Health and Safety in the Laboratory

I. Introduction

Law Protecting Lab Employees

“Occupational Exposures to Hazardous Chemicals in the Laboratory”Requires:

TrainingAppropriate Safety EquipmentMSDS

II. What is a Hazardous Chemical? Determined to be cancer-causing, toxic, corrosive,

an irritant, a strong sensitizer, flammable, or reactive.

Listed under OSHA, 29CFR, part 1910, subpart z. http://www.osha.gov/

Assigned a threshold limit value by American Conference of Governmental Industrial Hygienists (ACGIH)

Routes of Entry

Inhalation a. gases/vapors b. particulates

Eye Contact Skin Contact/Absorption Ingestion

Types of Exposure

Acute Exposure (brief period of time)

Chronic Exposure (months, yrs, decades)

III. Exposure Limits

Several agencies, each with its own set of standards.

Most standards are merely recommendations, only OSHA’s ‘PEL’s have the force of law.

Occupational Safety and Health Administration

Permissible Exposure Limit PEL: Allowable limit for air contaminant, repeated exposure without adverse health effects.

Ceiling C: Exposure limit not to be exceeded at any time during the workday.

Short-Term Exposure Limit STEL: 15 minute time weighted average, not to be exceeded

Time-Weighted Average TWA: Average airborne exposure in any 8-hour shift of a 40-hour work week, not to be exceeded.

Action Level AL: Exposure level at which certain regulations take effect. (analysis, training, medical monitoring, record keeping) Generally ½ the PEL.

Exposure Limits--OSHA

PEL—Permissible Exposure Limit which may be expressed as

A. TWA—Time weighted Average (8 hr)

B. STEL—Short term exposure limit (15 min)

C. C—Ceiling limit

Exposure Limits--ACGIH

American Conference of Governmental Industrial Hygienists

TLV—Threshold limit value (can be exposed repeatedly at this level)

TLV-TWA TLV-STEL TLV-C

Exposure Limits--NIOSH

National Institute of Occupational Safety and Health

REL—Recommended exposure limit (40hr work week)

IDLH—Immediately Dangerous to Life and Health

Toxicity

Toxicity--NIOSH LC50—Lethal Concentration 50 (respiratory)

Kills 50% of test animals after a single exposure in a specific time.

LCLO—Lethal Concentration LowLowest concentration to cause a death in human or

animal. LD50—Lethal Dose 50

Kills 50% by route other than inhalation

Toxicity—NIOSH (cont’d)

LDLO—Lethal Dose Low

TCLO—Toxic Concentration LowLowest concentration in air to show toxic effects.

TDLO—Toxic Dose LowToxic effects evident by route other than inhalation.

IV. Recognizing the Physical and Health Hazards of Chemicals

Hazard Warnings Flammable-acetone, ethanol, benzene Corrosive-ammonia, sodium hydroxide, glacial acetic

acid, mineral acids Compressed gases-Ar, CO2, NH3 anh, N2, LN2

Poison-chloroform, cyanide salts, phenol, methyl isocyanate, mercury(II)chloride, carbon tetrachloride

IV. Recognizing the Physical and Health Hazards of Chemicals…

Explosive - perchlorate salts, barium azide, TNT, picric acid/picrate salts

Pyrophoric – activated carbon, aluminum borohydride, magnesium powder

Water reactive-barium, calcium, lithium, sodium Combustible-phenol, n-propanol, aniline,

benzaldehyde

IV. Recognizing the Physical and Health Hazards of Chemicals…

Carcinogen-Acrylonitrile, asbestos, benzene, carbon tetrachloride, formaldehyde, lead, PCBs, styrene

Infectious Substance-bacteria, viruses, parasites Oxidizer-nitric acid, sodium nitrate, silver nitrate,

hydrogen peroxide Radioactive C-14, Kr-74, P-32, U-230

National Fire Protection Association (NFPA) chemical hazard diamond: http://www.atsdr.cdc.gov/NFPA/nfpa_label.html

Health (Blue) 4 Danger May be fatal on short exposure. Specialized

protective equipment required 3 Warning Corrosive or toxic. Avoid skin contact or

inhalation 2 Warning May be harmful if inhaled or absorbed

1 Caution May be irritating

0 No unusual hazard

Flammability (Red) 4 Danger Flammable gas or extremely flammable liquid

3 Warning Flammable liquid flash point below 100° F

2 Caution Combustible liquid flash point of 100° to 200° F

1 Combustible if heated

0 Not combustible

Reactivity (Yellow) 4 Danger Explosive material at room temperature 3 Danger May be explosive if shocked, heated under

confinement or mixed with water 2 Warning Unstable or may react violently if mixed with

water 1 Caution May react if heated or mixed with water but not

violently 0 Stable Not reactive when mixed with water

Special Notice Key (White)

W Water Reactive Oxy Oxidizing Agent

Flashpoint vs. Firepoint

Flashpoint Lowest temperature at which a flammable liquid gives off sufficient vapor to form an ignitable mixture with air near its surface or within a vessel. Combustion does not continue.

Firepoint The lowest temperature at which a liquid produces sufficient vapor to flash near its surface and continues to burn. Usually 10 to 15 ºC higher than the flashpoint.

