SCIENCEMADNESS.ORG  - THE AMATEUR EXPERIMENTER’S GUIDE TO LABORATORY SAFETY by Hexavalent

 

A complete and comprehensive safety guide for the practicing amateur chemist, featuring discussions on Personal Protective Equipment (PPE), mechanical safety devices and general lab practices.

                            The techniques used in modern chemistry in all fields of research, from physical to synthetic organic to preparative inorganic, often demand the handling of hazardous chemicals, equipment and other supplies which can cause fatal injury or death if misused. Thus, the necessity of  laboratory safety is highlighted and many an amateur experimenter has been admitted to hospital with serious injuries or have even died due to the careless handling of their chemicals and supplies. In this article, we will discuss the types of safety equipment used in laboratories, their usage, why they are needed, as well as what must be done in the event of an accident and general lab practices that supplement safety and significantly reduce the possibility for the latter to happen.

              The primary aspect of laboratory safety is Personal Protective Equipment, or PPE. There are five main aspects of this section, namely protective eye/facewear, protective gloves, protective clothing, respiratory protection and hearing protection. We shall initially discuss eyewear, perhaps one of the most important aspects, as the eyes are very sensitive to foreign materials and debris. It is here, before and further discussions, it should be noted that contact lenses are usually forbidden in laboratories, as vapours, mists and corrosive liquids can often ‘weld’ them to the surface of the eye, potentially seriously damaging the latter and hindering irrigation if a chemical is splashed into the eyes. Thus, they should be removed before entering work areas and replaced, if absolutely necessary, with prescription spectacles. However, the most most common type of protective eyewear  to protect the eyes in the event of a splash is the popular safety glasses, seen below, and many different models exist—standard versions, those that are designed to fit over prescription spectacles, brand-name glasses and so forth. The lenses are usually made from polycarbonate plastic, due to its high impact resistance, and glasses are often favourited as they are light on the face and thus more pleasurable to wear for extended periods of time. Many modern models are also available, which reduce the ‘bulky’ feeling to an even greater extent. Presciption safety glasses, which essentially combine the adjustments required for the correction of an individual’s vision and a safety device, are also widely available, in addition to simple clip-on shields for normal glasses, but these may be expensive.                         However, safety glasses are often diapproved by many chemists, many of them working in the professional and/or industrial fields, mainly as they do not seal completely to the face, thus potentially exposing the eyes to harmful materials—a fateful accident involving deuterated chloroform that rendered a student partially blind was once observed, when she incorrectly filled  a chromatography setup with the aforementioned solvent, causing pressure to build up, a minor explosion, and the solvent seeping in through the gap where the safety glasses met her forehead. In this situation, safety goggles, which essentially provide a complete seal around the eyes, would have significantly reduced the chances of her being injured. However, even with these special care must still be taken to select the correct type; many goggles sold, for example, in hardware stores contain rows of tiny holes poked in the sides for ventilation (see below) that make them unsuitable for laboratory use. These goggles are designed to protect against impact hazards, such as using a grinder or other power tools, not for resisting against splashed liquids; they can simply run through the holes and into the eye cavity area. Therefore, models featuring ‘cap vents’, as shown in the blue goggles on the left, should be purchased; they still allow for adequate ventilation, to reduce fogging up of the goggles, but due to their design do not allow liquids to pass through. These goggles are sometimes carried locally, but often enough the best location for purchasement is on the internet, notably from websites such as www.eBay.com where they are available inexpensively, often in packs of two which is convenient as a spare or for lab assistants, and in multitudes of colours for personal preference.