Document M4D0QXk4OwYn3ajbNqLM148r9
i
SEPTEMBER 1993 Second Edition
...............................
*0 A 029438 CONFIDENTIAL.
TABLE OF CONTENTS
Page Preface...................................................................................................................................................... i
Introduction ..................................................................................................... ....................................... 1
Procedure for Chemical Exposure Index Calculations.................................................................. 2
Scenarios for Estimation of Airborne Release Rates...................................................................... 4
Emergency Response Planning Guidelines (ERPG) and Dow Emergency Exposure Planning Guideline (EEPG) .................................................................................................................
5
Guidelines for Estimating the Amount of Material Becoming Airborne Following a
8
Release......................................................................................................................................................
Estimating the Airborne Quantity for Gas Releases....................................................................... 11
Estimating Airborne Quantity for Liquid Releases......................................................................... 12
CEI and Hazard Distance Calculation ............................................................................................... 16
Chemical Exposure Index Summary Form....................................................................................... 20
Figures Figure 1 -- Procedure for Calculation of Chemical Exposure Index (CEI) ...................... Figure 2 -- Flowchart for Calculating the Airborne Quantity .............................................. Figure 3A -- CEI vs. Airborne Quantity (SI Units)................................................................ Figure 3B -- CEI vs. Airborne Quantity (US/Brit Units) .....................................................
3 10 18 19
Tables Table 1 -- Emergency Response Planning Guidelines: ERPGs/EEPGs............................ Table 2A -- Physical Property Table for CEI (SI Units) ...................................................... Table 2B -- Physical Property Table for CEI (US/Brit Units).............................................
6 21 22
Appendices Appendix 1 --Chemical Exposure Index Review Process.................................................... Appendix 2 -- Containment and Mitigation Checklist............................................................ Appendix 3 --Example CEI Calculations (4 examples)........................................................ Appendix 4 --Chemical Exposure Index for Selected Chemicals for Releases................. for Releases from a 2-inch Diameter Hole
23 26 27 38
DO A 029439 CONFIDENTIAL
PREFACE: CHEMICAL EXPOSURE INDEX GUIDE
Background
As a result of various petrochemical incidents occurring in the mid-1980s, the first edition Chemical Exposure Index Guide (CEI) was developed and published in May 1986. Along with the Fire and Explosion Index Hazard Classification Guide (F&EI), these two guides have served as a relative ranking analysis to evaluate the hazard potential of installations or changes to installations associated with our facilities.
Corporate Minimum Requirements
The CEI and F&EI guides are a requirement of the Dow Corporate Minimum Requirements for Safety, Loss Prevention and Security (June 1989,4th Edition).
Industry and Governmental Availability
The CEI and F&EI have been made available to all interested parties through the American Institute of Chemical Engineers (AIChE), 345 East 47 Street, New York, NY 10017 (Phone 212-705-7657). In fact, various countries (The Netherlands and the United States) have referenced the F&EI and CEI guides in their respective governmental regulations.
Second Edition Improvements
The following improvements have been incorporated into the second edition of the CEI:
1. The new CEI methodology utilizes a linearized expression (rather than a step function) for estimating airborne quantity released. The new methodology provides an index that is consequence based and is independent of the frequency of events. This results in an index that is suited for use as a screening tool for more sophisticated process hazard analyses. These analyses are outlined in the Corporate Process Risk Management Guidelines for Facilities and Distribution. A CEI greater than 200 for facilities will require further risk review.
2. Since the CEIs will now function as a screening tool for further analysis, it was necessary to standardize the scenario selection to ensure consistency on a global corporate basis.
3. A comprehensive review process has been included
This guide is a completely revised document including a new methodology for determining the CEI. Because the new methodology is continuous in many of the variables, the scale for the new CEI is completely different from the earlier version. CEI values from the May 1988 Edition cannot be com pared to the CEI value calculated by the procedure described here.
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CONFIDENTIAL
INTRODUCTION: CHEMICAL EXPOSURE INDEX
The Chemical Exposure Index (CEI) provides a simple method of rating the relative acute health hazard potential to people in neighboring plants or communities from possible chemical release incidents. Absolute measures of risk are very difficult to determine, but the CEI system will provide a method of ranking one hazard relative to another. It is NOT intended to define a particular design as safe or unsafe. All Dow facilities storing or handling acutely toxic materials are expected to calculate the Chemical Exposure Index. This includes new projects as well as existing facilities. The CEI is used: For conducting an initial Process Hazard Analysis (PHA). The requirements for further analysis based
on CEI are described in the Process Risk Management Guidelinesfor Facilities and Distribution. In the Distribution Ranking Index (DRI) calculations (Refer to Corporate S/LP/S, Guidelines for
Determining the Distribution Ranking Index). By all locations in their review process, which provides the opportunity to make recommendations for
eliminating, reducing or mitigating releases. In Emergency Response Planning. Please note that the flammability and explosion hazards are not included in this index. There are other process hazard analysis methods used to identify and measure flammability and explosion hazards. (Refer to Corporate S/LP/S publication, Fire and Explosion Index Hazard Classification Guide.)
Do COfyp1
SCENARIOS FOR ESTIMATION OF AIRBORNE RELEASE RATES
The purpose of scenario selection is to determine which process piping or equipment has the greatest potential for the release of significant quantities of acutely toxic chemicals. Since the CEI now serves as a screening tool for further process hazards analysis, it is important that the calculations be done consistently on a global basis. The scenario selection process for determining airborne release rate has, therefore, been standardized to help achieve this goal. The selections listed below were chosen to include the most probable credible events based on historical performance of the chemical industry.
Evaluating several scenarios will aid in determining the largest potential airborne release. Process conditions such as temperature, pressure and physical state should be considered as well as pipe size since they have a significant impact on airborne release rates.
Scenario Selection for CEI: Select the scenario that gives the largest airborne release.
1. PROCESS PIPES Rupture of the largest diameter process pipe as follows:
For smaller than 2-inch diameter -- full bore rupture
For 2- through 4-inch diameter -- rupture equal to that of 2-inch diameter pipe For greater than 4-inch diameter -- rupture area equal to 20% of pipe cross section area
2. HOSES Full bore rapture
3. PRESSURE RELIEF DEVICES RELIEVING DIRECTLY TO THE ATMOSPHERE Calculated total release rate at set pressure. Refer to pressure relief calculation or contact process engineering. All material released is assumed to be airborne.
4. VESSELS Rupture based on largest diameter process pipe attached to the vessel using pipe criteria above.
5. TANK OVERFLOWS AND SPILLS
6. OTHERS Scenarios can be established based on the plant's or technology's experience, they can be the outcome of a review or derived from hazard analysis studies. They can also be based on the experience of another technology if the event could occur in this unit. Contact Process Engineering for special cases that may include reactivity or mixtures.
The treatment of instantaneous and very short duration continuous releases is simplified for the CEI calculation. Release from all scenarios are assumed to continue for at least a five minute duration. If a release is instantaneous or exceeds the total inventory within this duration, the release rate is calculated by dividing the total inventory by five minutes.
After this evaluation, choose the largest airborne release rate for the CEI calculation (page 20).______________________________________________
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EMERGENCY RESPONSE PLANNING GUIDELINES (ERPG) AND DOW EMERGENCY EXPOSURE PLANNING GUIDELINES (EEPG)
The American Industrial Hygiene Association (AIHA) has published Emergency Response Planning Guidelines (ERPG) values which are intended to provide estimates of concentration ranges where one might reasonably anticipate observing adverse effects.
