Failed my first attempt at 67% back in March, which was frustrating since I'd been studying for about 8 weeks beforehand. The exam felt like it covered everything from RCRA to DOT regs to emergency response planning, and I didn't have a solid handle on how it all connected. Took a month off and restructured my approach completely.
Second time around I spent 10 weeks studying, about 90 minutes a day on weekdays and 3 hours on Saturdays. I focused heavily on the HMTRI reference materials and made my own flashcards for the regulatory frameworks. The domain breakdown really matters - Operations and Emergency Response is worth roughly 22% of the exam, so don't underweight it like I did the first time.
What helped most was drilling scenario-based questions instead of memorizing definitions. The exam isn't testing whether you know what hazardous waste is - it's testing whether you can apply 40 CFR Part 262 in a real situation. Scored 79% on the retake and felt way more confident walking out.
The scenario-based approach you're describing is exactly right. I spent too long on pure memorization my first attempt and struggled on anything requiring application of the regs to an actual situation. Retook it six months later and passed at 76%.
79% on a retake is solid. For anyone reading this, the recertification credit requirements are worth understanding before you pass too - makes it easier to build the ongoing study habit rather than scrambling later.
The DOT transport section tripped me up too - I work in environmental compliance but don't handle hazmat shipping day-to-day, so I had to spend probably 15 extra hours on that domain alone. Good to hear the scenario method pays off.
Did you use any specific practice question banks? I'm about 4 weeks out and the IHMM official materials feel thin on practice questions. My weakest area is definitely the liability and insurance coverage sections.
Honestly the thing that finally clicked was when I stopped trying to memorize every regulation in isolation and started thinking about how they actually overlap in a real facility. First time around I had RCRA in one bucket, DOT in another, emergency response in another, and the exam just kept hitting me with scenarios where all three mattered at once. That's where I fell apart. Second time I drilled scenario questions instead of flashcards, and that changed everything. I'd read a question and force myself to ask which regs are in play here, not just what's the definition of this term.
The other big shift was DOT and RCRA waste classification, since that's where I bled the most points. I'd been kind of skimming it before because the tables felt tedious, but you really can't fake it. Slow down on that stuff. I also gave myself more time, closer to 12 weeks with a lighter pace, and that mattered more than I expected because I wasn't burned out walking in. Took it in May and passed comfortably. If you failed your first one don't read too much into it, mine was 67 too and the gap to passing was smaller than it felt.