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.
Honestly I almost didn't bother registering for the second attempt. After that 67% I convinced myself I just wasn't a "regulatory person" and maybe this certification wasn't for me. What changed was that I stopped trying to memorize individual rules and started thinking about how the frameworks talk to each other — like how RCRA waste determinations flow into your emergency response planning, and how that connects back to DOT requirements when you're moving the stuff off-site. Also spent a lot of time on the pollution prevention side, which I'd basically ignored the first time around. The chmm/questions/pollution prevention and sustainability practice questions were actually what helped me see those connections in a way my notes never did.
If you're in that post-fail hole right now, I get it. It's demoralizing. But the test isn't about knowing every CFR citation — it's about understanding why the system is built the way it is. Once that clicked for me the second attempt felt completely different, almost like a different exam. Passed with an 81%.
I failed my first attempt too, so I know exactly how you feel. What changed for me was stopping the random chapter-by-chapter review and actually mapping out how the regulations connect -- like understanding that RCRA governs cradle-to-grave waste management, which then feeds directly into how you think about DOT shipping requirements and emergency response obligations. Once I saw it as one interconnected system instead of separate topics, everything started making more sense.
Also, I'd been way too passive with my studying the first time around. I'd read a section and think I got it, but I wasn't actually testing myself. Second time I forced myself to do practice questions after every major topic, even if I felt like I already knew the material. That's where I found all my gaps. Congrats on passing -- that second attempt feels so much sweeter after a rough first try.
Congrats on passing! Honestly what clicked for me was stopping trying to memorize everything in isolation and instead thinking about how the regulations actually connect to each other. Like once I understood that RCRA waste determinations feed directly into DOT shipping requirements, the whole thing started making more sense as a system instead of a pile of disconnected rules. I also spent a solid week just grinding through practice questions on sustainability topics, specifically stuff like chmm/questions/pollution prevention and sustainability 3, which I'd been skipping because I figured I knew it well enough. I didn't.
The second attempt felt way less overwhelming because I wasn't trying to hold everything in my head at once. Just focus on the connections between the domains and make sure you're not ignoring the areas you think you already know. Those are usually where the points are hiding.
Good timing on this thread. I'm about 5 weeks into my second attempt prep after failing at 71% in June and just hit 78% on a full practice set yesterday, which honestly felt like a turning point. The waste characterization and LDR stuff was killing me before, and I finally feel like it's sticking.
Planning to sit for real in late September if I can keep the scores trending up. Your point about connecting the regulatory frameworks really resonates -- I was treating RCRA and DOT like completely separate buckets and that's where I kept losing points. Good luck to everyone still grinding through it.