These guidelines are intended to be used as a planning tool for various Dow programs to determine priority concerns, to evaluate the adequacy of containment, to identify downwind areas which might need to take action during a release and to develop community emergency response plans. The need for an ERPG is based cm the volatility of a chemical, its toxicity, the releasable quantity and the public's perception of the potential hazard.
The Emergency Exposure Planning Guidelines (EEPGs) are the Dow equivalent to the AIHA published ERPGs. These are provided when AIHA ERPGs do not exist. ERPG/EEPG definitions are as follows:
ERPG-l/EEPG-1 is the maximum airborne concentration below which it is believed that nearly all individuals could be exposed for one hour without experiencing other than mild transient adverse health effects or perceiving a clearly objectionable odor.
ERPG-2/EEPG-2
is the maximum airborne concentration below which it is believed that nearly all individuals could be exposed for up to one hour without experiencing or developing irreversible or other serious health effects or symptoms that could impair their abilities to take protective action.
ERPG-3/EEPG-3 is the maximum airborne concentration below which it is believed that nearly all individuals could be exposed for up to one hour without experiencing or developing life-threatening health effects.
D0 A 029443 CONFIDENTIAL.
TABLE 1 EMERGENCY PLANNING GUIDELINES: ERPGs/EEPGs
Material
Acetone cyanohydrin * Acrolein Acrylic acid Acrylonitrile * Allyl chloride Ammonia Bromine Butadiene n-butyl acrylate n-butylisocyanate Carbon disulfide jlGarboinetochlorids fcWonng Chlorine trifluoride Chloroacetyl chloride Chloroform * Chloropicrin Chlorosulfonic acid Chlorotrifluoroethylene Crotonaldehyde Diketene Dimethylamine Epichlorohydrin Ethyl chloride * Ethylene dichloride * Ethylene oxide Formaldehyde Hexachlorobutadiene Hexafluoroacetone Hydrogen bromide * Hydrogen chloride Hydrogen cyanide Hydrogen fluoride Hydrogen sulfide 2-isocyanatoethyl methacrylate Isobutyronitrile Methacrylonitrile * Methanol Methylamine Methyl chloride Methyl iodide Methyl isocyanate Methyl mercaptan Perfluoroisobutylene Phenol
Boiling Molecular Point ERPG-1 ERPG-1 ERPG-2 ERPG-2 ERPG-3 ERPG-3
Weight C mg/m3 PPM mg/m3 PPM mg/m3 PPM
85.11 56.06 72.06 53.06 76.53 17.03 159.81 54.09 128.17 99.13 76.14 153.82 70.91 92.50 112.94 119.38 164.38 116.52 116.47 70.09 82.08 45.08 92.52 64.51 98.96 44.05 30.03 260.79 166.02 80.91 36.46 27.03 20.01 34.08 155.20 69.11 67.09 32.04 31.06 50.49 141.94 57.05 48.11 218.11 94.11
95 52.5 141.4 77.2 44.8 -33.3 58.7 -4.41 147.5 115.13 46.3 76.8 -34.05 11.8 106 61.7 115.1 152 -28.22 102.4 127.4 6.88 116.4 12.27 83.51 10.5 -19.3 214.2
-66.7 -85.03
25.7 19.9 -60.4 211.2 103.6 90.31 64.5 -6.32 -24.2 -66.5 38.4 5.95
181.9
6
9 17
1 22 0.26 0.04
3 126
3 0.38
0.5
2 95
6 3 2 8
1 32
4
4 0.14
28
262 13
145 0.058
0.01
38
0.1 2
3 25 0.2 10 0.05 0.01
1 20
1 0.1 0.1
NA 0.4 20
2 1 1 2
NA 1 3
NA
3 NA
5 0.1 NA 10
200 10
NA 25 0.025 0.005 NA 10
35 10
1 0.5 7 3
147
50 2210
750
43 20
125 40 939 300
139 200 696 1000
7 1 33 5
111 50 11060 5000
131
25 1310
250
0.2 0.05 4 1
156
50 1557
500
629 100 4718 750
9 3 58 20
4 1 38 10
5 1 46 10
488 100
1 0.2
20
3
10 2.1
30 6.3
476 100 1429 300
29 10 143 50
17
5 168
50
184 100 922 500
76
20 378
100
13192 5000
405 100
90 50 901 500
12 10 31 25
107 10 320 30
7
1 339
50
17 5
30 20 149 100
11 10 28 25
16 20 41 50
42 30 139 100
1 0.1 6 1
141 50 565 200
27 10
1310 1000 6551 5000
127 100 635 500
826
400 2065
1000
290 50 726 125
1 0.5
12
5
49 25 197 100
1 0.1
3 0.3
192 50 770 200
Reference Temperature 25 C
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TABLE 1 (continued)
Material
Phosgene Phosphorous pentoxide Propylene oxide * Styrene Sulfur dioxide Sulfuric acidi(Sulfur trioxide) Sulfuryl fluoride * Tetrafluoroethylene Titanium tetrachloride Toluene diisocyanate * Trimethylamine Vinyl acetate Vinyl chloride * Vinylidene chloride *
Boiling
Molecular Point ERPG-1 ERPG-1 ERPG-2 ERPG-2 ERPG-3 ERPG-3 Weight C mg/m3 PPM mg/m3 PPM mg/m3 PPM
98.92
7.9
NA
1 0.2
4
1
141.94
5
1 25
4 100
17
58.08 34.2
1188
500
104.15 145.2
213
50 1065
250 4259 1000
64.06
-10
1 0.3
8
3 39 15
98.08
2 0.5
10 2.5
30 7.5
102.06 -55.2
626 150 #
100.02 -75.6 818 200 4090 1000 40902 10000
189.69 217.45
5
1 20
3 100
13
174.16 252.8
1 0.2
59.11 2.87
0.1 242 100 1209 500
86.09 72.76
18
5 264
75 1760
500
62.50 -13.8
2556 1000
96.94 31.7
198 50
NA = Not Appropriate * - Indicates EEPGs
Reference Temperature 25 C
To convert ERPG values from PPM to mg/m3, use the following equation;
ERPG(mg/m3) = SESifiMW 24.45
When established ERPG/EEPG values do not exist, the following approaches for deriving substitute values are recommended:
ERPG-2 (in preferred order)
1. Use the workplace exposure guideline (Dow IHG, ACG1H TLV or AIHA WEEL). a. Use the STEL or ceiling values if one exists. b. Use three times the TWA value.
2. If no workplace guideline exists, contact your industrial hygienist for assistance.
ERPG-3 (in preferred order)
1. LC-50 divided by 30. 2. Use five times the ERPG-2 substitute value
ERPG-1 (in preferred order)
1. Use Odor Threshold value 2. Use ERPG-2 substitute value divided by 10.
Note: ERPG/EEPG values are updated periodically. Contact Corporate Health and Environmental Sciences or Safety and Loss Prevention for most current listing or inclusion of additional chemicals to the list.
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GUIDELINES FOR ESTIMATING THE AMOUNT OF MATERIAL BECOMING AIRBORNE FOLLOWING A RELEASE
This section of the CEI guide provides a description of the method to calculate the airborne quantity. The airborne quantity, as used in this guide, refers to the total quantity of material entering the atmosphere over time, directly as vapor or due to liquid flashing or pool evaporation.
CEI scenarios consider materials to be released as liquid or vapor. For example, the contents of a vessel can escape as a liquid through nozzle A, a vapor through nozzle B or "as calculated" through the relief device attached to nozzle C. Complex calculations that consider two-phase flow from ruptures are not included.
