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RMP*Comp Frequent Questions
Quickfinder
- I see that a new version of RMP*Comp is available for download. I have an older version. How do I upgrade it to the new version?
- I've noticed that for certain chemicals, RMP*Comp gives substantially different distances to the toxic endpoint than previous versions. Why?
- I've noticed that for certain chemicals, RMP*Comp gives substantially different distances to the toxic endpoint than I get when I make calculations by hand, following the OCA Guidance procedures. Why the differences?
- I tried running the same scenarios in ALOHA and in RMP*Comp. I got different answers. Why?
- Can I use RMP*Comp for emergency response?
- Will RMP*Comp be updated? If so, would I have to redo calculations I might already have made with an earlier version?
- For alternate release scenarios, RMP*Comp uses set values for meteorological conditions like humidity, wind speed, temperature, stability class, and so on. Is there a way to change those values? I want to use meteorology data from my own location.
- Does RMP*Comp perform some math or modelling in order to arrive at an endpoint distance, or is it simply interpolating from the tables in the EPA's Offsite Consequence Analysis Guidance?
- What kind of software is RMP*Comp?
- Does RMP*Comp have any bugs?
- Is the Windows version a 16-bit or 32-bit application?
- Do we need to obtain either individual or site licenses to use RMP*Comp?
- Can we run RMP*Comp from our server?
I see that a new version of RMP*Comp is available for download. I have an older version. How do I upgrade it to the new version?
Simply download the new installer, then run it (the installer). It will replace older files automatically.
I've noticed that for certain chemicals, RMP*Comp gives substantially different distances to the toxic endpoint than previous versions. Why?
In the current version of RMP*Comp, we have incorporated new chemical-specific distance tables for ammonia, chlorine, and sulfur dioxide. The generic tables are still used for other chemicals (you can see the generic tables in the Offsite Consequence Analysis Guidance (OCA Guidance) (PDF).
I've noticed that for certain chemicals, RMP*Comp gives substantially different distances to the toxic endpoint than I get when I make calculations by hand, following the Off-Site Consequence Analysis (OCA) Guidance procedures. Why the differences?
RMP*Comp was revised in accordance with changes to the OCA Guidance which have not yet been made public. EPA generated chemical-specific distance tables for chlorine, ammonia and sulfur dioxide, and incorporated these tables into the latest, not-yet-public version of the OCA Guidance, which should shortly be made public.
I tried running the same scenarios in ALOHA and in RMP*Comp. I got different answers. Why?
The results you obtain using RMP*Comp may not closely match the results you obtain running the same release scenario in a more sophisticated air dispersion model such as ALOHA or DEGADIS. That's because of a fundamental difference in purpose between those models and RMP*Comp. RMP*Comp is a planning tool, designed to help you to easily identify high-priority hazards at your facility. It makes simple, generalized calculations. In contrast, models like ALOHA and DEGADIS are intended to give you as accurate an estimate as possible of the extent and location of the area that might be placed at risk by a particular chemical release. They account for many more of the factors that influence the dispersion of a hazardous chemical. (For this reason, when you need to make decisions during an actual response, use models like ALOHA or DEGADIS, not RMP*Comp.)
Can I use RMP*Comp for emergency response?
No. It's a planning tool. Many other tools are available for response, including ALOHA and the Chemical Reactivity Worksheet (the Worksheet can be downloaded for free from this site). You can learn more by reading What's in the RMP Toolbox?
Will RMP*Comp be updated? If so, would I have to redo calculations I might already have made with an earlier version?
No, you do not have to redo your work if you have already completed your consequence analyses. RMP*Comp is based on the EPA's Offsite Consequence Analysis Guidance (PDF), which is an "evergreen" rather than a final document; it can be updated as new information or better modeling techniques become available. 1) You are not required to redo your consequence analyses every time there is a change to the Guidance. 2) However, as you develop your analyses, be sure to use either the latest version of RMP*Comp or the latest edition of the Guidance. As changes are made to the Guidance, we'll update RMP*Comp and post a new version here. The current version is RMP*Comp 1.06; it was posted on February 24, 1999. If you have downloaded RMP*Comp, but don't plan to complete your consequence analyses until later, before beginning your analyses, make sure that you have the latest RMP*Comp by comparing the version number on your copy with the version number of the copy on this website.
