Experimental safety

If the DTA or DSC are used as true screening tools in experimental safety testing, which in other words, means that there is not much more information available on the substance to be tested than the explosibility assessment according to the oxygen balance calculation, it may generally be recommended to use stainless-steel sample containers, which can withstand pressure up to 200 bar for the first tests. 

Rompe, K., Schindler, A., and WaUrich, M. 1987. Advantages of an anti wheel lock system (ABS) for the average driver in difficult driving situations. In Proceedings of the 11th International Technical Conference on Experimental Safety Vehicles, Washington, DC, 442-448. 

Performance in the New Car Assessment Program with Fatality Risk in Actual Head on Collisions. Proceedings of the Experimental Safety Vehicle (ESV) Conference. Paper no. 94-S8-0-11, Vol. 2, pp. 1388-1404. Munich. 

Neale, V. L., T. A. Dingus, S. G. Klauer, J. Sudweeks and M. Goodman (2005). An overview of the 100-car naturalistic study and findings. Experimental Safety Vehicles (ESV) conference Paper Number 05-0400. Washington, DC. 

Brooks, A. M., D. P. Chiang, T. A. Smith, J. W. Zellner, J. P. Peters and J. Compagne (2005). A driving simulator methodology for evaluating enhanced motorcycle conspicuity. 19 Annual Conference of Experimental Safety Vehicles. Paper 05-0259, U.S. Department of Transportation, Washington DC,... 

Pedder, J. B., J. R. Hurt and D. Otte (1979). Motorcycle accident impact conditions as a basis for motorcycle crash tests. In Proceedings of the 12th NATO conference on Experimental Safety Vehicles. 

A great deal of experimental work has also been done to identify and quantify the ha2ards of explosive operations (30—40). The vulnerabiUty of stmctures and people to shock waves and fragment impact has been well estabUshed. This effort has also led to the design of protective stmctures superior to the conventional barricades which permit considerable reduction ia allowable safety distances. In addition, a variety of techniques have been developed to mitigate catastrophic detonations of explosives exposed to fire. 

It is good practice to keep concentrations of airborne nickel in any chemical form as low as possible and certainly below the relevant standard. Local exhaust ventilation is the preferred method, particularly for powders, but personal respirator protection may be employed where necessary. In the United States, the Occupational Safety and Health Administration (OSHA) personal exposure limit (PEL) for all forms of nickel except nickel carbonyl is 1 mg/m. The ACGIH TLVs are respectively 1 mg/m for Ni metal, insoluble compounds, and fume and dust from nickel sulfide roasting, and 0.1 mg/m for soluble nickel compounds. The ACGIH is considering whether to lower the TLVs for all forms of nickel to 0.05 mg/m, based on nonmalignant respiratory effects in experimental animals. 

Pilot plants are often more hazardous than process plants, even though they are smaller ia size, for many reasons. These iaclude a tendency to relax standard safety review procedures based on the small scale, exceptionally qualified personnel iavolved, and the experimental nature of the research operations the lack of estabhshed operational practice and experience lack of information regarding new materials or processes and lack of effective automatic iatedocks due to the frequendy changing nature of pilot-plant operations, the desire for wide latitude in operating conditions, and the lack of hill-time maintenance personnel. 

Appendix 6 contains requirements of experimental stress analysis. Appendix 8 has acceptance standards for radiographic examination. Appendix 9 covers nondestructive examination. Appendix 10 gives rules for capacity conversions for safety valves, and Appendix 18 details quahty-control-system requirements. 

Table A.4, taken from the CCPS Guidelines for Chemical Reactivity Evaluation and Application to Process Design, shows the questions which need to be asked regarding the safety of the proposed reaction, the data required to answer those questions and some selected methods of investigation. The experimental analysis is extremely specialized, and companies should consider outsourcing the tests if they do not have specialists in this area.

Experimental chemistry is a very dangerous occupation and extreme care and adequate safety precautions should be taken at all times. Although we have stated the safety measures that have to be taken under specific entries these are by no means exhaustive and some may have been unknowingly or accidentally omitted. The experimenter without prior knowledge or experience must seek further safety advice on reagents and procedures from experts in the field before undertaking the purification of any material. We take no responsibility whatsoever if any mishaps occur when using any of the procedures described in this book. 

The hazards and safety preeautions for seleeted eommon eompressed gases are diseussed below to illustrate the general approaeh. More details should be sought from suppliers. Some methods for their preparation in situ are noted full experimental details must be obtained from the literature. 

Safety requires that only the most reliable experimentally determined flammable limit data be considered in purging calculations. This is included in Table 3. 

Colenbrander, G. W. and J. S. Puttock, 1983, Dense Gas Dispersion Behavior Experimental Observations and Model Developments, International Symposium on Loss Prevention and Safety Promotion in the Process Industries, Harrogate, England, September. 

Hazard identification, step one, means identification of new chemicals or other factors that may cause harmful health effects. Previously, novel hazards were usually observed in case studies or after accidents or other excessive exposures, usually in occupational environments. Today, thorough toxicity studies are required on all pesticides, food additives, and drugs. New chemicals also have to be studied for their potential toxic effects. Thus, earlier hazards were in most cases identified after they had caused harmful effects in humans. Today, most chemical products have been evaluated for their toxicity with experimental animals. Therefore, hazard identification has become a preventive procedure based on safety studies conducted before a chemical compound or product reaches the market, and before individuals are exposed to it. ... 

TABLE 5.24 Toxicity Studies for Safety Evaluation of Drugs, Pesticides, Food Additives, and Other Chemicais Utilizing Experimental Animals and Other Systems Required by Health Authorities... 

In risk characterization, step four, the human exposure situation is compared to the toxicity data from animal studies, and often a safety -margin approach is utilized. The safety margin is based on a knowledge of uncertainties and individual variation in sensitivity of animals and humans to the effects of chemical compounds. Usually one assumes that humans are more sensitive than experimental animals to the effects of chemicals. For this reason, a safety margin is often used. This margin contains two factors, differences in biotransformation within a species (human), usually 10, and differences in the sensitivity between species (e.g., rat vs. human), usually also 10. The safety factor which takes into consideration interindividual differences within the human population predominately indicates differences in biotransformation, but sensitivity to effects of chemicals is also taken into consideration (e.g., safety faaor of 4 for biotransformation and 2.5 for sensitivity 4 x 2.5 = 10). For example, if the lowest dose that does not cause any toxicity to rodents, rats, or mice, i.e., the no-ob-servable-adverse-effect level (NOAEL) is 100 mg/kg, this dose is divided by the safety factor of 100. The safe dose level for humans would be then 1 mg/kg. Occasionally, a NOAEL is not found, and one has to use the lowest-observable-adverse-effect level (LOAEL) in safety assessment. In this situation, often an additional un-... 

Experimental variance Permission granted by OSHA for the use of an alternative method of worker protection during an approved experiment to demonstrate or validate new safety and health techniques. The variance terminates upon study com pletion unless another type of variance is issued by OSHA. 

Britton, L. G. 2000a. Using Maximum Experimental Safe Gap to Select Flame Arresters. Process Safety Progress, 19(3), 140-145. 

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