Airborne quantity for vapor releases from nozzle (B) or a pressure relief device (C) is the highest total flow rate calculated given the conditions of the vessel when the release occurs.
Liquid releases require a more complex treatment. As a liquid exits a vessel or pipe as a result of a failure, it can simply run out on the ground forming a pool (see Figure A), partially vaporize forming both a pool and a vapor cloud (see Figure B) or flash to such an extent that all the residual liquid exists as small droplets that are carried away with the vapor (see Figure C).
Figure A
Figure B
Figure C
A simple treatment of these events uses the operating conditions of the process to estimate the behavior of the material after the release.
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Liquids reaching the ground form a pool that spreads according to the terrain. If the vessel is surrounded by a dike, the liquid usually flows to the walls of the dike and the pool assumes the area within the dike. In all other cases, the pool is assumed to have an area that is predicted by the amount of liquid that enters the pool. Once a pool is formed, the liquid begins to evaporate from the surface. The vapor from the pool will combine with the vapor from the original flash and be dispersed downwind. This incident is treated by taking a "picture" of the release at a moment in time and then assuming it does not change. (See Figure D)
The airborne quantity for a liquid spill is deteimined by what happens to the liquid as it leaves the tank. If the liquid flashes to a high degree, then the airborne quantity is the discharge rate from the vessel. But if the liquid flash is low enough to allow pool foimation, the airborne quantity is the gas flow resulting from the flash plus the airborne quantity that evaporates from the pool surface. Finally, as the tendency of the liquid to flash becomes small, the airborne quantity becomes the rate of evaporation from the pool surface. Figure 2 (page 10) provides a simplified flowchart for calculating airborne quantity. The equations are presented in both SI and US/British units.
DO A 029447 CONFIDENTIAL
FIGURE 2 FLOWCHART FOR CALCULATING AIRBORNE QUANTITY
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ESTIMATING THE AIRBORNE QUANTITY FOR GAS RELEASES
The following equations, based on the sonic gas flow rate equation, are used to estimate the airborne quantity for a gas release.
SI Units
where Pa = absolute pressure = (Pg + 101.35) Pg = gauge pressure (kPa gauge) MW = molecular weight of the material T = temperature (C) D = diameter of the hole (millimeters)
{kg/sec}
(Equation 1A)
US/Brit Units
where Pa = absolute pressure = (Pg + 14.7) Pg = gauge pressure (psig) MW = molecular weight of the material T = temperature (F) D = diameter of the hole (inches)
{lb/min}
(Equation IB)
11 DO A 029449 CONFIDENTIAL
ESTIMATING THE AIRBORNE QUANTITY FOR LIQUID RELEASES
The following steps describe a simplified procedure for estimating the airborne quantity for liquid releases.
Step 1: Determine the liquid flow rate being released.
The liquid release rate (L) is given by the following equations:
These equations assume that release from all scenarios will continue for at least five minutes before releases can be stopped. If a five minute release would exceed the total inventory, the release rate is calculated by dividing the total inventory by five minutes.
SI Units
where Pg = gauge pressure (kPa gauge)
(Note:for a tank open to the atmosphere Pg = 0) pj = density of the liquid at operating temperature (kg/m3) Ah - height of the liquid above the release point (meters) D = diameter of the hole (millimeters) US/Brit Units
where Pg = gauge pressure (psig)
(Note:for a tank open to the atmosphere Pg = 0) pj = density of the liquid at operating temperature (lb/ft3) Ah = height of the liquid above the release point (feet) D = diameter of the hole (inches)
{kg/sec}
(Equation 2A)
{IbAnin}
(Equation 2B)
12
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Step 2: Determine the total liquid released.
The total amount of material contributing to the pool formation must be estimated in order to determine the pool size. If a release is large enough to empty a vessel in less than 15 minutes (including very large releases that occur in less than 5 minutes), the mass of liquid entering the pool is the total inventory of the vessel. For a longer duration continuous release (one lasting more than 15 minutes) the pool is assumed to reach a final size after 15 minutes. In this case, the mass determining the pool size is the release rate times 15 minutes (900 seconds).
The total liquid release (Wx) is the tank inventory (the tank is emptied in less than 15 minutes) or given by:
SI Units
Wx = 900 L
{kg}
(Equation 3A)
where
L = liquid flow rate (kg/sec)
US/Brit Units
Wx = 15 L
{lb} (Equation 3B)
where
L = liquid flow rate (lb/min)
Compare the calculated Wt to the inventory of the system involved in the release. The total liquid assumed to be involved in the release is taken as the smaller of these two values.
WT = smaller of calculated Wx or system inventory
Step 3: Calculate the fraction flashed.
Compare the operating temperature of the liquid to its normal boiling point. If the temperature is less than the normal boiling point, the flash fraction is zero. Go to Step 4, Equation 6. If the temperature is greater than the normal boiling point, calculate the fraction flashed (Fv).
The fraction of the liquid that will flash (Fv) when released is given by: Fv=^-(TS-Tb)
Hv
where
Tb = normal boiling point of the liquid Ts = operating temperature of the liquid Cp = average heat capacity of the liquid Hv = heat of vaporization of the liquid
SI
c c
J/kg/C J/kg
(Equation 4)
US/Brit F F
BTU/lb/F BTU/lb
The CEI data table contains the ratio of heat capacities to latent heats of vaporization (Cp/Hv) for many chemicals. If a chemical is not listed and the needed information cannot be found, then a value of 0.0044 (SI) or 0.0024 (US/Brit) may be used for the ratio Cp/Hv.
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As flashing occurs, some liquid will be entrained as droplets. Some of the droplets are quite small and travel with the vapor while the larger droplets fall to the ground and collect in a pool. As an approxima tion, the amount of material staying in the vapor is five times the quantity flashed. Therefore, if 20% of the material flashes, the entire stream becomes airborne and there is no pool formed.
The airborne quantity produced by the flash (AQf) is given by:
AQf = 5 (Fv) (L)
{kg/sec or lb/min}
(Equation 5)
where L = liquid flow rate (kg/sec or lb/min) If Fv > 0.2 then AQf = L and no pool is formed. Proceed to Step 6.
Step 4: Determine the pool size. The total mass of liquid entering the pool (Wp) is given by:
Wp = WT (1 - 5FV)
{kg or lb)
(Equation 6)
where
Wt = total liquid released (kg or lb) Fv = fraction flashed
Please note that if none of the material flashes,
Wp = WT (kg or lb)
The size of the pool is approximated by assuming a pool depth of one centimeter. If the spill is in a diked area and of sufficient size, then the pool size is equal to the diked area.
The pool area (Ap) is given by:
SI Units
Pool Area (Ap) = 100--E-
Pi
{m2}
(Equation 7A)
where
Wp = total mass entering the pool (kg) pj = density (kg/m3)
US/Brit Units
Pool Area (Ap) = 30.5--E-
Pi
{ft2}
(Equation 7B)
Wp = total mass entering the pool 0b) pj = density Ob/ft3)
14
If the liquid falls into a diked containment area, then the pool size may be equal to the diked area minus the area taken up by the tank. But, if the spill does not fill the diked area or occurs outside the diked area, use Ap.
Step 5: Determine the airborne quantity evaporated from the pool surface.
