Chemical weapons are still being found in Germany decades after the First and Second World Wars. They stem either from the "gas war" between 1915 and 1918, images of which still shock today, or from chemical weapons dating back to the 1940s.

While no chemical weapons were used between 1939 and 1945, both Germany, as well as the allies, possessed huge arsenals of mustard gas, tabun nerve agent and sarin gas.

In Germany, the end of both wars saw tens of thousands of shells and chemical drums simply sunk into the ocean or buried underground.

When drums occasionally wash up on shore or weapons resurface during construction digs, they are sent to a specialized company in Munster. There at the state-owned facility known as GEKA, chemical weapons and huge quantities of conventional munitions have been destroyed in a specialized incinerator.

The premises constitute just a small part of the 167-square-kilometer (65-square-mile) military training area halfway between Hamburg and Hanover. GEKA is owned by the German government and subordinate to the Ministry of Defense.

It is the only facility in Germany allowed to eliminate chemical weapons.

Syria's arsenal

It's perhaps no wonder that the German government has offered GEKA's services for the destruction of Syria's chemical arsenal.

The Organization for the Prohibition of Chemical Weapons (OPCW) has accepted the proposal, and at some point in the second half of 2014, chemical weapons will be delivered to Munster. The materials shipped there will be the treated liquid remnants of 21 tons of Syrian mustard gas. These remnants will be transported from the Mediterranean Sea via ship and rail to northern Germany in 20-foot holding tanks.

The mustard gas will not be neutralized in Munster. GEKA will simply deal with the water run-off resulting from the neutralization process, which will take place in the Mediterranean Sea aboard a US specialty ship's onboard facility. There, the 21 tons of sulfurous agent will, via pressure, hot water and a sodium hydroxide solution, be converted into 370 tons of hydrolysate, a caustic lye solution. Hydrolysate is 72 percent water, 10 percent salt and sodium hydroxide, eight percent thiodiglycol and includes quantities of 1,4-dithiane and 1,4-dioxane.

Like toxic industrial waste

"I'd equate the waste water that comes from the mustard gas' hydrolysate with toxic industrial waste," says Belgian chemical weapons expert Jean Pascal Zanders.

Zanders says the hydrolysate could theoretically be eliminated in conventional incinerators.

But he says it makes sense to ship the fluids on their long journey from southern to northern Europe, and to Germany in particular, precisely because the thiodiglycol component of hydrolysate can be used to manufacture mustard gas - and Germany is considered a safe country.

The expert sees other benefits too: In addition GEKA's experience and industry expertise, its location in Munster is an advantage.

"The area is relatively remote, and the communities that are close to Munster can handle the work going on there."

There have been a number of public protests against the main neutralization work in the Mediterranean, where the mustard gas and a further 540 tons of Syrian chemical agent components are being destroyed on the "Cape Ray" ship.

Steam and salt

It will take about five months for every last drop of the 370 tons of hydrolysate to be vaporized.

The liquid will be injected into a nozzle and sprayed into a special furnace, burning at 1,000 degrees Celsius (1,832 Fahrenheit).

The US military advises that the liquid should be slightly runny. Andreas Krüger, GEKA's technical manager, says this reduces the risk of the nozzles becoming clogged. As a precaution, however, he will begin with small samples in Munster, just to be sure. Other preparations have already been made.

"What we've just had to do was install an additional feed system for the liquid waste, because actually the facility wasn't designed for that. But that wasn't a big technical problem," Krüger says.

And at the end of the process, all that is left of the mustard gas is steam and salt.

The salt is added during the neutralization process.

"With us, these salts are routinely landfilled. They'll be packed into barrels and placed in a long-term landfill."

By that point it will likely be early 2015. And the remnants of once insidious chemical weapons from Syria will be tucked away in underground storage in Sondershausen, a small town in Germany - home to 20,000 people in the state of Thuringia.