Liquids toxic endpoints

Not specifically listed in the OSHA standard and are flammable liquids or gases, but a 10,000-pound Threshold Quantity probably would be considered excessively hazardous because of the toxicity hazard, as indicated by low values for the EPA Toxic Endpoint [A-9] or for the IDLH. 

In brief, the PEEP index is a useful HAS to apply in comparative studies of wastewater effluents to assess their ecotoxicity and toxic loading. Some of its advantages include the fact that it considers results from different toxicity tests and endpoints, while integrating all possible antagonistic, additive or synergistic interactions that can occur between toxicants in a complex liquid sample. Furthermore, the use of a single PEEP value becomes very useful for decisionmakers who are then able to take science-based decisions to prioritize corrective actions on industries whose effluents are the most toxic for the aquatic environment. It is also noteworthy to point out that the PEEP index can be applied anywhere with any number or type of tests and endpoints to suit the needs and expertise of laboratories internationally. 

The sample dilution principle employed in the pT-scale improves the determination of toxic hazard potentials of sediment samples over that of effect percentages reported for undiluted test samples. For instance, a 100% effect measured with a specific endpoint and produced by undiluted samples may become undetectable after a dilution of 1 2 or after much higher dilutions. Clearly, it is essential to know the dilution level at which a whole sediment (or one of its liquid phases) ceases to be toxic1. In this respect, the pT-dilution approach offers valuable information allowing sediments to be more accurately classified in terms of the magnitude of toxicity. 

The EPA standard does not require an off-site consequence analysis for pool fires unless the thermal-radiation endpoint (5 kilowatts/m ) is outside the property boundary, or unless there are locations within the property boundary to which the public has routine and unrestricted access during or outside business hours. If either of these situations could exist, the EPA standard recommends that the consequences of a pool fire be evaluated as an alternative scenario for a flammable-liquid release and be described in terms similar to those listed under Toxicity Hazards. 

For the worst-case scenario for a flammable substance, the modeling assumes either a vapor cloud explosion or BLEVE. The endpoint distance for a vapor cloud explosion is 1 psi over pressure. For a BLEVE, the distance is at 5 kw/m for 40 seconds, or a thermal equivalent to receive second degree burns. For a worst-case release scenario involving toxic gas, the modeling is based on aU of the gas released in 10 minutes. For a worst-case release scenario involving a liquid that evaporates, the modeling may be for a 10-minute or 60-minute release duration. 

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