Risk Analysis For: ES-317Y and ES Plant Design Project at UWO By: R.A. Hawrelak, P.Eng. - Lecturer Dept of Chem & Biochem Eng’g Dow Chemical – 1960 to 1993

What is Risk Analysis? A risk analysis is any study that identifies hazardous concerns. There are many types of risk analyses (PHA, HAZOP, Dow Fire and Explosion Index, QRA). Two basic methodologies. One is a Deterministic Method and the other is a Probabilistic Method.

Deterministic Methods How far to LEL? How far to second degree burns? How far to 1 psig Overpressure in a VCE (building damage)? How far to ERPG2 - a toxic concentration endpoint for a dispersion.

Probabilistic Method Quantitative Risk Analysis (QRA) What is probability of reaching the LEL at a certain distance? What is probability of receiving second degree burns? What is probability of receiving 1 psig Overpressure from a VCE?

Netherlands Opts For QRA Detailed QRA legislated by law. Permits req’d for all plants. Individual Risk negligible at 1E-08 chance of fatality per year. Societal Risk required to meet specified Guidelines. All companies use SAFETI, a huge, complex computer model.

Dutch Individual Risk

Dutch Societal Risk

Great Britain Opts For QRA Detailed QRA required if HSE deems the plant exceeds certain planning criteria. QRA can be performed by HSE or any recognized risk company. HSE has proposed 1E-06 chance of fatality as a level of risk that would be broadly acceptable to members of the public.

US EPA Opts For A Deterministic Risk Method Risk Management Plan (RMP) became law on 20 June, Worst Case Scenario and Alternative Scenario for each toxic chemical. Only one flammable scenario - Worst Case and Alternative, the one that impacts on the public to the greatest extent.

U.S. RMP Computer Program RMP Manual available with 27 examples or …. Free download of RMP computer program at comp.html comp.html Download it on to your hard disc. It’s very simple to use. If you don’t know your storage quantity yet, run the threshold quantity to see how big a problem you may have. You may decide to store less.

Canada Opts For Guidelines Major Industrial Accidents Council of Canada (MIACC). MIACC modifies Dutch Guide To Hazardous Industrial Activities. A two point probabilistic method using Individual Risk as negligible at 1E-06. Dow Chemical does not accept the two point concept because it is fundamentally flawed (RAH – MIACC rep for Dow).

MIACC Publications Lists of Hazardous Substances Hazardous Substances Risk Assessment: a Mini-Guide for Municipalities and Industry. Risk Assessment Guidelines for Municipalities and Industries - An Initial Screening Tool.

New Canadian Draft Regulation Ottawa, August 20, Industrial Facilities that handle dangerous substances will be required to develop accident prevention plans. e.htmhttp:// e.htm Environmental Emergency (E2) Regulations under Canadian Environmental Protection Act, 1999 (CEPA 1999) Targets an initial list of 174 substances.

What Info Included in E2 Plan? Senior management commitment. Types of on-site and off-site emergencies. A description of individual roles & responsibilities. Contact lists. Training logs. A means for ensuring the plan is current, comprehensive and effective.

E2 Implementation 1500 facilities expected to comply with the proposed regulation. Must develop, implement and test an emergency plan within 1 year of the regulation coming into effect. Regulation is expected to be in place early in 2003.

E2 Submissions E2 plans will not be submitted. Two declarations must be submitted. (1) A declaration that a E2 plan has been prepared and is being implemented. (2) A declaration of implementation indicating that implementation of the E2 plan has been completed.

Info in Declarations Facility data. An indication of whether or not environmental emergency prevention, preparedness, response and recovery measures are identified in the plan. An indication that information from previous environmental emergencies has been incorporated into the plan.

Key References Used in E2 See Appendix 3 in Draft Regulation. Quebec Guide: CRAIM, Risk management for Major Industrial Accidents intended for municipalities and Industry (Based on U.S. RMP). Hazardous Substances Risk Assessment: a Mini-Guide for Municipalities and Industry. (Flawed methodology – RAH).

E-2 Concerns Need to Question the threshold quantity in List of Substances. Concern that smaller quantities may impact on the public in areas where the public is too close to the chemical facility. Concern regarding lack of a permit to operate. The EPA gives a permit to operate based on the RMP program.

RMP Concerns RMP stresses ERPG2 end points for toxic chemicals. This low concentration results in long impact distance for any given dispersion. RMP requires ER planning over a large area which is difficult to plan and manage. RMP does not identify acute hazardous areas closer to the source. These area are extremely vulnerable in short time frames. Use of alternate dispersion models must be qualified against known data points. RMP focus is on storage. More hazardous areas such as reactors are not included (Flixborough).

End of Presentation Good luck on your project. Questions can be asked via at