Laboratory work safety

The preparation of the sample to be investigated must, of course, meet the usual requirements of laboratory work safety and security demands have to be followed any risk must be avoided. This is especially important in case of materials with unknown properties. 

SAFETY PRECAUTIONS to be observed during Laboratory Work. 

Laboratory work with hydrogen cyanide should be carried out only in a well-ventilated fume hood. Special safety equipment such as air masks, face masks, plastic aprons, and mbber gloves should be used. A chemical proof suit should be available for emergency. Where hydrogen cyanide is handled inside a building, suitable ventilation must be provided. The people involved should be thoroughly trained in first aid. 

Lawrence Livermore National Laboratory. Work enclosures for toxic and radioactive materials. In Environmental Safety and Health Manual. September 1995. 

Laboratories working frequently with flammables, such as in extraction processes, may set aside a separate room for such work for maximum safety. Ideally, this room should have explosion-proof electrical equipment and special ventilation. Rigid work rules should be enforced, such as requiring workers to leave matches and lighters on a shelf outside before entering. Installation of conductive flooring should be considered, and steel tools should be prohibited at times when work is in progress. 

Eye protection is mandatory for almost all types of laboratory work. A wide selection of safety glasses and goggles is available from suppliers of safety equipment, many especially designed for specific purposes. There are official specifications for such glasses, and it is unwise to buy any w hich are claimed to be as good as the ones guaranteed to meet those specifications. 

Facilities and procedures necessary to encourage safety in laboratory work... 

It should be obvious from a scientific standpoint that the question of microwave effects needs to be addressed in a serious manner, given the rapid increase in the use of microwave technology in chemical sciences, in particular organic synthesis. There is an urgent need to remove the black box stigma of microwave chemistry and to provide a scientific rationalization for the observed effects. This is even more important if one considers safety aspects once this technology moves from small-scale laboratory work to pilot- or production-scale instrumentation. 

It is often necessary to carry out some reagent preparation. This may seem a trivial aspect of laboratory work, but its importance is often underestimated. It is a common source of error and it is worth taking a little bit of time to ensure reagents and, in particular, standards are correctly made-up. Very simple principles are involved. Follow any instructions available, implement safety instructions, use equipment properly and check that you know what you are doing before you start. 

Note The review of laboratory experiments in this book are not meant to replace detailed laboratory procedures, disposal and safety concerns. Under NO circumstances are the scenarios for the labs to be used as directions for actually performing the laboratory work. See the bibliography at the end of this book for a list of resources that provide detailed directions. 

SACHEM Inc., located in Cleburne, Texas, is a producer of high-purity bulk chemicals for companies that have high-purity requirements in their chemical processing. Because the products are of high purity, laboratory operations to assure the quality of the products (quality assurance operations) involve the determination of trace levels of contaminants. Contamination of laboratory samples and materials is of special concern in cases like this because an uncommonly small amount of contaminant can adversely affect the results. The laboratory work therefore takes place in a special environment called a clean room. A clean room is a space in which extraordinary precautions are taken to avoid the slightest contamination. Laboratory personnel wear special clean room suits, nets to cover hair, mustaches, and beards, and special shoes, gloves, and safety glasses to minimize possible contamination. 

Many of the chemicals and much of the equipment used in laboratories are potentially hazardous. It is essential that these hazards are clearly identified and appropriate working procedures defined together with adequate training of staff and readily available facilities to deal with the effects of any possible accident. These aspects of laboratory work are covered in the UK by COSHH (Control of Substances Hazardous to Health) Regulations and by OSHA (Occupational Safety and Health Administration) in the USA. 

There are a number of critical elements in an efficient university clinical pharmacology department. They include teaching, analytical and experimental laboratory work, clinical service, drug information and critical appraisal, advisory support for the professions, drug safety research and evaluation, and pharmacovigilance. 

Normal safety precautions for laboratory work and for the use of electrical equipment, especially variable temperature accessories, must be observed. The thermal analysis experiment involves high temperatures and there is a danger of being burned. Consult instrument operating manual for specific cautions regarding operation. 

When performing laboratory work in inorganic synthesis, one has to assemble the required apparatus or setup from individual components, generally made of glass. The success of an experiment and also its safety often depend on the quality of apparatus assembly. This is especially important in the synthesis of readily hydrolyzing substances, and also in work performed in an atmosphere of hydrogen, carbon monoxide, or chlorine. 

