So, here's some community service brought to you by The Sensintrovert to differentiate between pepper spray, Mace and tear gas (CS gas), courtesy of Wikipedia. You know, you have to differentiate between apple and orange today, if not, people might be confused...
On pepper spray:
Pepper spray (also known as OC spray (from "Oleoresin Capsicum"), OC gas, or capsicum spray) is a lachrymatory agent (a chemical compound that irritates the eyes to cause tears, pain, and even temporary blindness) that is used in riot control, crowd control and personal self-defense, including defense against dogs. It is a non-lethal agent that can be deadly in rare cases. The American Civil Liberties Union claims to have documented fourteen fatalities from the use of pepper spray. The active ingredient in pepper spray is capsaicin, which is a chemical derived from the fruit of plants in the Capsicum genus, including chillis. Long-term effects of pepper spray have not been effectively researched.
Pepper spray is an inflammatory agent, not an irritant like Mace. It causes immediate closing of the eyes and coughing. The length of the effects depend on the strength of the spray but the average full effect lasts around thirty to forty-five minutes, with mitigated effects lasting for hours.
More info on pepper sprays here.
Mace is a tear gas in the form of an aerosol spray which propels the lachrymatory mixed with a volatile solvent. It is sometimes used as a self-defense device. This form of mace is legal in very few countries, thus its use is becoming uncommon.
The original formulation consisted of 1% CN gas in a solvent of sec-butanol, propylene glycol, cyclohexene, and dipropylene glycol methyl ether. Some formulations now also include Oleoresin Capsicum (active ingredient in pepper spray).
Mace was originally manufactured under the name "Chemical Mace" by Lake Erie Chemical (a former division of Smith & Wesson) in 1962, but is now a registered trademark of Mace Security International. The Mace sold today by Mace Security International is pepper spray rather than tear gas. Many other companies now manufacture similar products.
Due to the current brand-name use of the term "Mace" to refer to pepper sprays and the fact that mace is illegal in most Western countries, it is very difficult to find information on traditional mace. "Mace" and "Pepper Spray" are frequently used interchangeably.
On tear gas (CS gas):
CS Incapacitant Spray is used as a temporary incapacitant, to subdue attackers, or persons who are violently aggressive, by many police forces. The chemical reacts with moisture on the skin and in the eyes causing a burning sensation and the immediate forceful shutting of the eyes. Reported effects can include tears streaming from the eyes, running nose full of mucus, burning in the nose and throat areas, disorientation, dizziness and restricted breathing. In highly concentrated doses it can also induce severe coughing and vomiting.
Although predominantly used by police forces it has also been used in criminal attacks in various countries.
CS is banned from use in war by the 1997 Chemical Weapons Convention (signed 1993), as its use could be a trigger for full scale chemical warfare. However, domestic police use of it is legal in many countries.
So, scientifically correct, which one was used in the attack? You decide...