The Massachusetts Department of Fire Services is reminding residents that a routine stop at the pump can turn dangerous when gasoline is handled carelessly, and the agency is urging people across the Commonwealth to treat fuel as a highly flammable substance, not an everyday convenience. In guidance recently shared on the Massachusetts state website, the Department emphasizes that gasoline vapors can ignite quickly and that even a small spark or a lit cigarette can set off fumes that may cling to clothing.…