CISHC Chem. Safety Summ., 1977, 48, 25 Shaw, A. W., private comm., 1978 During the vacuum fractional distillation of bulked residues (7.2 t containing 30— 40% of the bis(hydroxyethyl) derivative, and up to 900 ppm of iron) at 210—225°C/ 445—55 mbar in a mild steel still, a runaway decomposition set in and accelerated to explosion. Laboratory work on the material charged showed that exothermic decomposition on the large scale would be expected to set in around 210—230°C, and that the induction time at 215°C of 12—19 h fell to 6—9 h in presence of mild steel. Quantitative work in sealed tubes showed a maximum rate of pressure rise of 45 bar/s, to a maximum developed pressure of 200 bar. The thermally induced decomposition produced primary amine, hydrogen chloride, ethylene, methane, carbon monoxide and carbon dioxide. 

A detailed analysis of all types of laboratory hazards and the procedures for dealing with them is beyond the scope of this book. Specific hazards are pointed out in coimec-tion with individual experiments. It is also assumed that the instructing staff will provide specific warnings and reminders where needed. Some general remarks on the kinds of safety hazards that should be kept in mind are given in Appendix C, and very complete treatments can be found elsewhere. At this point, we wish to stress a few basic principles that apply to all laboratory work. 

The ballast bulb must be taped to prevent flying glass fragments in the unlikely event of breakage. Safety glasses should be worn for all laboratory work. Gas cylinders must be chained securely to the wall or laboratory bench (see pp. 644-646 and Appendix C). Liquid nitrogen must be handled properly (see Appendix C). 

Precaution Do not raise the temperatnre of the thermostat bath appreciably above the critical temperature, as the pressure increase in the capillaries conld possibly canse them to explode (the critical pressnre of CO2 is 73.8 bar = 72.9 atm). Althongh the possibility of explosion is remote, the wearing of safety glasses, which shonld be mandatory practice in all laboratory work, shonld be particnlarly emphasized in this experiment. 

The prospect that a sealed capillary tube will explode due to excessively high internal pressure is quite remote, but it is prudent not to heat the capillaries above 32°C. Even if one of the tubes were to explode, no damage is likely since they are immersed in a thermostat water bath. Nevertheless, the importance of wearing safety glasses for all laboratory work should be stressed. 

Review experimental procedures and identify possible safety hazards before beginning laboratory work. 

An introduction to the current techniques and methods of analytical and preparative biochemistry. In addition to the core methodologies of sample preparation, separation and analysis, the authors discuss the application of immunological and biophysical approaches to the study of biochemical systems, as well as advising on biochemical literature, equipment and safety aspects of laboratory work. 

It has been emphasized already that you should be familiar with the regulations and codes of practice pertaining in your laboratory. We will not discuss safety legislation here but some fundamental rules should be stressed. Never work alone in a laboratory. Always wear suitable safety spectacles and a cotton lab coat, and use other protection such as gloves, face masks, or safety shields if there is a particular hazard. Never eat, drink or smoke in a laboratory. Work at a safe, steady pace, and keep your bench and your lab clean and tidy. Familiarity breeds contempt do not allow yourself to get careless with everyday dangers such as solvent flammability. Familiarize yourself with the location and operation of the safety equipment in your laboratory. 

The outcome of the risk assessment process must be recorded and appropriate safety information must be passed on to those at risk. For most practical classes, risk assessments will have been carried out in advance by the person in charge and the information necessary to minimize the risks to students may be given in the practical schedule. You will be asked to carry out risk assessments to familiarize yourself with the process and sources of information. Make sure you know how your department provides such information and that you have read the appropriate material before you begin your practical work. You should also pay close attention to the person in charge at the beginning of the practical session, as they may emphasize the major hazards and risks. In project work, you will need to be involved in the risk assessment process along with your supervisor, before you carry out any laboratory work. Any new materials synthesized during the project should be treated with the utmost respect. An example of a risk assessment is shown in Fig. 2.2. 

Always clear up at the end of each session. This is an important aspect of safety, encouraging a responsible attitude towards laboratory work. 

You are most likely to encounter paraffin oil baths during your laboratory work and the following safety points should be considered ... 

First, regarding safety, the I.O.N.S. safety manual is included herein. We are very proud of the fact that only minor safety violations have occurred since our company was founded in 1978. We expect that all safety policies and procedures outlined in the manual will be in effect at all times. For this reason, it is imperative that you diligently study and familiarize yourself with the material contained in this manual. Before you are permitted to do any laboratory work, you must satisfactorily demonstrate your knowledge of safety to your supervisor. He or she will go over the safety manual with you and point out important aspects of your specific workspace. In addition, Ben Whell, the I.O.N.S. Safety Coordinator, provides a safety report for all projects that require special attention with respect to safety. 

No laboratory work should be carried out without due regard to safety, both for yourself and for the people around you. While the Health and Safety at Work... 

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