Ethylene oxide (CAS NO.75-21-8) prepared it by treating 2-chloroethanol with a base. It was first reported in 1859 by the French chemist Charles-Adolphe Wurtz, it achieved industrial importance during World War I as a precursor to both the coolant ethylene glycol and the chemical weapon mustard gas. In 1931, Theodore Lefort, another French chemist, discovered a means to prepare ethylene oxide directly from ethylene and oxygen, using silver as a catalyst. Since 1940, almost all ethylene oxide(75-21-8) produced industrially has been made using this method. Ethylene oxide(75-21-8) sterilization for the preservation of spices was patented in 1938 by the American chemist Lloyd Hall, and it is still used in that role.
 

The Ethylene oxide, with the CAS registry number 75-21-8 and EINECS registry number 200-849-9, has the systematic name of oxirane. And the molecular formula of this chemical is C₂H₄O. It is a kind of colorless gas with a faintly sweet odor, and belongs to the following product categories: Organics; Oxiranes; Simple 3-Membered Ring Compounds; Fumigants Chromatography; General Use; Air Monitoring Standards; Alpha Sort; E; E-LAlphabetic; Insecticides; Volatiles/ Semivolatiles.

The Ethylene oxide, also known as oxirane, is a cyclic ether. It is the simplest epoxide, and because of its special molecular structure, it easily participates in the addition reaction, opening its cycle, and thus easily polymerizes. What's more, it is isomeric with acetaldehyde.
 
The physical properties of Ethylene oxide are as following: (1)# of Rule of 5 Violations: 0; (2)ACD/BCF (pH 5.5): 1; (3)ACD/BCF (pH 7.4): 1; (4)ACD/KOC (pH 5.5): 11.501; (5)ACD/KOC (pH 7.4): 11.501; (6)#H bond acceptors: 1; (7)#H bond donors: 0; (8)#Freely Rotating Bonds: 0; (9)Polar Surface Area: 12.53 Å²; (10)Index of Refraction: 1.404; (11)Molar Refractivity: 10.829 cm³; (12)Molar Volume: 44.283 cm³; (13)Polarizability: 4.293×10^-24cm³; (14)Surface Tension: 31.257 dyne/cm; (15)ensity: 0.995 g/cm³; (16)Enthalpy of Vaporization: 25.54 kJ/mol; (17)Boiling Point: 10.699 °C at 760 mmHg; (18)Vapour Pressure: 1255.443 mmHg at 25°C.

Preparation of Ethylene oxide: It is industrially produced by direct oxidation of ethylene in the presence of silver catalyst. It can also be prepared by treating 2-chloroethanol with potassium hydroxide:
Cl–CH₂CH₂–OH + KOH → (CH₂CH₂)O + KCl + H₂O

Uses of Ethylene oxide: It is one of the most important raw materials used in the large-scale chemical production. It is used for synthesis of ethylene glycols, including diethylene glycol and triethylene glycol. It is also used for the synthesis of ethylene glycol ethers, ethanolamines and ethoxylates. What's more, it is a bactericidal, fungicidal, and sporicidal disinfectant. It is effective against most micro-organisms, including viruses. In addition, it is used as a fumigant for foodstuffs and textiles and as an agent for the gaseous sterilization of heat-labile pharmaceutical and surgical materials. Last but not the least, it is extremely flammable and explosive and is used as a main component of thermobaric weapons.

You should be cautious while dealing with this chemical. It is a highly flammable chemical which irritates eyes, respiratory system and skin. It has danger of very serious irreversible effects through inhalation, in contact with skin and if swallowed. What's more, it may cause cancer and heritable genetic damage. Therefore, you had better take the following instructions: Wear suitable protective clothing and gloves; Avoid contact with skin and eyes; Do not breathe gas/fumes/vapor/spray (appropriate wording to be specified by the manufacturer); Keep away from sources of ignition - No smoking; In case of accident or if you feel unwell, seek medical advice immediately (show label where possible); Avoid exposure - obtain special instruction before use.

You can still convert the following datas into molecular structure:
(1)SMILES: C1CO1
(2)InChI: InChI=1/C2H4O/c1-2-3-1/h1-2H2
(3)InChIKey: IAYPIBMASNFSPL-UHFFFAOYAX

The toxicity data is as follows: