The on-site manufacture of nitroglycerin was thus required for the remaining hard-rock drilling and blasting required for the completion of the First Transcontinental Railroad in North America.In June 1869, two one-ton wagons loaded with nitroglycerin, then known locally as Powder-Oil, exploded in the road at the North Wales village of Cwm-y-glo. The explosion led to the loss of six lives, many injuries and much damage to the village. Little trace was found of the two horses. The UK Government was so alarmed at the damage caused and what could have happened in a city location (these two tons were part of a larger load coming from Germany via Liverpool) that they soon passed The Nitro-Glycerine Act of 1869. Liquid nitroglycerin was widely banned elsewhere, as well, and these legal restrictions led to Alfred Nobel and his companys developing dynamite in 1867. This was made by mixing nitroglycerin with diatomaceous earth ("Kieselguhr" in German) found in the Krümmel hills. Similar mixtures, such as "dualine" (1867), "lithofracteur" (1869), and "gelignite" (1875), were formed by mixing nitroglycerin with other inert absorbents, and many combinations were tried by other companies in attempts to get around Nobels tightly held patents for dynamite. Dynamite mixtures containing nitrocellulose, which increases the viscosity of the mix, are commonly known as "gelatins". Following the discovery that amyl nitrite helped alleviate chest pain, the physician William Murrell experimented with the use of nitroglycerin to alleviate angina pectoris and to reduce the blood pressure.
Withdrawal symptoms include chest pain and other heart problems. These symptoms may be relieved with re-exposure to nitroglycerin or other suitable organic nitrates.For workers in nitroglycerin (NTG) manufacturing facilities, the effects of withdrawal sometimes include "Sunday heart attacks" in those experiencing regular nitroglycerin exposure in the workplace, leading to the development of tolerance for the venodilating effects. Over the weekend, the workers lose the tolerance, and when they are re-exposed on Monday, the drastic vasodilation produces a fast heart rate, dizziness, and a headache. This is referred to as "Monday disease. "People can be exposed to nitroglycerin in the workplace by breathing it in, skin absorption, swallowing it, or eye contact. The Occupational Safety and Health Administration  has set the legal limit (permissible exposure limit) for nitroglycerin exposure in the workplace as 0.2 ppm (2 mg/m3) skin exposure over an 8-hour workday. The National Institute for Occupational Safety and Health  has set a recommended exposure limit  of 0.1 mg/m3 skin exposure over an 8-hour workday. At levels of 75 mg/m3, nitroglycerin is immediately dangerous to life and health. See also
References
External links
"Nitroglycerine! Terrible Explosion and Loss of Lives in San Francisco". Central Pacific Railroad Photographic History Museum. Retrieved 23 March 2005. – 1866 Newspaper article
WebBook page for C3H5N3O9
CDC - NIOSH Pocket Guide to Chemical Hazards
The Tallini Tales of Destruction Detailed and horrific stories of the historical use of nitroglycerin-filled torpedoes to restart petroleum wells. Dynamite and TNT at The Periodic Table of Videos (University of Nottingham)