Q&A: Effects Of Tear Gas On Breast Milk?
According to a brochure for Army women by Tammy Anderson, a family nurse practitioner student at the University of Kansas, "The relative half-life [of CS, CN, or OC gas] is very short." Meaning it will pass through your system relatively quickly. She recommends waiting four to eight hours after exposure to breastfeed.
Also, after you're exposed to tear gas, be sure to wash your skin and hair thoroughly with soap and water, and put on clean clothes so you don't transmit the chemical residue to baby.