Airborne Quantity evaporated from the pool surface (AQp) is given by:
SI Units AQp = 9.0x10^(ap-95)(MW)Pv T 273
{kg/sec}
where
Ap = pool area (m2) MW = molecular weight Pv = vapor pressure of the liquid at the characteristic pool temperature (kPa) T = characteristic pool temperature (C) (see Conditions 1 and 2)
(Equation 8A)
US/Brit Units AQp = 0.154(Apa95)^p^^
{lb/min}
(Equation 8B)
where
Ap = pool area (ft2) MW= molecular weight Pv = vapor pressure of the liquid at the characteristic pool temperature (psi) T = characteristic pool temperature (F) (see Conditions 1 and 2)
Condition 1 If the liquid is at or above ambient temperature but below its normal boiling point, the characteristic pool temperature is equal to the operating temperature.
Condition 2 If the liquid is at or above its normal boiling point, the characteristic pool temperature is the normal boiling point of the liquid. The normal boiling point is the boiling point of the liquid at atmospheric pressure.
Step 6: Calculate the total airborne quantity. The total airborne quantity (AQ) is calculated by:
AQ = AQf + AQp
{kg/sec or lb/min} (Equation 9)
where
AQf = airborne quantity resulting from the flash (kg/sec or lb/min) AQp = airborne quantity evaporating from the pool surface (kg/sec or lb/min)
If the total Airborne Quantity (AQ) is greater than the liquid flow rate (L), set AQ = L.
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CEI AND HAZARD DISTANCE CALCULATION Chemical Exposure Index
All CEI calculations assume a windspeed of 5 m/sec (11.2 miles/hour) and neutral weather conditions. The Chemical Exposure Index (CEI) is given by: SI Units
(Equation 10A) where AQ = airborne quantity (kg/sec) ERPG-2 = value (mg/m3) US/Brit Units
(Equation 10B) where AQ = airborne quantity (Ib/min) ERPG-2 = value (PPM) MW = molecular weight If the CEI calculated value is greater than 1000, set CEI = 1000.
16 DO A 029454
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Hazard Distance
The Hazard Distance (HD) is the distance to the ERPG-1, -2 or -3 concentration and is derived from the following equation:
SI Units
{meters}
(Equation 11 A)
where
AQ = airborne quantity (kg/sec) ERPG = ERPG-1, ERPG-2 or ERPG-3 (mg/m3)
US!Brits Units
HD = where
AQ ERPG(MW)
(feet)
(Equation 1 IB)
AQ = airborne quantity (lb/min) ERPG = ERPG-1. ERPG-2 or ERPG-3 (PPM) MW = molecular weight
If HD is greater than 10,000 meters (32,800 feet), set HD = 10,000 meters (32.800 feet).
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CHEMICAL EXPOSURE INDEX SUMMARY
PlantLocation ChemicalTotal Quantity In Plant Largest Single Containment Pressure Of ContainmentTemperature Of Containment _
1. Scenario Being Evaluated _________ 2. Airborne Release Rate from Scenario
3. Chemical Exposure Index
kg/sec lb/min
4.
Concentration
Hazard Distance
mg/m3
PPM
meters
feet
ERPG-l/EEPG-1 ERPG-2/EEPG-2 ERPG-3/EEPG-3
5. Distances to:
Public (generally considered Dow property line) Other in-company facility Non-company plant or business
meters _________ _________ _________
feet _________ _________ _________
6. The CEI and the Hazard Distance establish the level of review needed as determined in the Dow Process Risk Management Guidelinesfor Facilities and Distribution.
7. If further review is required, complete Containment and Mitigation Checklist (Chemical Exposure Index Guide, 2nd Edition - Appendix 2, page 26) and prepare Review Package.
8. List any sights, odors or sounds that might come from your facility and cause public concern or inquir ies (e.g., smoke, large relief valves, odors below hazardous levels such as mercaptans or amines, etc.)
Prepared by:______________________________________ Reviewed by: _____________________________________
Plant Superintendent or Manager Site Review Representative Additional Management Review
(if required)
FumC-91720 (471-00099) Rev. 9/93
______________ ______________ ______________
20
Date
TABLE 2A PHYSICAL PROPERTY TABLE FOR CEI (SI UNITS)
Chemical
Molecular Weight
Boiling Point
C
Vapor Pressure
kPa
Liquid Density @25 C @ BP
kg/m3 kg/m3
Gas Density @ 25 C kg/m3
Ratio of Cp/Hv 1/C
Acrolein Acrylic acid Acrylonitrile Allyl chloride Ammonia Benzene Bromine Butadiene Carbon disulfide Carbon monoxide (BffiaaaBtracMltgidfe. tOhlatiUR Chloroacetyl chloride Chloroform Chloropicrin Chlorotrifluoroethylene Crotonaldehyde Dimethylamine Epichlorohydrin Ethyl chloride Ethylene dichloride Ethylene oxide Hydrogen bromide Hydrogen chloride Hydrogen cyanide Hydrogen fluoride Hydrogen sulfide Methacrylonitrile Methanol Methylamine Methyl chloride Methyl mercaptan Phenol Phosgene Propylene oxide Styrene Sulfuryl fluoride Sulfur dioxide Sulfur trioxide Toluene diisocyanate Trimethylamine Vinyl acetate Vinyl chloride Vinylidene chloride
56.06 72.06 53.06 76.53 17.03 78.11 159.81 54.09 76.14 29.01 153.82 70.91 112.94 119.38 164.38 116.47 70.09 45.08 92.52 64.51 98.96 44.05 80.91 36.46 27.03 20.01 34.08 67.09 32.04 31.06 50.49 48.11 94.11 98.92 58.08 104.15 102.06 64.06 80.06 174.16 59.11 86.09 62.50 96.94
52.5 141.4 77.2 44.8 -33.4 80.1 58.7
AA 46.3 -191.5 76.8 -34.0 106.0 61.7 112.0 -28.2 102.4
6.9 116.4
12.3 83.5 10.5 -66.7 -85.0 25.7 19.6 -60.3 90.3 64.5 -6.3 -24.1
6.0 181.9
7.5 34.2 145.2 -55.2 -10.0 44.4 252.9
2.9 72.8 -13.8 31.7
35.866 0.539 13.900
48.480 1002.800
12.690 28.375 281.090 48.120 2807.000 15.162 778.340
3.330 26.175
3.356 641.260
4.787 205.460
2.279 159.950
10.590 174.010 2358.800 4773.100 98.780 122.740 2020.800
9.477 16.950 348.440 576.540 201.820 0.055 189.900 71.670 0.841 1747.100 392.850 35.688 0.002 221.160 15.280 395.140 79.517
834.4 1046.0 801.0 931.4 602.3 869.8 3105.0 614.9 1256.0
1585.0 1399.0 1412.0 1480.0 1648.0 1290.0 848.9 649.7 1175.0 892.1 1246.0 866.8 1762.0 805.2 679.6 981.5 767.3
794.9 786.0 655.2 915.7 858.6 1070.0 1360.0 823.2 901.6 1318.0 1353.0 1904.0 1211.0 624.8 924.7 902.1 1203.0
684.0
651.0
1562.0
1472.0 671.0 910.0 887.0 2199.0 1188.0 679.0 991.0 929.0
694.0 1014.0 884.0 1403.0
1702.0 1444.0
653.0 972.0
7.79
6.69
25.07
35.13 3.96 4.40 3.25
95.46 113.0
1.14 1.15 34,30
4.66 13.12 4.12 7.96
97.38 10.86
5.68 10.90
4.01E-03
5.92E-03
3.87E-03
7.98E-03 4.89E-03 4.31E-03 3.65E-03 5.66E-03 9.81E-03 2.83E-03 4.24E-03 5.26E-03
3.92E-03 4.19E-03 3.87E-03 4.32E-03
9.57E-03 3.91E-03
6.15E-03 3.88E-03
DO A 029459 CONFIDENTIAL
TABLE 2B PHYSICAL PROPERTY TABLE FOR CEI (US/BRIT UNITS)
Chemical
Molecular Weight
Boiling Point
F
Vapor Pressure
psia
Liquid Density
@77 F @ BP
lb/ft3
lb/ft3
Gas Density @77 F lb/ft3
Ratio of Cp/Hv i/f
