Some chemical emergencies, such as a train derailment or terrorist attack, may make leaving the area of danger (evacuating) dangerous to you. It may be safer for you stay inside where you are.
Overview
All spills are different; this guide cannot give definitive guidance on how to handle every one.
If handled properly, a spill may be nothing more than a nuisance. If handled improperly, a spill can seriously disrupt your activities and the work of your colleagues. At worst, a spill can cause bodily harm or property damage. This substack will help you think logically about your potential spills and plan for a proper response.
Three basic steps should be taken to determine whether a spill is simple or complex: (A) evaluating the spill's risks; (B) evaluating quantities; and (C) evaluating the spill's potential impact.
Evaluate the Risks
The first step in evaluating whether a spill is "simple" is to estimate the risks created by the spill. In spill response, the key risks of concern are human health effects, property damage, and environmental damage.
Human Health Effects
Potential health effects is the most important hazard category to consider when deciding whether or not to attempt a spill cleanup. Some chemical releases may result in health hazards such as fires or explosions. Other chemical releases may present health threats because of their ability to spread rapidly and enter the body readily. A spill is not "simple" if it presents these risks.
If the potential for fire or explosion exists, seek outside assistance from trained emergency responders. Releases of flammable chemicals (liquid or solid) can present significant fire and explosion risks when one or more of the following is present:
volatile vapors,
water reactive or air reactive chemicals,
ignition sources,
oxidizers, and
significant quantities of combustible materials.
Toxic vapors and dust are also hazardous. Avoid direct contact with such hazards because they spread quickly, are easily absorbed through the skin, and may damage tissue.
A chemical spill is not a health risk if it has a low toxicity (especially if it is not volatile or a dust), is not highly corrosive, and is not a strong oxidizer. Such spills may be considered "simple" only if physical damage or environmental factors are absent. When a spilled chemical's toxicity is unknown, treat the spill like a potential human health hazard by avoiding exposure and seeking outside assistance.
General Response Guidelines
For simple spills, emergency responders do not need to be notified. However, you should contact the environmental health and safety office or other responsible person within your facility. Most importantly, before cleaning up a simple spill, be sure that you can do so safely. You must have the right personal protective equipment, including, at a minimum, appropriate eye protection, protective gloves, and a lab coat. Additional protective equipment may be required for spills that present special hazards (such as corrosive or reactive spills or spills that have a splash potential). As a rule of thumb, if you need a respirator, you should request outside assistance because you do not have a simple spill.
The following steps should be taken during spill cleanup.
1. Prevent the spread of dusts and vapors.
If the substance is volatile or can produce airborne dusts, close the laboratory door and increase ventilation (through fume hoods, for example) to prevent the spread of dusts and vapors to other areas.
2. Neutralize acids and bases, if possible.
Spills of most liquid acids or bases, once neutralized, can be mopped up and rinsed down the drain (to the sanitary sewer). However, be careful because the neutralization process is often vigorous, causing splashes and yielding large amounts of heat. Neutralize acids with soda ash or sodium bicarbonate. Bases can be neutralized with citric acid or ascorbic acid. Use pH paper to determine when acid or base spills have been neutralized.
3. Control the spread of the liquid.
Contain the spill. Make a dike around the outside edges of the spill. Use absorbent materials such as vermiculite, cat litter, or spill pillows.
4. Absorb the liquid.
Add absorbents to the spill, working from the spill's outer edges toward the center. Absorbent materials, such as cat litter or vermiculite, are relatively inexpensive and work well, although they are messy. Spill pillows are not as messy as other absorbents, but they are more expensive. Note that special absorbents are required for chemicals such as hydrofluoric and concentrated sulfuric acids.
5. Collect and contain the cleanup residues.
The neutralized spill residue or the absorbent should be scooped, swept, or otherwise placed into a plastic bucket or other container. For dry powders or liquids absorbed to dryness, double bag the residue using plastic bags. Additional packaging may be required before the wastes can be transported from your laboratory. For spills of powders or solid materials, you may need to add a dust suppressant. Be sure to place descriptive labels on each container.
6. Dispose of the wastes.
Keep cleanup materials separate from normal trash. Contact your environmental health and safety officer for guidance in packaging and labeling cleanup residues. Promptly place cleanup wastes in an appropriate hazardous waste receptacle.
7. Decontaminate the area and affected equipment.
Ventilating the spill area may be necessary. Open windows or use a fan unless the area is under negative pressure. In some instances, your environmental health and safety officer can test the air to ensure that hazardous vapors are gone. For most spills, conventional cleaning products, applied with a mop or sponge, will provide adequate decontamination. If you have any question about the suitability of a decontaminating agent, seek expert advice.
