply with the Occupational Safety and Health Administration Laboratory Standard 1910.1450, which requires verification that engineering controls are performing adequately, we developed a program to monitor performance of SLEV systems. Program development included: (1) survey of all laboratory spaces and identification of SLEV systems; (2) classification of systems and uses; (3) evaluation of design criteria by comparison with existing American Conference of Governmental Industrial Hyggenis...

Laboratory hood studies

The objective of this study was to assess and characterize a number of the bench-type chemical laboratory hoods typical of those at the DuPont Company's experimental station to determine the levels of protection provided for personnel working at these hoods.

Perchlorate testing in chemical apparatus and hoods

Perchlorate testing in chemical apparatus and hoods