Drawing, chemical hazards with

It is worthwhile drawing attention to health hazards associated with film infected water systems which also cause corrosion. Two of the most common are Legionnaires disease and so called humidifier fever . Because of strong adhesion of biofilms and diffusion rates through the film treatment based on cleaners and chemical sterilisers such as chlorine often fail similar considerations apply to other systems in industry, e.g. food, paint, oil and gas are examples where biofilm activities have given massive problems. 

The proposed systems framework for EU decision-making under REACH seeks to counterbalance the weaknesses and to draw on the strengths of the national approaches while addressing the points shown in Table 7.1. Specifically, the framework would fuse hazard, technical and risk-benefit approaches to risk management (Table 7.2). Compared with the current process of chemical legislation and the recent REACH proposal, the systems framework would avoid a linear substance-by-substance approach by applying a set of decision-making rules based on hazard and use to all chemicals (Section 5.3.1). 

The TL and MAK values should be used as guides in the control of health hazards. They are not constants that can be used to draw fine fines between safe and dangerous concentrations. Nor is it possible to calculate the TL or MAK values of solvent mixtures from the data in Table A-13, because antagonistic action or potentiation may occur with some combinations. It should be noted that occupational exposure limits such as the TL and MAK values are not intended for use as a comparative measure of one solvent against another. The values set airborne concentration limits on chemical exposure, but do not describe the ease with which that airborne limit is achieved. In addition, the vapour pressure of the solvent must also be considered. The lower the vapour pressure, the lower the airborne concentration. In order to better compare the safety of volatile compounds such as organic solvents, the use of the vapour hazard ratio ( VHR) has been recommended as a feasible measure [175], The vapour hazard ratio is defined as the quotient of the saturation concentration of a solvent (in mg/m at a given temperature and pressure) and its occupational exposure limit (in mg/m e.g. TL or MAK values), according to ... 

In 1958, Rachel Carson - a trained biologist with a literary flair - began writing Silent Spring, drawing parallels between the hazards of radioactive fallout and chemical pesticides. 

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