Here's the history
Taken from "The Industrial Archaeology of Hertfordshire" by W Branch Johnson and published in 1970.
"At Barwick Ford (Standon) on the river Rib, a few miles north of Ware, are the remains of an explosives factory established in 1889 by the Smokeless Powder Company and designed by the company's engineer, Ernest Spon. The site is about 1,500 ft square, with the Rib on its eastern side and a lane on its western; it is roughly bisected by a wet ditch from the Rib. Much of it today is rough grazing ground; but there remain five stone-built magazines, eleven blast mounds, a factory building now occupied by a firm of specialist motor body builders, the former laboratory, now a private house, and two other houses, one the dwelling of the former works manager.
By 1899 the factory had been taken over by the Schultz Gunpowder Co. a German firm employing nearly all German workers, many of whom were housed on the site. In 1914 they were, of course, interned and the firm transferred to the Government for the manufacture of Sabulite, a high explosive composed of 78 per cent ammonium nitrate, 8 per cent TNT and 14 per cent calcium salicide, used to fill hand grenades and in peacetime for blasting. At the end of the war the factory returned to private hands as the Sabulite Co Ltd, later becoming the Sabulite Snap Co making explosives for crackers - it may be interpolated that a Reliance Snap Co has been similarly engaged at Bishop's Stortford for nearly forty years, though no connection between the two firms has been traced. In 1946, however, the sale of the large estate of which Barwick site formed part led to its purchase by one of the partners in Sabulite Snap Company, Mr H. E. Sears. He closed the works, resold the site in lots and continued to live in one of the houses until his death in 1965."
This was written more than 40 years ago.
I had not realized that so much remains - I may go and have a little look around myself.