Perth Petroleum Services Oil & Chemical Spill Equipment

How to clean up a small mercury spill using amalgam powder

Many items used across industry today such as car parts, stabilisers, thermostats and of course, thermometers still contain liquid mercury. We are asked how to handle minor mercury spills on a regular basis.

The following outline is relevant for those who use equipment which contains small volumes of mercury, or for personnel who may be required to clean up a mercury spill.

Properties of mercury

Mercury’s unique properties must be considered. It is important to note and remember the following:

• Mercury will vaporise at normal room temperature. This in turn creates a risk of mercury exposure through inhalation. The risk increases as the temperature increases.
• Mercury is much heavier than water and sinks to the lowest point in any piece of equipment.
• The weight of mercury can cause many standard containers to crack or break.
• Insolubility and the tendency to form small droplets makes mercury spill clean-up and decontamination difficult.
• Drops tend to roll and enter small holes and cracks where they may not be seen. They may become hidden within cracks.
• Its weight, high surface tension and low viscosity can make it very difficult to pour mercury without splashing or spilling.

Equipment

Most small spills of mercury can be cleaned up with the aid of a mercury spill kit however it’s important to note that many off-the-shelf kits only include a gel to help capture mercury droplets.

We recommend using a powder (Mercsorb) to convert the mercury into an amalgam which is then safer and easier to handle.

Safety considerations when dealing with a mercury spill

Remove jewellery

• Firstly, it is important to remove all gold and silver rings, watches and bracelets. If mercury comes into contact with gold or silver, it can bond with the material.

Don PPE

• Wear impervious (PVC) gloves during the spill response.
• If there is a risk of inhaling the mercury vapour, wear a respirator fitted with a Mercury (Hg) filter, especially if the mercury may be warmer than normal room temperature.

Cleaning up the spill

• Mercury easily disperses into fine particles upon impact, becoming much harder to collect. Additional diligence may be required to avoid dropping or scattering through inadvertent contact. Do not allow mercury to be lost in a drain or sewer.
• Never sweep or vacuum mercury with a normal vacuum cleaner. This will disperse the mercury droplets, increase the levels of airborne mercury vapour and contaminate your equipment.
• Do not apply the amalgamation powder onto areas covered by caustic (eg. liquor) or strong acid (eg. acid cleaning. This will dissolve the zinc powder and generate hydrogen gas.

Step by step clean up instructions

1. ISOLATE the area
2. PREVENT people from entering the spill area and spreading the contamination
3. BEGIN the clean-up at the outer perimeter of the spill. Work carefully to avoid spreading the spill and contaminating more areas.
4. ACTIVATE the Mercsorb powder with the wooden spatula by combining two-parts powder to one-part water to create a paste.
5. APPLY a strip of the paste across one end of the mercury contaminated area. Push the strip slowly across the surface with the wooden spatula. Apply the paste in one direction. Small droplets of mercury will be absorbed by the Mercsorb paste.
6. REMOVE the contaminant by gently scraping up the powder into the dust pan. Place contaminated powder into a double-bagged waste disposal bag.
7. SCRUB the contaminated area using a moist sponge and warm water.
8. COLLECT all contaminated waste and equipment used to clean the spill (pan, gloves, etc) in a disposal bag (double bagged).
9. SEAL the contaminated waste bags in the 20L mercury spill kit bucket and label the bucket “Mercury Contaminated Waste”.
10. DISPOSE of the contaminated waste as per your company policy or contact a waste disposal company.

Learn more about mercury response spill kits