Be-Safe!

							          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.