Acrolein Acrylic acid Acrylonitrile Allyl chloride Ammonia Benzene Bromine Butadiene Carbon disulfide Carbon monoxide Cjffljotuetfachlorid^ Chlprin& Chloroacetyl chloride Chloroform Chloropicrin Chlorotrifluoroethylene Crotonaldehyde Dimethylamine Epichlorohydrin Ethyl chloride Ethylene dichloride Ethylene oxide Hydrogen bromide Hydrogen chloride Hydrogen cyanide Hydrogen fluoride Hydrogen sulfide Methacrylonitrile Methanol Methylamine Methyl chloride Methyl mercaptan Phenol Phosgene Propylene oxide Styrene Sulfuryl fluoride Sulfur dioxide Sulfur trioxide Toluene diisocyanate Trimethylamine Vinyl acetate Vinyl chloride Vinylidene chloride
56.06 72.06 53.06 76.53 17.03 78.11 159.81 54.09 76.14 29.01 153.82 70.91 112.94 119.38 164.38 116.47 70.09 45.08 92.52 64.51 98.96 44.05 80.91 36.46 27.03 20.01 34.08 67.09 32.04 31.06 50.49 48.11 94.11 98.92 58.08 104.15 102.06 64.06 80.06 174.16 59.11 86.09 62.50 96.94
126.5 286.5 171.0 112.6 -28.0 176.2 137.7
24.0 115.3 -312.7 170.2 -29.2 222.8 143.1 233.5 -18.8 216.3 44.4 241.5
54.1 182.3 50.9 -88.1 -121.1 78.3 67.3 -76.5 194.6 148.1 20.6 -11.4 42.7 359.4 45.5 93.6 293.4 -67.4
14.0 111.9 487.2 37.2 163.0
7.1 89.1
5.201 0.078 2.016 7.030 145.408 1.840 4.114 40.759 6.978 407.022 2.199 112.861 0.483 3.795 0.487 92.984 0.694 29.792 0.330 23.193 1.536 25.232 342.032 692.111 14.323 17.798 293.021 1.374 2.458 50.525 83.600 29.264 0.008 27.536 10.392 0.122 253.334 56.964 5.175 0.000 32.069 2.216 57.296 11.530
52.1 65.3 50.0 58.1 37.6 54.3 193.8 38.4 78.4
99.0 87.3 88.2 92.4 102.9 80.5 53.0 40.6 73.4 55.7 77.8 54.1 110.0 50.3 42.4 61.3 47.9 49.6 49.1 40.9 57.2 53.6 66.8 84.9 51.4 56.3 82.3 84.5 118.9 75.6 39.0 57.7 56.3 75.1
42.7
40.6
97.5
91.9 41.9 56.8 55.4 137.3 74.2 42.4 61.9 58.0
43.3 63.3 55.2 87.6
106.3 90.1
40.8 60.7
0.49
0.42
1.57
2.19 0.25 0.27 0.20 5.96 7.05 0.07 0.07 2.14
0.29 0.82 0.26 0.50
6.08 0.68
0.35 0.68
2.23E-03
3.29E-03
2.15E-03
4.43E-03 2.72E-03 2.40E-03 2.03E-03 3.14E-03 5.45E-03 1.57E-03 2.36E-03 2.92E-03
2.18E-03 2.33E-03 2.15E-03 2.40E-03
5.32E-03 2.17E-03
3.41E-03 2.16E-03
DO A 029460 ___ CONFIDENTIAL _
APPENDIX 1 CHEMICAL EXPOSURE INDEX REVIEW PROCESS
The following is a recommended procedure for the CEI review process.
When a plant or facility requires a further review, they should notify the site Loss Prevention contact and agree to an appropriate review schedule.
The review process should have three elements: 1. A Pre-Review Working Session 2. The Chemical Exposure Index Review Package 3. The Formal Review
Pre-Review Working Session
A one to two hour working session at least two weeks prior to the formal review is strongly recommended.
Purpose: This preliminary working session would let the actual review focus on what can and will be done to eliminate, reduce and/or mitigate potential releases.
This woiking session should have the following suggested agenda:
1. Review each chemical scenario, lines of defense, mitigation measures and plans for improvement with review team.
2. Discuss any past releases of acutely toxic material. ^ 3. Interview an operator in the plant
This interview should focus on the operator's awareness of the Chemical Exposure Index scenarios, use of emergency procedures and specific personal concerns related to the potential release of toxic chemicals. 4. Conduct a drill of a hypothetical CEI release scenario. This drill should be conducted by plant personnel with CEI review team members present and should be designed to evaluate the response to an emergency situation involving a major release of one of the chemicals with the largest CEI. ^ 5. Inspect equipment and piping related to each scenario with the largest CEI. This inspection will consider the condition of pipe and equipment, location of valves and mitigating devices, etc. Mi 6. Review documentation pertaining to each CEI scenario. The following documents are suggested as a minimum: Past hypothetical exercise reports Area monitoring system records Maintenance checklists Operating Discipline including: loading/unloading procedures, shutdown for releases, mitiga
tion procedures, spill reporting procedure, etc. Completeness and quality will be used as a criterion for evaluating the documentation.
-j Written reports of the interview, drill, site inspection and documentation review should be prepared.
DO A 029461 23 CONFIDENTIAL.
Chemical Exposure Review Package
At least one week before the review, the following information should be sent to each member of the review team:
1. Chemical Exposure Index Summary sheets for all chemicals and scenarios calculated.
2. A simplified process flowsheet for areas with chemicals having the largest CEIs.
Include: a) all vessels including description, designation, (i.e., storage tank VT-100) size and normal contents.
b) associated piping including size, approximate length between equipment and any automated block valves.
3. A description of the scenario for each chemical that results in the largest CEIs. Include: a) description of any major changes made to this system since the last audit b) description of the lines of defense or actions to be taken if each scenario occurs. c) description of any mitigation methods, including size of spill areas or dike areas.
4. An area map showing three circles that represent the hazard distance for ERPG-1, -2 and -3 concentrations.
5. A plot plan showing the location of gas monitors, spill detectors or other devices used to detect releases. Also include the type of device used to detect the release and the detection level for each type of device.
6. A completed containment and compliance checklist. 7. A list of the recommendations made in the previous review and the status of each recommendation. 8. A written report for the hypothetical exercise based on one of the Chemical Exposure Index
scenarios. Include a description of the hypothetical release, a chronological list of actions taken and any recommendations for improvement. Include time it took to isolate the release. Note: If the hypothetical exercise is to be done during the review, please include the written description of the exercise scenario in the package. 9. Written results of the employee interview. 10. A written report of the in-plant inspection of each Chemical Exposure Index scenario source site.
If a pre-review working session was not held, these last two items must be provided during the formal review.
Formal Review
The following four activities should be done prior to formal presentation if a pre-review working session was not held:
1. Hypothetical exercise
2. Employee interview
3. Site inspection of each scenario site 4. Documentation review
Suggested Review Agenda
1. Summarize the status of the recommendations made in the previous review.
2. Discuss incidents that have occurred involving chemicals being reviewed.
Include Spill History - incident reports and plant follow-up reports. 3. Summarize the results of CEI calculations. Include hazard distances for ERPG-1, -2, -3.
