The April 15th bombing of the Boston Marathon by what appears to be two Chechen brothers, who were involved in Islamic terrorism, makes us more aware of the need to protect explosives at a mine site. We also need to be aware of chemicals that may be made into an improvised explosive device.

There are several reasons why you must take the threat seriously. First, with increased regulation of explosives, any terrorist groups will find it easier to steal explosives or make them from basic industrial chemicals. Second, as Islamic suicide attacks indicate, these terrorists will go to extreme lengths to get what they want. And casual security will easily be penetrated. Third, militant terrorists will think nothing about killing your employees if they get in the way.

With that in mind, here are some ways you can limit the risk of terrorists from using your mine to plan and execute their next attack.

TRACK AND INVENTORY CHEMICALS AS WELL AS EXPLOSIVES. It appears that the Tsarnaev brothers used old fashioned black powder to make their Boston bomb - proof that a terrorist doesn't need access to commercially manufactured high explosive to kill and maim. This means that terrorists are more willing to use low tech "do-it-yourself" methods to carry out their attacks.

There are a lot of industrial chemicals that may be found at a mine site (or assey laboratory) that a potential terrorist can use to make a bomb. Some of these include nitric acid, sulfuric acid, anhydrous ammonia, and zinc dust. Rather than focus on a few chemicals and what they can do, it would be better to focus on stricter chemical inventory control and limited access storage. This not only limits access to your chemical stocks by terrorists, it cuts down on pilfering.

USE EXPLOSIVES CONTRACTORS. Many mines and quarries hire explosive experts to set charges because it can be cheaper and involves less hassle. It also lowers the threat of losing some of the inventory to terrorists. A contractor who provides services to several mines will be more likely to keep explosives at a central storage facility with greater security. This central storage can have tighter security than several stockpiles of explosives at several mines. And, since there will be more activity at this central location, there will be less likelihood that a theft will go unnoticed for a long period of time.

PAY SPECIAL ATTENTION TO MOVEMENT. Security is more lax during movement of explosives and there are several opportunities to steal it. Movement of explosives means changing the inventory, the truck is a less secure container for explosives, and there is a greater chance that the truck will be left unmanned. The first rule is that trucks that move the explosives must be secured and manned at all times. They can't be left in the field during lunch break, nor should they be left in an unlocked container in the truck with tight custody for the key.

The explosives truck should be tightly controlled. It should leave the secure area just before it's needed and should travel non-stop to the blasting site. After the shots have been set, it should go directly back to the secure area to return any unused explosives.

USE COMPUTER SOFTWARE TO DEVELOP SHOTS. Another weak security area is consumption because unused explosives can be set aside, but be recorded on the inventory as being expended. Modern computer programs, however, have taken much of the guesswork out of explosives consumption. This allows the truck to take the exact amount out to the blasting site instead of a larger quantity.

SECURE DETONATORS. Although detonators are easy to control and inventory, they pose a special problem in this age of terrorism. Many homemade explosives are less sensitive and may fail to explode with an improvised detonator. A commercial detonator makes it more likely that a homemade bomb will work, which makes them special targets for terrorists.

INVENTORY, INSPECT, IDENTIFY. The key to keeping your explosives magazine secure is to inventory the explosives regularly, inspect the stores to make sure the inventories are correct, and to correctly identify anyone allowed access to the explosives. It is important to remember that no one should be allowed to have unsupervised control of the magazine. The person who inspects the explosives stockpile to make sure the inventory is correct and the stocks haven't been tampered with can't be the person who is responsible for the inventory. There must always be a system of checks and balances. That includes a duplicate copy of the inventory kept in the office.

If there are explosives missing, it's important to report it immediately. There is a natural human response to not tell authorities about any missing explosives until a check has been made. However, this is a bad idea in this case. In addition to the bad publicity if your explosives are used in a terrorist attack, the sooner you report it, the greater the chance that the culprits are caught and the explosives returned to safe custody.