Be Safe! Rogers‟ group meeting, June 05 www.drs.uiuc.edu Chemicals and materials we use poisonous corrosives solvents •HF •hexanes, xylenes, toluene •μCP gold etch •SU-8 developer •acetone, alcohols corrosives •strong acids: HNO3, H2SO4, HCl… substrates •strong bases: KOH •semiconductors •halogens (Br, I) •glass •plastic „nano‟s •CNT silicones (PDMS) •μS-Sc •custom (gelest, etc.) •particles •Dow-Sylgard 184 and variants HF “Exposure of less than 10% of the body can be fatal, even with immediate medical treatment. Highly concentrated solutions may lead to acute hypocalcemia, followed by heart attack and death, and may be fatal in as little as 2% body exposure” “Inhalation: Extraordinarily toxic, most likely → CaF2 + H2SO4 250ºC2 HF + CaSO4 fatal in concentrations >200ppm, non-fatal doses can result in pulmonary edema.” •etches SiO2 and many oxides •reacts w/ Ca and Mg in the body Boiling point: 294 K (19.5 ºC) •targets heart, liver, kidneys, nerves, bones •goes through latex gloves—use [thick] nitrile gloves Source: wikipedia.com Corrosives (strong acids, bases, etc.) “they burn you” “they are volatile and burn your lungs” Note: fluorinated silane gives-off HCl Note: μCP Au etch = KOH + cyanide Br and vapors Nanomaterials micro/nanowires asbestos “They get stuck in your lungs and cause trouble.” Examples: •CNT •μS-Sc •metal dust Solvents Hexane, benzene, xylenes, etc.: •make you sick if you get too much exposure. •absorbed through skin •brain damage, reproductive trouble. •keep in fume hood! acetone, alcohols: •make you sick if you get too much exposure. •absorbed through skin •methanol makes you blind and dead— breaks-down like ethanol does in liver, only faster, and produces formic acid and formaldehyde. fatal dose: 4 fl oz. Substrates Hard substrates like glass and wafers break into sharp pieces—big and tiny. Plastic is pretty safe. Silicones Gelest: some of the components are in some harmful solvents. Don‟t inhale them while mixing. Regular 184 seems pretty safe. Just don‟t eat it. Four basics • Know your stuff. When in doubt, ask. • Think and look before you act. (Take your time). • Wear safety gear (glasses, gloves). • Be considerate of others (labels, talk to them). Careful how you mix them Mix ammonium hydroxide and nitric acid, get ammonium nitrate. Ammonium nitrate is a main component of some explosives. Detonations: •Texas City, 1947 •Oklahoma City, 1995 Lesson: store and dispose of acids w/acids, bases w/ bases, oxidizers (incl. HNO3) w/ oxidizers; not with each other.