Both. The combustion products of any of the chemicals listed as being on the train so far are CO, CO2, HCl, and trace phosgene. Only VCM has the last two.

Both. The combustion products of any of the chemicals listed as being on the train so far are CO, CO2, HCl, and trace phosgene. Only VCM has the last two. The HCl is the biggest risk because it's the largest product by volume and because when inhaled it forms hydrochloric acid with water in the lungs. Fortunately it will combine with water in the atmosphere if it finds that first.