24 DO A 029462 CONFIDENTIAL.
4. Review the release scenarios for the largest CEIs. Include plot plan showing hazard distances. Address the following items for each scenario: a. Have there been any major changes or additions to this system since the last audit/assessment? b. Discuss your lines of defense that would prevent this scenario release from occurring. c. Discuss the mitigation procedures for each scenario.
5. Discuss results of hypothetical exercise held prior to audit. 6. Discuss results of employee interview held prior to audit. 7. Review results of site inspection of each CEI scenario sources site. 8. Discuss results of documentation review. 9. Discuss your plant's CEI related concerns generated from the audit/assessment preparation. 10. Discuss your plans for improving your operations from a CEI standpoint. 11. Are there any other specific concerns which should be addressed but were not identified in the CEI
review?
A written response including action to be taken, person assigned, anticipated completion date should be reported to the Line Management and the Review Chairman within 45 days and maintained with your Chemical Exposure Index calculations.
25
00 A
CoNFTD
0S9463 htiAl
APPENDIX 2 CONTAINMENT AND MITIGATION CHECKLIST
This checklist is a Process Hazard Analysis tool for evaluating a facility's mitigation features to prevent, detect or control potential releases of acute toxic substances.
The management of any plant or facility requiring review should complete this checklist as part of the preparation for a Chemical Exposure Index review. Please check those that are complete, operational or in compliance with known company rules, guidelines or requirements. Any item that cannot be checked should be marked with the percentage of completion. Be prepared to discuss plans for any item not completed.
Complete (Q______ Risk Reducing Factors
__________
__________ __________ __________
__________ __________ __________
__________
__________
1. All pressure vessel and relief device systems properly registered and inspection up to date and documentation complete. (No expansion joints or glass devices.)
2. All hoses inspected and tested regularly.
3. All operational controls and systems designed and routinely tested to "fail-safe."
4. Critical Instrument Program up to date (e.g., redundant high level and temperature alarms, shutdowns, etc.)
5. Operating Discipline complete and up to date.
6. Vapor Detectors properly placed and tested regularly.
7. Appropriate engineering specifications properly applied (e.g., lethal service, welded fittings, etc.)
8. Are relief vents on toxic containers designed to minimize atmospheric emissions? (per Environmental Protection Guidelines for Operations) How? (circle) Scrubber, Flare or
9. Failure analysis and nondestructive testing carried out where needed (e.g.. X-ray, vibration analysis or monitoring, acoustical emission, piping flexibility - hot and cold).
__________ __________
__________
10. Physical barriers in place (for traffic, cranes, etc.) 11. Designed for excess pressure, if needed (e.g., pipelines in certain areas, tank cars,
trucks, etc.). 12. All personnel properly trained to understand hazards and emergencyresponses.
__________
__________ __________ __________ __________ __________ __________ __________
13. Emeigency Procedures (relating to this exposure potential) in place and annual drill held.
14. Safety Rules and Safety Standards regularly reviewed and enforced. 15. Loss Prevention Principles and Minimum Requirements appropriatelyapplied. 16. Technology Center Guidelines appropriately incorporated. 17. Reactive Chemical Review complete and up to date. 18. Loss Prevention Audit complete and up to date. 19. Technology Center Audit complete and up to date. 20. All new operations and modifications underwent safety pre-startup audit.
__________
21. Management of Change procedures written and utilized.
Reviewed by:
Completed by: Date: 26
DO A 029464 CONFIDENTIAL
APPENDIX 3
EXAMPLE CEI CALCULATIONS
CHLORINE VAPOR RELEASE
The 3/4 inch vapor connection on a 1 ton chlorine cylinder stored at ambient temperature (30 C or 86 F) has broken.
Needed information:
Pressure inside the cylinder, Pg Absolute Pressure, Pa Molecular Weight, MW Storage Temperature, T Diameter of Hole, D
SI 788.1 kPa gauge
889.5 kPa 70.91 30 C 19 mm
US/Brit 114.3 psig 129.0 psia 70.91
86 F 0.75 in
Determine Airborne Quantity. SI Units (Equation IA)
AQ = 4.751 x 10"6 D2 Pa. 1 J^ y (T+273)
AQ = 4.751xl0-W(889.S)!30+ 273)
US/Brit Units (Equation IB) AQ = 3.751D'o Pa ^1 M+4W59)
AQ = 0.74 kg/sec
AQ = 98.2 lb/min
Calculate the CEI. SI Units (Equation 10A)
where ERPG-2 = 9 mg/m3
US/Brit Units (Equation 10B) where ERPG-2 = 3 PPM
CE1655.1J Y ERPG-2
CEI = 281.8,1--------- ^-------- V (ERPG-2)(MW)
CEI = 655.1 J-- y 9.0 CEI = 188
CEI = 281.8 /-----------------Y (3.0) (70.91)
CEI = 191
Differences in CEI values result from rounding the ERPG values when converting between PPM and mgAn3.
27 DO A 029465 CONFIDENTIAL
Calculate Hazard Distances. SI Units (Equation 11A) For ERPG-2 = 9mg/m3
US/Brit Units (Equation 1IB) For ERPG-2 = 3 PPM
hd-655iiHi
AQ HD = 9243
ERPG(MW)
IID = 6551^
HD = 1,878 meters ForERPG-1 = 3 mg/m3
HD = 6551^^?
HD = 3,254 meters For ERPG-3 = 58 mg/m3
98.2 HD = 9243
'3(70.91) HD = 6,280 feet ForERPG-1 = 1 PPM
t 98.2
HD = 9243 11(70.91)
HD = 10,878 feet For ERPG-3 = 20 PPM
VHD = 6551 58 HD = 740 meters
{ 98.2
HD = 9243 120(70.91)
HD = 2,432 feet
Differences in HD values result from rounding the ERPG values when converting between PPM and mgAn3.
&
28 D A 029466
^confidential
AMMONIA UQUID RELEASE
Ammonia is stored in a 12 ft diameter by 72 ft long horizontal vessel under its own vapor pressure at ambient temperature (30 C or 86 F). The largest liquid line out of the vessel is 2 inch diameter (50.8 mm).
Needed information:
Pressure inside vessel, Pg Temperature inside vessel, T Normal boiling point Liquid density in vessel, pi Ratio Cp/Hv Height of liquid in tank, Ah Diameter of hole, D Molecular weight, MW
SI 1064 kPa gauge
30 C -33.4 C 594.5 kg/m3 4.01 E-03 3.66 m 50.8 mm
17.03
US/Brit 154.5 psig
86 F -28 F
37.1 lb/ft3 2.23 E-03
12 ft 2.0 in 17.03
Estimate liquid released.
