MSDS
Material Safety Data Sheets
• How toxic is that chemical?
• If a child swallows it, what do I do?
• A Pakistani woman recently drank
household bleach, how much is fatal?
• MSDS sheets provide many answers, our
project for this dry lab experiment
Material Safety Data Sheets
• Required for chemicals used in commerce
– Many listings from suppliers http://sciencelab.com/
• Standard format in 15 parts
–
–
–
–
–
–
–
–
–
NPFA diamond with values for health, fire, reactivity
(1-2) Identification, Composition
(3-4) Hazards identification, First Aid measures
(5) Fire & explosion risk
(6) Accidental release measures
(7-8) Handling and storage, Exposure controls
(9-10) Physical and chemical properties, reactivity
(11) Toxicology, LD50, LC50
(12-15) Ecology, disposal, transport, regulatory.
LD50, LC50
• A measure or index of toxic risk
• The dose when 50% of population dies
• LD50 measurement is exposure by mass
– Ingestion most common, also injection
– Mg of poison per kg of victim, mg/kg
• LC50 is a gas or liquid exposure measure
– Concentration of poison, usually mg/liter
– Exposure could be inhalation, skin contact
Typical MSDS sheet
LD50 usually found in section 11
LD50 details
• Definition for LD50
–
–
–
–
mg/kg = Milligrams of poison per kilogram of victim
Small value is poison, large value is the victim mass
Some materials hazardous in small (mg) amounts
Nicotine 125 mg/kg (rat)
• Why mice?
– Immoral and illegal to use people for experiments
– Nazi war crimes, Dr. Josef Mengele “angel of death”
• See book, Macht Ohne Moral
– Mammals have similar sensitivities to many poisons
– Small animals easy to raise, mature quickly
– Mice, rats, rabbits are common test subjects
Don’t experiment on people!
Josef Mengele pursued as a war criminal for doing that
LD50 definition
A leap of faith
• We ASSUME human equivalency
– Equivalent poison/victim mass ratio
– Not always true, mouse ≠ rabbit data
• Metabolism, tolerances can differ
• Rasputin ate cyanide, shot 3x, then shot 4x
– For Caffeine (section 2, 11) oral LD50
• 192 mg/kg [rat]
• 127 mg/kg [mouse]
• 224 mg/kg [rabbit]
– Which best applies to humans ?
• Consider mammal size, diet/metabolism
• Safest to use smallest numerical value
Application to Humans
Liquor Example
– Ethanol LD50 = 3,450mg/kg (mouse)
– For a 70 kilogram person (154 pounds)
• Poison at 3400 mg/kg, victim weighs 70 kg
• 3,450mg/kg*70kg = 241,500 mg = 241 gm alcohol
• 50% alcohol in whiskey 241/0.5 = 482 gm
– 482gm /0.915 gm/ml = 526 mL (70% of 750 mL bottle)
• 12% alcohol wine  241/0.12= 2,008 gm (≈2 liter)
• 5% alcohol beer 241/0.05=4820 gm (≈5 liters)
– 355 mL per 12 oz, 5 liters = 13.5 cans or 2.3 6-packs
Household Bleach, MSDS
an arranged Pakistan marriage resulted in suicide
• Sodium Hypochlorite
• NaOCl, 5% solution
– Often sold at 6%
•
•
•
•
•
LD50 = 13gm/Kg (rat)
120 lb person ≈ 55kg
13g/kg*55kg = 715g
Density ≈ 1.1g/mL
Volume = 650mL or
about 7/10 quart !
Pakistan village where Shafilea drank bleach to
avoid an arranged marriage
http://www.telegraph.co.uk/news/uknews/crime/9449488/The-Pakistan-village-where-Shafilea-drank-bleach-to-avoid-an-arranged-marriage.html
Common allergy pill
• Acrivastine
• LD50: 2500 mg/kg
(mice, 2 month
expose)
• Dosage 8 mg
• Used in treatment of
allergies and hay fever.
Blocks histamine
receptors in body.
Benadryl and Semprex are trade names
for antihistamine Acrivastine, 8 mg dose
http://www.rxlist.com/semprex-d-drug.htm
What’s an Antihistamine?
Another common allergy remedy
• Cetirizine
• LD50 2,000 mg/kg
(mice, 2 month expose)
• Dosage 20 mg
• Antihistamine
commonly used for
allergies, and hay fever
symptoms
Zyrtec is one of several brand names
for Cetirizine, 10 mg per pill
http://www.rxlist.com/semprex-d-drug.htm http://www.rxlist.com/zyrtec-drug.htm
Common fungal remedies
• Clotrimazole
• LD50 900 mg/kg
(mice, 2 month expose)
• Dosage 10 mg
• Anti fungal medication
used for vaginal yeast
infection, ringworm,
thrush, athlete’s foot.