Special Precautions
The following precautions apply to chemicals that have hazardous characteristics. Note that some chemicals may exhibit more than one characteristic.
1. Flammable Liquids
Remove all potential sources of ignition. Vapors are what actually burn, and they tend to accumulate near the ground.
Flammable liquids are best removed through the use of spill pillows or pads. Spill pads backed with a vapor barrier are available from most safety supply companies. Because flammable liquids will probably be incinerated, avoid using inert absorbents such as cat litter. All used absorbent materials should be placed in heavy-duty poly bags, which are then sealed, labeled, and disposed through your facility's hazardous waste management program. Before resuming work, make sure the spill area has been adequately ventilated to remove flammable vapors.
2. Volatile Toxic Compounds
Use appropriate absorbent material to control the extent of the spill. Spill pillows or similar absorbent material usually work best because they do not have the dust associated with cat litter, vermiculite, or corn cobs. Place all used absorbent materials in heavy-duty poly bags. Seal the bags, label them, and hand them over to your facility's hazardous waste management program. Again, make sure the spill area has been adequately ventilated before resuming work.
3. Direct Contact Hazards
Carefully select suitable personal protective equipment. Make sure all skin surfaces are covered and that the gloves you use protect against the hazards posed by the spilled chemical. Often it is a good idea to wear two sets of gloves: one as the primary barrier, the second as a thin inner liner in the event the primary barrier fails. When the cleanup is completed, be sure to wash hands and other potentially affected skin surfaces.
4. Mercury Spills
Mercury spills rarely present an imminent hazard unless the spill occurs in an area with extremely poor ventilation. The main exposure route of mercury is via vapor inhalation. Consequently, if metallic mercury is not cleaned up adequately, the tiny droplets remaining in surface cracks and crevices may yield toxic vapors for years.
When a mercury spill occurs, first cordon off the spill area to prevent people from inadvertently tracking the contamination over a much larger area. Generally, a special mercury vacuum cleaner provides the best method of mercury spill cleanup. DO NOT use a regular vacuum cleaner, because you will only disperse toxic vapors into the air and contaminate your vacuum cleaner. If a special mercury vacuum is not available, first use an appropriate suction device to collect the big droplets, then use a special absorbent (available from most laboratory supply vendors) to amalgamate smaller mercury droplets.
Ideally, mercury spills should be prevented in the first place. Examine all uses of mercury to see if substitutes are available. If substitutes are not available, use trays or other equipment to provide spill containment. Spilled mercury often accumulates in sink traps. Be prepared to contain the mercury when servicing such facilities.
Recommended Components of a Chemical Spill Kit
Basic Kit
Kit Container
Accessible
Visible
Securable
Residue Management
Whisk broom or hand-held brush
Plastic dust pan
Metal dust pan
Large, sealable (e.g., ZipLoc) plastic bags
5-gallon plastic drum liners
5-gallon waste disposal container with lid
Absorbants
Paper towels (one roll)
Pillows and brooms
Sheets and pads
Loose bulk (e.g., cat litter)
Mercury Spill Kit (unless it is known that there is no mercury in the laboratory)
Personal Protective Equipment (PPE)
Chemical splash goggles
Face shields
Gloves (proper elastomer for the material in the lab)
Appropriate body protection, such as
Lab coat
Elastomeric aprons
Tyvek suits
Shoe/foot coverings
"Saranex" suits
Basic Emergency Equipment (should be close at hand)
Respirators
Neutralizers (citric acid, sodium bicarbonate, etc.)
Special reactants (chelating agents, etc.)
Decontaminants and biostats (e.g., for blood-borne pathogen cleanup)
Specialized PPE
Decontamination
Decontamination is the process of physically removing or neutralizing contaminants that have accumulated on personnel and equipment; the last step of spill cleanup.
Evaluate the following? Are they contaminated?
All cleanup supplies and equipment (brooms, dustpans, shovels, containers, pipettes, suction tubes, sponges, vacuum cleaners, monitoring equipment, etc.)
Personal protective equipment (chemical suits, respirators, gloves, boots, aprons, etc.)
Any additional equipment in the area may have been contaminated during the spill or release, but may not be obvious. Examples might include analytical and/or computer equipment (particularly for releases of dusts), glassware, bench tops, etc.
Decontamination Processes
The probability and extent of permeation is directly linked to the length of contact. The longer the contact, the more effort that will be required to decontaminate.
Loose contaminants such as dust or vapors may be removed by scrubbing, washing, and rinsing.
Adhering contaminants such as resins and muds may require physical removal by brushing and wiping. The effectiveness of this removal may be improved by solidifying, freezing, adsorpting and adsorpting procedures.
Volatile substances may be removed by evaporation together with washing and rinsing. Be aware of worker exposure during this process!