SI Units (Equation 2A)
US/Brit Units (Equation 2B)
7 , 1000Pe L = 9.44 x 1 O ' D2 pi I--------- + 9.8 Ah
V Pi
L = 2.234 D2 pj ^jS^Ah
L = 9.44 x 10-7(50.8)2(594.5)
1000(1064) + 9.8(3.66)
594.5
L = 61.9kg/sec
L = 2.234 (2.0)2 (37U)i144(154.5) + 12.0
XI 1 L = 8,200 lb/min
Estimate flash fraction. SI Units (Equation 4A)
fv=l(t5-t5)
Hv
Fv =0.0040l(30-(-33.4))
Fv = 0.254
US/Brit Units (Equation 4B) Fv^CTs-Tb)
Hy
FV = 0.00223(86-(-28)) Fv = 0.254
Since Fv> 0.2 AQ = L AQ = 61.9 kg/sec
Since Fv > 0.2 AQ = L AQ = 8,200 lb/min
29 DO A 029467
CONFIDENTIAL
Calculate CEI, SI Units (Equation 10A)
where ERPG-2 = 139 mg/m3 CEI = 655.1 J
y ERPG-2
CEI = 655.1
CEI = 437 Calculate the Hazard Distances. SI Units (Equation 11A) For ERPG-2 = 139mg/m3
HD = 6551 VERPG
HD = 6551
S
HD = 4,372 meters
1
For ERPG-1 = 17mg/m3
i HD = 6551
HD = 12,500 meters ForERPG-3 - 696mg/m3
HD = 655lJ--
V 696
HD = 1,953 meters
USIBrit Units (Equation 10B) where ERPG-2 = 200 PPM
-28ui===
CEI = 281.8 I 82P \ 200(17.03)
CEI =437
USIBrit Units (Equation 11B) For ERPG-2 = 200 PPM
AQ HD = 9243
ERPG(MW) 8200
HD = 9243 200(17.03)
HD = 14,342 feet For ERPG-1 = 25 PPM
h 8200
HD = 9243 ' 25(17.03)
HD = 40,564 feet ForERPG-3 = 1000 PPM
8200 HD = 9243
1000(17.03) HD = 6,414 feet
i-
00 A 029468 CQNFIDENT T AL 30
STYRENE UQUID RELEASE
Styrene is stored in a 40 ft x 40 ft API tank at ambient temperature (25 C or 77 F). The tank has a closed vent system but is essentially at ambient pressure. The outlet is a 6-inch Schedule 40 nozzle.
Needed information:
Pressure inside the tank, Pg Temperature inside the tank, T Normal boiling point Vapor pressure, ambient temperature Liquid density, pi Height of liquid, Ah Molecular weight, MW
SI
0.0 kPa 25 C 145.2 C 0.841 kPa 901.6 kg/m3 12.2 m 104.15
US/Brit 0.0 psig
77 oF
293.4 F 0.122 psi 56.3 lb/ft3
40.0 ft 104.15
Scenario selection -- For greater than 4-inch diameter, use 20% of the cross sectional area (CSA).
For 6-inch Schedule 40, CSA = 28.89 in2
0.20(28.89) = 5.78 in2
D = ^?A = ^5.78 = 2.71 in or 68.9 mm
Estimate liquid released. SI Units (Equation 2A)
7 , [TdooK L = 9.44 x 10-7 D2 p, J--------* + 9.8 Ah
V Pi
L - 9.44 x 10'7 (68.9)2 (901.6)^^^ +9.8 (12.2)
L = 44.2 kg/sec Compare operating temperature to normal boiling point:
25 C< 145 C Therefore, Flash Fraction = 0 Estimate pool size. SI Units (Equation 3A)
WT = 900(h)
WT = 39,800 kg = Wp
US/Brit Units (Equation 2B)
L = 2.234D2 p, JI^L + Ah V Pi
L = 2.234 (2.71)2 (56.3)
+ 40.0
II 56.3
L = 5,842 lb /min
77 F< 293.4 F
US/Brit Units (Equation 3B) WT=15(L) WT =87,6001b = Wp
31
DO A 029469 CONFIDENTIAL
SI Units (Equation 7A) Wp
An = 100--P Pi
Ap =100 39800 p 901.6
Ap = 4,410 m2 Assume no dike. SI Units (Equation 8A)
AQp = 9.0xl0-4(Apa95)^^
Characteristic pool temperature equals ambient AQP=9.0X10^(4410),04;'3<07841> p ' ' 25+273 AQp =0.767 kg/sec
SI Units (Equation 9A) AQ = AQf + AQp AQ = 0 + 0.767 AQ = 0.729 kg/sec
Calculate CEI. SI Units (Equation I0A)
where ERPG-2 = 1065 mg/m3
CE1=65S'i^
CEI = 18
US/Brit Units (Equation 7B) W
A,, = 30.5--EP Pi
, 8760 A =30'5 56.3 Ap =47,460 ft2
US/Brit Units (Equation SB) AQp = 0.154(Ap)<^
AQp =0.,54(474600-)'TM22>
AQp =101 lb /min US/Brit Units (Equation 9B)
AQ = AQf + AQp AQ = 0 + 101 AQ = 1011b/min
US/Brit Units (Equation 10B) where ERPG-2 = 250 PPM CEI - 281.8J(ERpG.2)(MW)
CEI = 28'-8J250(,04.,5)
CEI = 18
32 DO A 029470 CONFIDENTIAL
Calculate the Hazard Distances. SI Units (Equation 11A) For ERPG-2 = 1065 mg/m3
IHD = 6551 AQ ERPG
HD = 6551 I0,767
1065 HD = 176 meters
For ERPG-1 = 213mg/m3
m=65s'JW
HD = 393 meters
For ERPG-3 = 4259mg/m3 HD=65!llM V 4259 HD = 87.9 meters
US/Brit Units (Equation 11B) For ERPG-2 = 250 PPM
HD=9243iS
HD = 9243 I------101 -- \ 250(104.15)
HD = 576 feet For ERPG-1 = 50 PPM
HD = 9243 I 101..-- y50(104.15)
HD = 1,287 feet For ERPG-3 = 1000 PPM
HD = 9243 I----- 1Q1---~ \ 1000(104.15)
HD = 288 feet
DO A 029471 33 CONFIDENTIAL
CHLORINE LIQUID RELEASE
Chlorine is stored in a sphere at 5 C (41 F). A 2-inch nozzle fails on the bottom of the vessel allowing liquid to escape.
Needed information:
Pressure inside the cylinder, Pg Molecular weight, MW Storage temperature, T Liquid density, pi Height of liquid in the sphere. Ah Diameter of hole, D Capacity of sphere
SI 332 kPa gauge
70.91 5 C 1458 kg/m3
6m 50.8 mm 1.134 x 106 kg
US/Brits 48.2 psig
70.91 41 F 91.01 lb/ft2 19.7 ft 2 in 2.5 x 1061b
Estimate liquid released. SI Units (Equation 2A)
L = 9.44x10 7 D7p`illOVOOP^, + 9.8 Ah L = 9.44 x 10-7 (50.8)2 (1458)^^3g32) +9.8 (6)
L = 60.1 kg/sec
USIBrit Units (Equation 2B)
fl44Pg
L = 2.234 D2 p!
- +Ah
V Pi
.OlJ144(48.2)
L = 2.234(2/91
+ 19.7
91.01
L = 7.967 lb/min
Determine the total liquid released.
For 15 minutes (900 seconds), the total liquid leaving the tank is:
Wx = 900(60.1) = 54,090 kg
Wx = 15(7,967) = 119,505 lb
The capacity of the tank when full is 1.134 x 106 kg. Since Lx = 54090 kg is less than the capacity of the tank.
Wx= 54,090 kg
WT = 119,505 lb
Calculate the flash fraction.
Needed information:
Normal boiling point temperature - -34 C
Normal boiling point temperature = -29.2 F
Heat of vaporization = 275,030 J/kg
Heat capacity of liquid (at average temperature) = 943.8 J/kg/C
34 DO A 029472 CONFIDENTIAL.
A technically correct solution for evaluating the flash fraction requires the heat capacity (Cp) to be evaluated at the average temperature (storage and boiling point) and the heat of vaporization at the boiling point. For example:
Cp (@ -15 C or 5 F) = 943.8 J/kg/C = 0.2254 BTU/lb/F
and
Hv (BP) = 285,457 J/kg = 122.72 BTU/lb
SI Units (Equation 4A)
USfBrit Units (Equation 4B)
Fv =0.129
Fv = 0.129
Calculate vapor source strength from the flash.