Mycelex, Lotrimin are brand names for
anti-fungal agent clotrimazole, dose 10mg
http://www.rxlist.com/mycelex-drug.htm
Lamasil Antifungal
• Terbinifine
hydrochloride
• LD50 20,000 mg/kg
• 250 mg dose (oral)
• Antifungal agent,
internal and external
Lamisil anti-fungal
http://www.rxlist.com/lamisil-drug.htm
Common allergy remedies
• Loratadine
• LD50 = 50 mg/kg
(mice, 2 month expose)
• 10 mg/tablet
• Antihistamine for
allergies. Chemically
related to anti-depressant
and anti psychotic drugs.
Claritin is brand name for Loratadine
http://www.rxlist.com/mycelex-drug.htm
How dangerous are these?
• Assume 154 pound (70 kg) person
• How much for 50% risk of death?
Not all people have same sensitivity
Grigori Rasputin, Russian mystic and confidant to the Tsars
•
•
•
•
•
•
•
•
•
“Mad Monk” Rasputin murdered 1916
Given enough Cyanide to kill 5 people
Stabbed with entrails hanging out
Shot and clubbed into submission
Shot 4 more times by assassins
Tied up and wrapped in a carpet
Thrown into icy Niva River
Escaped from carpet and bonds
Autopsy cause of death …. Drowning !
• You could be more sensitive than
others, or maybe like Rasputin. MSDS
values are only a guideline, be careful.
What about herbicides?
Tough on plants, “Roundup” very commonly used, low risk
best to wear gloves, note dermal (skin absorption) risk, “G” = general use
http://pubs.cas.psu.edu/freepubs/pdfs/uo222.pdf (for a long list)
Insecticides
Malathion in aerial spray used to combat fruit-fly infestation
skin absorption more dangerous than ingestion?, “R”=restricted use
Why Malathion?
•
Malathion is a pesticide that is widely used in agriculture, residential
landscaping, public recreation areas, and in public health pest control
programs such as mosquito eradication. In the US, it is the most commonly
used organophosphate insecticide.
•
Malathion was used in the 1980s in California to combat the Mediterranean
Fruit Fly. This was accomplished on a wide scale by the near weekly aerial
spraying of suburban communities for a period of several months.
Formations of three or four agricultural helicopters would overfly suburban
portions of Alameda County, San Bernardino County, San Mateo
County, Santa Clara County, San Joaquin County, Stanislaus County,
and Merced County releasing a mixture of malathion and corn syrup, the
corn syrup being a bait for the fruit flies. Malathion has also been used to
combat the Mediterranean fruit fly in Australia.
•
Malathion was sprayed in many cities to combat West Nile virus. In the Fall
of 1999 and the Spring of 2000, Long Island and the five boroughs of New
York City were sprayed with several pesticides, one of which was malathion.
While it was claimed by some anti-pesticide groups that use of these
pesticides caused a lobster die-off in Long Island Sound, there is as of yet
no conclusive evidence to support this.
B.T. Collins’ Malathion cocktail
a potentially dangerous publicity stunt
http://www.erowid.org/psychoactives/health/psychoactives_ld50s.shtml
LC50
• Lethal Concentration, kills 50% population
– Applies to liquids & gaseous poisons
•
•
•
•
Termite tenting of house
“Bug Bombs”
Insecticides
War gases (Chlorine, “nerve gas”)
– May have skin exposure, inhalation values
– Expressed in concentration units
– Milligrams poison per liter of dilution
LC50 examples
• grams of poison per
liter of gas or liquid
• Insecticides
• Nerve gas
• Cyanide (Zyklon B)
• Carbon Monoxide
• WWI chlorine
Chemical Warfare using Gases
Hazardous Materials, NFPA-704 Diamond
Symbol in white for specifics (radioactive, don’t use water, etc.)
Firemen might NOT enter area with danger value >2
Go to http://sciencelab.com
click on “chemical MSDS” Listing.
A list of chemical MSDS also on Jaguar
Chem 32A MSDS Experiment 2
• Description in Selfe Manual, page 9-14
• Worksheets in Lab Supplement
– Avoid writing in text so you can return it
– Turn in the worksheets & calculations
– Turn in the 2 MSDS you choose from web
– We are interested in sections 9-11 hazards
• Don’t forget cover sheet + your review
– One page over the data sheets