Maryland hazmat crews are working to contain a sodium hydroxide spill on Snow Hill Road in Girdletree in Worcester County after a tractor-trailer overturned Tuesday. Maryland State Police said in a news release late Tuesday the road is currently closed and will remain so until dawn Wednesday as crews work to tackle the spill. Police said sodium hydroxide is a highly caustic base and alkali that decomposes proteins at ordinary ambient temperatures and may cause severe chemical burns. It is highly soluble in water, and readily absorbs moisture and carbon dioxide from the air. The crash happened at around 4:45 p.m., state police said in a news release. Troopers from the the state police Berlin Barrack responded to 3323 Snow Hill Road in Girdletree for a report of an overturned tractor trailer and hazardous material spill.