AQf = 5(FV)(L) = 5(0.129X60.1) = 38.8 kg / sec
(SI)
AQf = 5 (Fv )(L) = 5 (0.129)(7967) = 5,139 lb / min (US/Brit)
Calculate the total liquid entering the pool. Wp = WT (1-5FV) = 54,090(1 - (5)(0.129)) = 19,202 kg
(SI)
Wp = WX(1-5FV) = 119.505(1 - (5) (0.129)) = 42,424 lb
(US/Brits)
Liquid density of chlorine at its boiling point = 1,562 kg/m3
SI Units (Equation 7A)
US/Brit Units (Equation 7B)
A- = lOO--*Pl
WD
Ap = 30.5 --1P Pt
Ap = 1,229 m2
Ap =13,271 ft2
OO A 029473 35 CONFIDENTIAL
Calculate the vapor flow rate from the pool.
Since chlorine is boiling in the pool, Pv = 101.3 kPa = 14.70 psi Molecular weight of chlorine = 70.91
SI Units (Equation 8A)
US/Brit Units (Equation 8B)
AQp = 9.0*10-(Ap"*)(Hm
AQp = 0..54(V'*)TM
AQp = 9.0 xlO"4 (l229095) p ' '(-34.0)+273
AQp =23.3 kg/sec
AAQnp =0n.1i5-4d(1f3i2T71'?^J)7(.02-99120)+44-7509)
AQp =3,083 lb /min
Calculate source strength of release. SI Units (Equation 9A)
AQ = AQf + AQp
US/Brit Units (Equation 9B) AQ = AQf + AQp
AQ = 38.8+ 23.3 AQ = 62.1 kg / sec
AQ = 5139 +3083 AQ = 8,222 lb/min
Compare to the liquid release; 62.1 kg/sec is greater than 60.1 kg/sec and 8,222 lb/min is greater than 7,967 lb/min:
AQ = 60.1 kg/sec
AQ = 7,967 lb/min
Calculate the CEI. SI Units (Equation 10A)
where ERPG-2 = 9mg/m3 CEI = 655.lJ----
\ ERPG-2 CEI = 655.1^--
CEI = 1,963
US/Brit Units (Equation 10B) where ERPG-2 = 3 PPM CEI -281.8^| (ERpa2)(MW)
CEI = 281.8 1 79 -- \ 3(70.91)
CEI = 1,725
This is greater than 1000; thus CEI = 1,000
This is greater than 1000; thus CEI = 1,000
n0 ft 029474 36 CONFIDENTIAL
Calculate the Hazard Distances. SI Units (Equation 11A) For ERPG-2 = 9 mg/m3
HD = 6551 VERPG
HD = 6551 HD = 16,929 meters HD is greater than 10,000 meters, thus HD = 10,000 meters For ERPG-1 = 3 mg/m3 HD = 6551^
HD = 29,321 meters HD is greater than 10,000 meters, thus HD = 10,000 meters For ERPG-3 = 58 mg/m3
HD = 6551 HD = 6,668 meters
US/Brit Units (Equation 11B) For ERPG-2 = 3 PPM
AQ HD = 9243
ERPG(MW) 7967
HD = 9243 ' 3(70.91)
HD = 56,525 feet HD is greater than 32,800 feet, thus HD = 32,800 feet For ERPG-1 = 1 PPM
i 7967
HD = 9243 '1(70.91)
HD = 97,973 feet HD is greater than 32,800 feet, thus HD = 32,800 feet For ERPG-3 = 20 PPM
t 7967
HD = 9243 120(70.91)
HD = 21,907 feet
37 (70 A 029475 CONFIDENTIAL
CHEM ICAL EXPOSURE INDEX FOR SELECTED CHEMICALS FOR RELEASES FROM A 2-INCH DIAMETER HOLE
DO A 0 2 9 4 7 6 CO NFIDENTIAL
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CORPORATE SAFETY, LOSS PREVENTION, AND SECURITY PUBLICATIONS
Minimum Requirements Minimum Requirements for S/LP/S
June 1989
Guidelines Guidelines for A Contractor Safety, Loss Prev., & Security Program, 2nd Edition Guidelines for Safety, Loss Prevention and Security Audits, 3rd Edition Guidelines for Office Safety, Loss Prevention and Security, 2nd Edition Guidelines for Emergency Planning Guidelines for A Motor Vehicle Accident Prevention Program, 3rd Edition Guidelines for Safety on Non-Dow Premises (Reprinted Oct. 1988) Guidelines for S/LP/S Reporting, 5th Edition Guidelines for Root Cause Incident Investigation Fire and Explosion Index Hazard Classification Guide, 6th Edition Guidelines for Public Warehouse Rating & Risk Analysis Distribution Emergency Response Process2 Air Travel - Policy and Guidelines (Reprinted Jan. 1989) Guidelines for Safe Sample Shipping, 3rd Edition Guidelines for A Reactive Chemicals Program, 2nd Edition Guidelines for Handling Dow Proprietary Information, 2nd Edition Guidelines for Personal Safety & Security at Hotels/Motels
and Other Off-Premises Facilities (Reprinted Nov. 1988) Guidelines for Determining Dust Hazard Potential Guidelines For Assessing Potential Acquisitions, 2nd Edition Program Requirements For Hearing Conservation1 Basic Requirements for an Industrial Hygiene Program3 Chemical Exposure Index Guide, 2nd Edition Computer Security Policies, Guidelines and Standards6 Chemical Hazard Engineering Guidelines Environmental Protection Guidelines for Operations Loss Prevention Self-Inspection Guideline Program Requirements for Respiratory Equipment1 Program Requirements and Guidelines for Research and Development
Facilities or Support Laboratories3 Guidelines for Burner Management Systems for Boilers and Process Furnaces Global Hazardous Materials Distribution Guidelines4 Guidelines for Management of Change Program Requirements for Personal Protective Equipment1 Program Guidelines for Ergonomics and Ergonomic Program
Guideline Resource Document1 Guidelines for Chemical Labeling (for the U.S. Area)6 Guidelines for Confined Space Entry
January 1992 November 1989
April 1988 September 1985
May 1992 December 1980
June 1990 February 1993
May 1987 January 1990
1991 April 1980 June 1992 January 1987 March 1991
July 1981 October 1989
July 1992 July 1992 August 1987 September 1993 June 1993
1993 1990 February 1991 October 1990
May 1991 June 1993 March 1991 February 1992 March 1992
September 1992 May 1992 June 1993
Practices Loss Prevention Principles Loss Prevention Principles - Abstracts Operations Practices
Biannually Biannually April 1990
Others Dow Safety Improvement System (DSIS) Dow Safety Improvement System User's Guide Fundamentals of Fire and Explosion - By Daniel R. Stull Topical Index of S&LP Standards & Specifications S&LP Audio/Visual Listing The Office Safety Handbook Security...In The Office & Data Handling Areas
October 1991 April 1992
October 1986 September 1990
1977 1983
Publications Available from: Corporate Safety, Loss Prevention, and Security 2030 Dow Center - Midland, Ml (517) 636-3358 or -6821
10ccupational Health Guide 2US Area Distribution Guide industrial Hygiene Guide
4Corp. Product Dept. Guide Health and Environmental Sciences - CHEC Global Computer Security Resource Center-Freepori
S/93
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