For alternate release scenarios, RMP*Comp uses set values for meteorological conditions like humidity, wind speed, temperature, stability class, and so on. Is there a way to change those values? I want to use meteorology data from my own location.
RMP*Comp indeed uses fixed values for certain atmospheric parameters, and does not allow them to be set by the user. This is because the software is intended as a simplified model, adhering to the EPA's Offsite Consequence Analysis Guidance (PDF), that is acceptable for compliance with the Risk Management Program (RMP) Rule. Other tools/models may also be used. In order to use local meterological data, you'd have to use one of those other tools.
Does RMP*Comp perform some math or modelling in order to arrive at an endpoint distance, or is it simply interpolating from the tables in the EPA's Offsite Consequence Analysis Guidance (PDF)?
RMP*Comp follows the procedures set out in the OCA Guidance. This means that for some scenarios, the endpoint distance is arrived at via table lookups, for others via calculations. (An example of the latter is the case of pool fires; see Section 12.2 of the Guidance.) However, when table lookups are used, no interpolation is performed (see Section 4.0 of the Guidance).
What kind of software is RMP*Comp?
RMP*Comp ("rmpcomp.sta" and supporting files) is an Oracle Media Objects "stack" (much like a HyperCard stack) that runs on Macintosh computers and in Microsoft Windows 3.1, 95, 98, and NT. To run, it needs the runtime application "OMOPlayer" (on a Macintosh) or "Omoplay.exe" (in Windows) and supporting files, which are all distributed with RMP*Comp.
Does RMP*Comp have any bugs?
Yes. The following bugs appear to be problems with Oracle Media Objects that we cannot fix:
Some Windows users have experienced printing problems. To work around this problem, press the Print button, then click Save to save your work as a text file; you then can print the text file normally. If you wish to report a printing problem, email OEM_Homepage@epa.gov. Please tell us:
- the system being run (i.e., Windows 3.1, 95, 98, or NT). If possible, include the version number (e.g., 4.00.950 B). In Windows 95, this is available from the System control panel.
- the printer and printer driver you're using.
- a detailed description of the problem.
Some Windows users have reported background colors changing to black and white or other color combinations while the program is running. The colors return to normal once you exit the program.
Also, in RMP*Comp versions 1.06 and earlier, for flammable liquid alternative scenario vapor cloud fires, the wrong liquid factors were used. For ambient temperatures, the Liquid Boiling Factor (LFB) was used instead of the LFA. For temps above ambient, the density factor was used instead of the LFB. These errors are conservative (i.e., where the errors significantly effect the outcome of a scenario, they result in an over-estimate of endpoint distance). The errors will be corrected in RMP*Comp version 1.07. Facilities that submit RMP's using OCA results based on RMP*Comp version 1.06 are not required to re-submit their RMPs.
In RMP*Comp versions 1.06 and earlier, the boiling point specified in the OCA guidance (and used in RMP*Comp) for ethylenediamene is incorrect. The boiling point is listed in the OCA guidance as 309.41 K (36 C); the actual boiling point is 390.41 K (117 C).
This error affects the calculation of the Liquid Factor Boiling (LFB) reported in Exhibit B-2 of the OCA guidance. The guidance currently reports ethylenediamene's LFB as 0.13; The corrected LFB is 0.10. This error also affects the Temperature Correction Factors (TCF) reported in Exhibit B-4. Currently, no TCF values are reported for temperatures above 35 C (since a boiling point of 36 C was used). TCF for ethylenediamine should read as follows:
| T (° C) | TCF |
|---|---|
| 30 | 1.3 |
| 35 | 1.8 |
| 40 | 2.3 |
| 45 | 3.0 |
| 50 | 3.8 |
(reported TCFs for 30 and 35 C were correct in OCA guidance) LFA, DF, and LLF are NOT AFFECTED by this error, and are all correct as reported in OCA guidance.
Is the Windows version a 16-bit or 32-bit application?
A. The Oracle Media Objects Player is a 16-bit application (so it runs in Windows 3.1 as well as in Windows 95, 98, and NT).
Do we need to obtain either individual or site licenses to use RMP*Comp?
A. RMP*Comp runs in the Oracle Media Objects Player, a commercial application. Both the Player and RMP*Comp may be freely distributed at no charge.
Can we run RMP*Comp from our server?
The Oracle Media Objects Player was not designed to run over a server, so we recommend that you install RMP*Comp on each user's machine (the Player is automatically installed when you run the RMP*Comp installer).