Dow came to my campus in the Fall semester (October-ish) for a career fair and infosession. I submitted my resume both times, got an on-campus interview. While I didn't immediately get an onsite interview, I was kept in the applicant pool and bounced around to a few sites for interviews and tours before finally getting an offer in February. While I didn't enjoy being dragged around for such a long time, I'm glad that an opening was found for me, as Dow is a great company to work for. Everyone I met was kind and warm and very open, and I never felt that the work environment was hostile or cut-throat in any way.
All interviews I had except one were entirely behavioral, consisting of STAR-type questions meant to address specific attributes in a candidate (i.e. emotional intelligence, problem solving skills, teamwork skills, technical capabilities, etc.) One interviewer asked me three very basic chemical engineering technical questions. I think what they are more concerned about is whether you fit into their culture. As long as you are not awkward and you have some good success stories to tell, you'll be well prepared for the interviews.