CN Rail continues its cleanup of — and investigation into — a train derailment near Fort Frances.

The railway has confirmed some hazardous material spilled when 35 cars went off the rails three weeks ago.

In an e-mail to CBC News, the railway said most of the derailed cars carried potash, while two contained molten sulphur.

Both materials spilled when the cars derailed.

CN said molten sulphur is a dangerous good, but calls the amount of it that leaked "very minor." Potash is not a dangerous good under the Transportation of Dangerous Goods Act.

The railway's environmental and engineering crews remain at the scene to monitor and repair the site. The railway and Transportation Safety Board are still trying to figure out what caused the derailment.

'Best-case scenario'

Fort Frances resident Debra Elias said the incident has her thinking about railway safety.

“If they want to travel with dangerous goods or anything like that down the tracks, I just want to make sure everything is being taken care of,” she said. “The majority of us do live along the tracks.”

Elias said even her workplace overlooks the train tracks.

Fort Frances Fire and Rescue Chief Frank Sheppard said one of the cars containing the molten sulphur had about an 18 inch breach.

He said the spill was considered very minor because “one of the characteristics of the product is — if it does leak out — it cools and, generally, as it did in this case, will form a plug and seals itself. It really was a best-case scenario, and there was very little risk to anyone."

The derailment happened on May 23, at 3:30 p.m. central time.