V. Material Safety Data Sheets (MSDS)

Specified by OSHA and must contain the following information in 16 sections (but it’s not standard).

1. Chemical Product and Company ID

2. Composition/Information on Ingredients

A. CAS #

B. Relative percents

C. Exposure limits (here or in Section 8)

MSDS (cont’d)

3. Hazards IdentificationA. Description of material and overview of hazards

B. Potential adverse effects including routes of entry and carcinogenic properties.

4. First Aid Measures

MSDS (cont’d)

5. Fire-Fighting MeasuresA. Flash point—lowest temperature at which vapors and air form

an ignitable mixture

B. Auto-ignition temperature

C. Lower Explosive Limit (LEL)

D. Upper Explosive Limit (UEL)

6. Accidental Release Measures—Spill, leak and response procedures

MSDS (Cont’d)

7. Handling and Storage requirements—prevent contact from incompatibles.

8. Exposure Controls/Personal Protection (can be listed in Section 2)

9. Physical and Chemical Properties

10. Stability and Reactivity—provides incompatibilities

MSDS (Cont’d)11. Toxicological Information—usually results of

animal testing

12. Ecological Information—what happens in the environment

13. Disposal Considerations*

14. Transport Information

15. Regulatory Information

16. Other Information

MSDS (Cont’d) *Section 13 - Disposal Considerations

Chemical waste generators must determine whether a discarded chemical is classified as a hazardous waste. US EPA guidelines for the classification determination are listed in 40 CFR Parts 261.3. Additionally, waste generators must consult state and local hazardous waste regulations to ensure complete and accurate classification. RCRA P-Series: None listed. RCRA U-Series: None listed.

potassium permanganate

VI. First Aid

More concerned about (rare) serious incidents rather than the more frequent minor ones (cut finger, minor burn to extremity).

Students/Instructors not required to render first aid but knowing some basics can save a life.

In the event of an accident:

1. Pause to assess the situation. Consider your own safety.

2. Call (or send) for help. Be specific about the nature and the seriousness of the problem.

3. Monitor situation until help arrives.

First Aid Basics a. Acids and bases are corrosive, damaging to tissue.

Treat by flushing with large amounts of water. Eyes must be held open. Do not try to neutralize acid with base, reactions are exothermic.

b. Organic solvents produce sweet smelling vapors. Should always be used in a hood. If you smell vapors and begin to feel lightheaded, close hood and get some fresh air.

First Aid Basics c. Ingestion. Do not induce vomiting.

Corrosive materials can do more damage on the way up than on the way down. Give large amounts of water.

Solvents can be aspirated. If vomiting occurs keep the person’s head below hips and body on its side to minimize aspiration.

d. Fire

Large fire unlikely in Chemistry or Biology lab. Fire in a small container can be put out by smothering..Think ahead, have something available.

Clothing on fire—SDR, fire blanket, safety shower

First Aid Basics d. Fire…(cont)

Even moderately large fires can produce significant amounts of noxious and toxic gases. In such a case, leave it to the professionals.

e. Electrocution

Never touch anyone in contact with live electrical current. Always disconnect power first.

VII. Spill, Leak and Disposal Procedures

1. Be prepared 2. Protect yourself 3. Evacuate the immediate area 4. Identify the spilled material 5. Isolate the spill from related hazards 6. Contain the spill 7. Clean up the spill

Spills, Leaks…….

8. Dispose of the material

9. Clean yourself up

10. Learn from the experience

VIII. Personal Protective Equipment

1. Eye and Face 2. Clothing 3. Gloves 4. Respirators

IX. Laboratory Protocol and Techniques

The Four G’s of Lab Protocol

1. General

2. Glassware

3. “Get rid of” or Dispose

4. Gear

1. General

Drawers/Doors Aisles/Floor Work Surface Cosmetics/Food Smoking Jewelry

2. Glassware

Clean/Defect Free Clutter Disposal Washing Glass Tubing

3. Disposal

Containers Separate Types Drains Reactive Chemicals Ordinary Trash Contractors

4. Gear

Fume Hood Laser UV Sources Compressed Gas Vacuum Dessicator Centrifuge Refrigerator

4….Gear…….

X-Ray Generators/Particle Accelerators Extraction/Distillation Cooling Methods

X .OSHA Regulations

Hazard Communication Standard Laboratory Standard HAZWOPER Standard Blood Borne Pathogens Standard

XI. Environmental Protection Agency

Clean Air Act-1955 Clean Water Act-1972 Resource Conservation and Recovery Act-1976 Comprehensive Environmental Response,

Compensation, and Liability Act-1980 Superfund Amendments and Reauthorization Act-

1986

XII. General Lab Safety Tips 1. Plan ahead. Consider hazards before performing

experiments. 2. Know emergency responses. Locations of

extinguishers, eyewash, shower, spill kit, telephone.

3. Know what you are working with. MSDS. 4. Know and follow safety procedures. Goggles,

protective equipment, special handling, hoods.

…..General Lab Safety Tips…..

5. Report dangerous activities or situations. 6. Store and Handle Hazardous Materials Safely 7. If you don’t know…..ask!