General Chemical Safety Guidelines (2024)

• Work area:
  • Keep the work area clean and uncluttered.
  • Never play practical jokes or engage in horseplay.
  • Always use adequate safety measures and never leave the following unattended:
    • Ongoing chemical reactions in laboratories
    • Exposedsharps(needles, razor blades, etc.)
    • Energized electrical, mechanical, or heating equipment
• Chemical storage and inventory:
  • Followchemical storageandcompatibilityguidelines.
  • Maintain lean, well managed chemical inventories to avoid fire code violations and subsequent inventory reduction measures.
• Corridors:
  • Keep corridors free of hazardous materials at all times, without exception.
    • SeeCorridor Safety Requirements.
    • Note:There are provisions to allow specific non-hazardous materials to be stored in exit corridors. Such items must be seismically secured and pre-approved by Environment, Health & Safety (EH&S).
    • Contact one of the following for more information:
      • Labs:Research Assistance Program
      • Shop or studio:, (858) 534-7513

• Post:
  • Warning signs near any dangerous equipment, reactions, or conditions
  • A list of chemical abbreviations(PDF) (Word)used on chemical container labels (including hazardous waste) near the lab entrance
  • Personal protective equipment requirements for entering the facility, if applicable
• Labelall containers.
• Keep containers closed except when in use, including hazardous waste containers.

• Evaluate the hazards:
  • Read theSafety Data Sheet(formerly calledMaterialSafety Data Sheets) before beginning work with a chemical.
  • Follow hazard control plans for extremely hazardous materials.
    • Pay particular attention to control measures for chemicals that are known to be particularlyhigh hazardorchemical carcinogens.

• Never underestimate risk.
  • Do not pipette by mouth.
  • Never smell chemicals to identify them.
  • Assume that:
    • Any mixture will be more hazardous than its most toxic component
    • All substances of unknown toxicity are highly toxic

• Be aware of electrical hazards.
  • Keep electrical panels clearly visible and unobstructed.
  • Know how your circuits are labeled so equipment can be de-energized quickly in an emergency.
  • Never use extension cords as permanent wiring. Unplug them at the end of the workday.
  • Mount multi-plug adaptors a few inches off the floor to avoid possible water damage.
  • Never use multi-plug adaptors in series.
  • Replace any damaged or frayed electrical cords immediately.

• Do not eat, drink, store food, smoke, or apply cosmetics in areas where chemicals are in use except in clearly markedClean Areas. Wash your hands frequently and before eating.

• Keep loose hair tied back.

• Usechemical fume hoodsand otherengineering controlsas needed.

Vacuum Trapping

When using a vacuum source, it is important to place a trap between the experimental apparatus and the vacuum source. The vacuum trap

• protects the pump and the piping from the potentially damaging effects of the material
• protects people who must work on the vacuum lines or system, and
• prevents vapors and related odors from being emitted back into the laboratory or system exhaust.

There have been incidents at UC San Diego where improper trapping caused serious failure of building vacuum pumps and in one case in 2009 the explosion was so severe that the pump was completely destroyed leaving the vacuum system in disrepair for months. Luckily no one was injured.

Proper Trapping Techniques
To prevent contamination, all lines leading from experimental apparatus to the vacuum source should be equipped with filtration or other trapping as appropriate.

• Forparticulates, use filtration capable of efficiently trapping the particles in the size range being generated
• For mostaqueous or non-volatile liquids, a filter flask at room temperature is adequate to prevent liquids from getting to the vacuum source.
• Forsolventsand other volatile liquids, use a cold trap of sufficient size and cold enough to condense vapors generated, followed by a filter flask capable of collecting fluid that could be aspirated out of the cold trap.
• Forhighly reactive, corrosive or toxic gases, use a sorbent canister or scrubbing device capable of trapping the gas.

Cold Traps
For most volatile liquids, a cold trap using a slush of dry ice and either isopropanol or ethanol is sufficient (to -78 deg. C). Avoid using acetone. Ethanol and isopropanol
are cheaper and less likely to foam.

Liquid nitrogen may only be used with sealed or evacuated equipment, and then only with extreme caution. If the system is opened while the cooling bath is still in contact
with the trap, oxygen may condense from the atmosphere and react vigorously with any organic material present.

• SeePersonal Protective Equipmentrequirements and resources for research and non-research facilities.

Requirement:To create hazard control plans* (HCPs) for work with high hazard chemicals, use the HCP application.

• See the "High hazard chemicals list" on theHCP page.
• SeeSpecific Chemical Guidelinesfor more information about particularly high hazard chemicals.

* At UC San Diego, a hazard control planisa standard operating procedure (SOP).

Follow basic emergency preparedness best practices:

• Never work alone when hazardous chemicals are involved.
• Prepare for spills.
  • Clean up only very small quantities and only if you have been properly trained. All other spills should be cleaned up by specially trained personnel.
  • ReadHow to Handle Chemical Spills in Laboratories.
  • Keep a fully stockedchemical spill kiteasily accessible.
  • Train personnel on how to use the spill kit, and when it is safe to do so.
• Know the locations of emergency equipment and how to use it:
  • Telephones
  • Emergency Guide
  • First-aid kit
  • Fire extinguishers and fire alarm pull stations
    • ReadFire Extinguisher Types and Maintenanceto learn about different types of extinguishers and how to have them serviced or replaced.
    • Get training: seeFire Extinguisher Trainingfor options.
    • ReadHow to Use a Fire Extinguisher.
    • Check your fire extinguisher monthly to ensure it is charged and accessible.
  • Eye wash and emergency showers

Emergency override buttons (EOBs)

Some laboratories have emergency override buttons (see image at right) installed to provide maximum room ventilation in the event of a chemical emergency that impacts laboratory air.

Activate this button only if you feel laboratory air has been impacted by a chemical emergency.

To activate:

• Open the clear cover and push where it says PUSH HERE. Once activated, room air supply and exhaust will be ramped up to maximum capacity to ventilate the space.
• Evacuate all personnel from the space immediately. Stay out until the room is cleared for reentry.

When the button is pushed, UCSD Police and Environment, Health & Safety (EH&S) will be contacted to investigate. To ensure rapid response:

• Contact UCSD Police after activating the EOB:Call 9-1-1from campus phones.
• Provide the police with any useful information.

When the issue has been resolved, the EOB will be deactivated by authorized personnel and the space will be declared safe for reentry.

First-aid kits and Emergency Guides

First-aid kits(PDF) andEmergency Guidesare provided by EH&S in work areas using hazardous materials or generating hazardous waste.

• The department representative, typically yourArea Safety Coordinator, is responsible for monitoring first aid supplies and expiration dates.
• Contact, (858) 534-3660, if they are missing, damaged, or to request replacement supplies for EH&S-provided first-aid kits.

Read these articles to help you identify and dispose of hazardous waste:

• Identify Hazardous Chemical Waste
• Known Hazardous and Extremely Hazardous Wastes
• Store and Dispose of Hazardous Chemical Waste
• How to Use Hazardous Waste Tags