Limit, short term requirements

Maximum use concentration (MUC) means the maximum atmospheric concentration of a hazardous substance from which an employee can be expected to be protected when wearing a respirator, and is determined by the assigned protection factor of the respirator or class of respirators and the exposure limit of the hazardous substance. The MUC can be determined mathematically by multiplying the assigned protection factor specified for a respirator by the required QSHA permissible exposure limit, short-term exposure limit, or ceiling limit. When no QSHA exposure limit is available for a hazardous substance, an employer must determine an MUC on the basis of relevant available information and informed professional judgement. 

The impact of the regulations in Table 4 is to require users and producers of VOC ketones to limit release by either reformulating to new solvent systems, to install environmental control systems which recover and recycle solvents, or reduce emissions with carbon absorption beds or incineration equipment. The use of some individual ketones will decline further, but the overall short-term use of ketones is forecast to remain stable (10). 

Effective Dec. 10, 1987, the existing standard for benzene was amended under OSHA (29 CER, Part 1910.1028). The revised standard reduced the permissible exposure limit from 10 ppm (32 mg/m ) to 1 ppm (3.2 mg/m ) iu an 8-h TWA. The short term exposure limit (STEL) of 5 ppm was set over a 15 min period. The standard also established action level requirements for exposure over 0.5 ppm. 

Equipment—client may not have the equipment required to manufacture a specific product. It may be that available capital and installation time are limited such that they simply can not design, acquire, install and test the process equipment to reach the desired capacity within the available budget and time. If a product is in the early stages of its life cycle, the capital required may be hard to justify. This could be based upon the low initial volume anticipated while developing the market or the need to take advantage of a time-sensitive business opportunity. Tolling can provide a means to safely produce introductoiy, short-term, or small volume products that would otherwise be uneconomic. 

Health Hazards Information - Recommended Personal Protective Equipment Filter respirator Symptoms Following Exposure No apparent toxicity General Treatment for Exposure None required Toxicity by Inhalation (ThresholdLimit Value) Data not available Short-Term Inhalation Limits Data not available Toxicity by Ingestion Data not available Late Toxicity Causes central Vapor (Gas) Irritant Characteristics Data not available Liquid or Solid Irritant Characteristics Data not available Odor Threshold Data not available. 

A distinction must be made regarding the length of service of the pressure reducing systems. Fatigue failure of any mechanical system depends on time, i.e., the number of cycles to failure. Therefore, the treatment required for a continuous service may not be justified for a short term service. A System in short term service is defined as one which operates a total of 12 hours or less during the life of the plant. Pressure relief valves typically meet this limit. Systems in short term service exceeding the screening criteria indicated above should be evaluated. 

Long-term exposure limit (LTEL) An exposure limit requirement based on the assumption that the total body intake of a pollutant below this limit over an 8-hour working day will have no harmful effect on the worker over a working life. See also Maximum exposure limit (MEL), Occupational exposure limit (OEL), and Short-term exposure limit (STEL). 

Cluster headache responds to many of the same treatment modalities used in acute migraine however, initial prophylactic therapy is required to limit the frequency of recurrent headaches within a periodic series. A novel therapy specific to cluster headaches is the administration of high-flow-rate oxygen 100% at 5 to 10 L/minute by non-rebreather facemask for approximately 15 minutes.42 If pain is not aborted, then retreatment is indicated. No side effects are seen with short-term oxygen use. If oxygen therapy is not wholly effective, then pharmaceuticals... 

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