Chemical manufacturing and refining have their own variety of hazards associated with them. I have zero knowledge or detail regarding the specific incident at this chemical complex in Plaquemine. I am though well experienced in the chemical and refining industries, very closely related to each other. Blissfully retired ChE.
The feed stocks and products usually are flammable, corrosive, and/or have health hazards under certain conditions. These are managed via training, maintenance, design and obsessive attention to detail.
There are differences in the safety culture from on company to another. Myself as an example…. My root training and experience was with companies with extremely high end safety cultures and training.
Later in my career and in consulting, I simply needed to pull a sample of liquid from a 500K gallon tank. I made an appointment with operations and an operator and I went out to the tank. The operator's PPE gear was normal Nomex coveralls, hard hat, steel toe boots, heavy dish washing grade gloves and a full face gas mask. By my company's and my own personal standards using MSDS information, I was more robustly dressed out. Rubber steel toe boots, Nomex, hard hat, full chemical slicker suit with hood, heavy chemical grade gloves and gas mask.
In the 80-90 time frame there were several incidents with mass fatalities in chemical and refining and safety incidents industry wide were increasing. The two I have in mind had about 30-40 fatalities each IIRC. Both happened during plant maintenance shutdowns.
Root cause…. Contractor maintenance crews did not speak or understand English. Base safety training was haphazard, daily safety and work task briefings involved folks bobbing their head yes I understand but they started the day not knowing exact conditions. Both of these incidents happened during total maintenance shutdown and were because lockout padlocks on valves and pumps were removed with a bolt cutter. To address this training problem, a regional safety council was established to provide base and specialized safety training for all contractor persons. This was in both English and Spanish. Due to my work as a consultant, I had to going through this regional training in at least half a dozen regions in the US.
I've been on a number of HAZOPS (hazard operations) teams. This is an OSHA requirement for all new and most modified systems before they can be brought online. This is typically a small core of senior operators, a production engineer, a process engineering expert, a manager and a secretary to create the record of the review. In the 90s when the HAZOPS review became mandatory, all existing operations had to reviewed by a certain date as well. It took one refinery I'm familiar with 12 months to work through all their existing units.