The researchers studied the flammability of a new, eco-friendly chemical called HFO-1234ze, which is used as a substitute for older, more harmful refrigerants. They collected and analyzed existing data to understand when this chemical can catch fire. New data they gathered show how easily it ignites and the maximum safe gap to avoid flames. The current test methods sometimes underestimate its flammability due to specific conditions and limitations. Overall, with proper safety measures, HFO-1234ze can be used safely by taking into account its true ignition risk.