I have not blogged for quite a while primarily because in 125 blogs I pretty much exhausted what I wanted to say on various topics. Also, new ideas for blogs from the readers also seemed to have dried up. I am, however, moved to post again by the wonderful work of Daniel Drolet and Tom Armstrong on the tool many of us know as IH Mod. For years, they have wanted to combine the power of these deterministic models with the new dimension of stochastic uncertainty modelling (

*e.g.,*Monte Carlo simulation). Daniel is a brilliant programmer and he made it happen! It is now available as IH Mod 2.0 and, as usual, its a free download. Daniel and Tom and all the folks who worked on this have done so without pay for the benefit of the professional. Below is Tom's announcement. I remain open at mjayjock@gmail.com for ideas for future blogs. I do have another blog that will come out soon with goodies from Jeff Burton and the wonderful tools on ventilation he has recently provided to the profession.

Attention all exposure assessors who use or want to use mathematical modeling to estimate airborne exposure to chemicals! get-involved/VolunteerGroups/Pages/Exposure-Assessment-Strategies-Committee.aspx

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**IH Mod 2.0**and a**Support File**are now available (on the public access Exposure Assessment Strategies Committee web page. https://www.aiha.org/**IH Mod 2.0**includes the same mathematical models as in the still available original IH Mod.**IH Mod 2.0**gives the user the choice between running the models in deterministic (point value parameters) or in Monte Carlo Simulation mode, with choices of distributions of parameter values. This is right in MS Excel with no other software needed. It requires a desktop install of MS Excel, for Windows or Apple computers. The currently posted version has English, French, Serbo-Croation and Japanese language options. Spanish, German and Italian will be available soon.A

**Support File**for IH Mod 2.0 is also available. It includes useful information about IH Mod 2.0, and spreadsheet tabs to estimate liquid spill pool generation rates via the Hummel-Fehrenbacher equation, a units of measure conversion tool, examples of generation rate estimation, a "Bootstrap" procedure tool, a summary of approaches to estimate ALPHA for the exponentially decreasing emission rate models, and some links to other resources. The support file is evolving and will be updated periodically with new information. Check back at the EASC web page (URL above) for updates.