# Presentation: 061906

## Experiences in Mercury Spill Clean-up at UCLA

- Presented to
- the American Chemical Society
- April 3, 2001
- Joe Raab, CIH
- University of California, Los Angeles

## The Mercury Haz Mat Story:“When a Good Element Goes Bad”

- Overview of mercury
- Examples of mercury spill clean-ups
- Mercury clean-up tools
- Absorbents and indicators
- Determining “how clean is clean”
- Mercury reduction steps

## Mercury

- Elemental / organic / inorganic compounds.
- Liquid rather than solid at room temperature.
- Low vapor pressure (evaporates slowly) but often produces significant vapor at room temp.
- Mostly absorbed through the lungs or sometimes through damaged and broken skin.
- Usually a lack of acute symptoms, chronic affects to CNS.
- Bio-accumulates in the food chain.

## Items which Contain Mercury

- Gauges, manometers barometers, and vacuum gauges,
- Blood pressure sphygmomanometers
- Mercury switches and relays
- Thermometers

- Mercury containing thermostat probes.
- Dental amalgam
- Hospital equipment
- Laboratory solutions
- Fluorescent & high intensity discharge (HID) lamps

## Types of Mercury Spills at UCLA 1997-1999

## Mercury Incidents at UCLA Center for Health Sciences vs. Campus

## Calculating the Costs (1999 data)

- Disposal cost (assuming 80% due to haz mat events)
- Disposal cost = $34.65/lb.
- 1,437 lbs.
- Total cost = $39,833
- Haz Mat Response Cost
- Labor hours = 280.59
- Personnel cost = $100/hr.
- Total cost = 28, 059

## Office Spill from Mercury Above-Ceiling

- The problem = trapped mercury in plumbing lines above the ceiling
- During demolition of the floor above, approx. 0.25 liters of mercury hit the tiles and contaminated the office below.

## Office Spill from Mercury Above-Ceiling

- Contaminated Materials:
- Ceiling tiles and light fixtures
- Leased office copier
- Carpet
- files
- Etc.
- +  Phase II from trapped mercury in a light fixture  !!!!!

## Pathology Laboratory

- B5 fixative (6.6% mercuric chloride & 2.3% sodium acetate solution)
- Was placed into aluminum container and corroded through onto the floor.

## Pathology Laboratory

- Air and bulk samples revealed extensive contamination of the floor.
- Many attempts made to clean the floor until finally the decision was made to remove it.
- Additional contamination found in sinks and plumbing systems

## Pathology Laboratory

- Floor was ultimately removed and drummed.
- Accomplished using trained abatement workers using jack hammers and controls similar to lead abatement.

## Blood Pressure Sphygmomanometers

- Blood Pressure Sphygmomanometers

- Many recent incidents.
- Contamination of care giver and patient is common.
- Pressure applied results in large dispersal of a large volume of mercury.
- Very difficult clean ups.

## Mercury Thermometers

- Can be well contained or dispersed.
- Drop height increases dispersion.
- Often in ovens, incubators, carts, refrigerators and other difficult areas.
- Haz Mat “Size up” steps are very important.

## Mercury Clean-up Tools

- Vacuum Cleaners
- Mercury spill kits and pumps
- Absorbent sponges
- Direct Reading Instruments
- Personal Protective Equipment

## Vacuum Cleaners

- Advantages:
- Easy pick up of bulk materials.
- Different styles and sizes available.
- Disadvantages:
- May not work on some contamination.
- Need routine maintenance and parts replacement.
- May create vapor during clean-up.
- Expensive

## Mercury Spill Kits and Hand Pumps

- Advantages:
- Good for small spills and individual drops.
- Provide access to difficult areas.
- Disadvantages:
- Not efficient for large spills.
- Requires repetitive action.
- May miss small droplets.
- Eye fatigue.

## Mercury Sponges

- Wetted sponge with amalgam on one side.
- Advantages:
- Best when used with small spills to accumulate and amalgamate small droplets.
- Disadvantages:
- May spread drops around.
- Sometimes does not amalgamate well.
- Can be messy.
- Amalgam can look like Hg.

## Direct Reading Instruments:  Jerome Mercury Monitor

- Direct reading instrument which deposits mercury vapor on gold film and reads concentration based on change in electrical resistance.
- LOD = 0.003 mg/m3.

## Direct Reading Mercury Instruments

_***Advantages:***_
- Accurate real time monitoring of mercury vapor.
- Good for tracking down areas of contamination.
- Aids in the selection of appropriate PPE.
- Aids in identification of contaminated items.

_***Disadvantages:***_
- Direct reading is not directly comparable to PEL.
- Background may be high during clean-up.
- LOD limitations.  May give a false sense of security.
- Can become saturated.

## Personal Protective Equipment (PPE)

- Respirator
- Typically tight fitting half or full face with mercury vapor cartridges.
- End of Service Life Indicator.
- Protective Suit
- Booties
- contamination of shoes is common
- Gloves

## Mercury Absorbents and Indicators

- Typically applied after some effort has been made to take up the bulk material.
- Many require significant application time to absorb the mercury.
- The characteristics of the contaminated surfaces will determine their success.
- Reapplication or additional agitation may be necessary.

## Hg Absorb

- Typically granular zinc and citric acid.
- Acid slightly agitates and frees up the mercury to be absorbed.
- Requires additional clean-up.
- Contact with Hg contamination is important.
- Not good on porous surfaces.

## Mercury Indicator Powder

- Sulfur, Silicon Dioxide, & Proprietary ingredient.
- Sprinkle over spill and wait at least 24 hours.
- Color change from dull yellow to rust.
- Very helpful in identifying problem areas of contamination.

## Liquid Absorbents

- Liquid mixture containing copper sulfate, calcium chloride, potassium iodide, & sodium thiosulfate.
- Apply with sprayer, leave for 24 hours and rinse off.
- Forms mercury sulfide.
- Better on porous surfaces than solid absorbents.

## Determining “How Clean is Clean?”

- Direct reading instrument mercury measurements of non-detect.
- NIOSH Method 6009 using hopcalite tubes and atomic absorption analysis
- Estimated method LOD = 0.3 **g
- What do you compare result to (PEL, 1/10 PEL?)
- Mercury indicator powder - no color change.
- Swipe samples.
- Hazardous waste leachate testing methods.

## Mercury Reduction Steps

- Non-mercury alternatives
- (i.e. Replacement of blood pressure sphygmomanometers)
- Literature campaign
- Substitute chemicals (i.e. zinc chloride fixatives)
- Secondary containment for existing sources
- Future mercury round-ups

## Conclusions

- Mercury spills are disruptive, expensive, time consuming, etc.
- Mercury spills can be very difficult to clean, requiring a variety of tools and well trained haz mat crews.
- Always check personnel in the area of the spill for contamination on their person.

## Conclusions (continued)

- Mercury absorbents and indicators can be essential after the initial clean-up to rid the area of trace material.
- Sometimes a successful clean-up requires the removal of contaminated materials (i.e. carpet).
- Consult waste managers about the disposal of contaminated materials.

## Conclusions (continued)

- Determining the extent of the contamination is difficult and can require a combination of analytical methods.
- Consider long term exposures prior to “clearing” an area.
- The best method for dealing with mercury spills is to prevent them in the first place by using mercury reduction methods.

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