Significant accidental release

Significant accidental release. Any release of a regulated substance that has caused or has the potential to cause off-site consequences such as death, injury, or adverse effects to human health or the environment, or to cause the public to shelter in place or be evacuated to avoid such consequences. 

Introduction Theprevious sections dealt with techniques for the identification of hazards and methods for calculating the effects of accidental releases of hazardous materials. This section addresses the methodologies available to analyze and estimate risk, which is a function of both the consequences of an incident and its frequency. The apphcation of these methodologies in most instances is not trivial. A significant allocation of resources is necessary. Therefore, a selection process or risk prioritization process is advised before considering a risk analysis study. 

The EPA Accidental Release Prevention Requirements (40 CFR 68) have significant gaps in coverage of reactive hazards. 

Accidental releases of agent or other hazardous materials are expected to be no more likely for a SILVER II plant than for plants using other technologies for destruction of agent. The most significant source of accidental exposure to the public remains the rockets in storage and transport to the chemical demilitarization facility. 

ARIP involves collecting questionnaire information from facilities that have had significant releases of hazardous substances, developing a national accidental release database, analyzing the collected information, and disseminating the results of the analysis to those involved in chemical accident prevention activities. ARIP also helps to focus industry s attention on the causes of accidental releases and the means to prevent them. The database is publicly available and covers incidents from 1986-1999. 

The accidental release of several tons of MIC in 1984 at Bhopal, India, resulted in a very heavy death toll (approximately 1850) and, in survivors, significant impairment of health. Immediate symptoms were difficulty in breathing, skin and eye irritation, vomiting, and unconsciousness. Only a few deaths were recorded in the first few hours, with the maximum number of fatalities occurring between 24 and 72 hours. The predominant cause of death was cardiac arrest following severe pulmonary edema. Lung function abnormalities have persisted years after exposure. Ophthalmic effects included lacrimation, lid edema, photophobia, and ulceration of the corneal epithelium. A follow-up study 3 years after exposure showed excess irritation, eyelid infection, cataract, and a decrease in visual acuity, but corneal erosion was resolved. ... 

Petroleum facilities may accidentally release significant quantities of arsenic into soils, sediments, and waters. Soils surrounding a crude oil storage facility in Los Angeles, California, USA, normally contain <0.5-8.0mg kg-1. However, the soils were contaminated with 30-2300mg kg-1 of arsenic. Most of the arsenic probably originated from corrosion inhibitors that were used in production wells and possibly also from arsenic-bearing biocides that were applied to tanks (Wellman, Reid and Ulery, 1999). 

In all cases, it is important to appropriately safeguard public health without defaulting to overly conservative actions (e.g. to nondetect ) that would divert limited resources without significant benefit. The following sections summarize toxicological support and developmental rationale for the two primary criteria of interest to community decision-makers managing response to an intentional or accidental release of nerve agent(s) to the environment. 

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