Can I terminate my month to month tenancy by using ORS 90.460?

The answer depends upon the exact details. Each bedroom is required to have a route of exit and sometimes 2 routes for use in an emergency. The routes must conform to applicable laws in effect during the tenancy so if your city or county has building inspectors, you can ask them to investigate. IF your dwelling does not meet these requirements, you can provide your landlord with a 72 hr notice describing the problem and the date your tenancy will terminate unless it is corrected before then. If the landlord does not fix the problem within said 72 hrs., then you can terminate your tenancy and recover twice your actual damages (such as moving expenses) or 2 months rent, whichever is greater AND the landlord has to return all security deposits and prepaid rent due you by statute within 4 days of the tenancy terminating. So consider reviewing everything in detail with a local landlord-tenant attorney to determine if you have a case and, if so, how to best proceed. Good luck.