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Double Insulate Yourself From Danger


By Randy Logsdon

Electrically powered hand tools come in three common varieties:

  • Battery powered.
  • Grounded cord.
  • Double insulated.

The double insulated tool is designed to place an added layer of insulation (a barrier) between the electrical components of the tool and the user. Double-insulated tools are characterized by a two-prong plug and designation on the nameplate with the words “double-insulated” or the symbol of a square within a square.

The more deeply we explore safety applications, the more complex the subject seems to become. Consider the many (bi-directional) institutional relationships with safety. A short list includes planning, training, engineering, hiring, scheduling, discipline, communication and process. Then there is the complexity of compliance – the myriad of safety rules and regulations that we all must understand and properly interpret.

The aim is to provide effective tools and to create an environment that supports safe operations. While operations and safety leadership actively juggle all these concepts and try to make sense of them, the front line worker must condense it all down to one simple goal – to get the job done without injury or damage.

Double Insulate
Create a secure envelope in your work area so that you are protected from injury. That envelope may incorporate several different layers ranging from hazard elimination and various barriers to personal protective equipment (PPE).

In creating this envelope, one should start with a thorough workplace hazard inventory. Identify what can hurt you. Then implement those layers of effective controls. Consider how workers get injured:

  • Falls (slips, trips and falls at the same level or to a lower level. The effects of gravity).
  • Struck by ( line of fire – objects or energy that could be propelled toward you – falling, tipping, flying, rolling, sliding).
  • Stiking (eyes on – striking your elbow against a structure, hitting your thumb with a hammer, crahsing a vehicle).
  • Caught (pinch points, nip points, snagging on a sharp protruding nail).
  • Contact (with electricity, hot/cold objects or fluids, caustics and solvents).
  • Exposure (to weather, noise, dust, gasses, radiaiton, etc.).
  • Overexertion (repetative motion, fatigue, muscle strain, joint sprains).

It’s a fairly simple list – seven inherently logical items to consider for your own safety. The key to success is simply applying a simple two-step process: 1) Identify 2) Control. In my experience, breakdowns in this simple system spring from either an inadequate identification of hazards, failure to apply adequate controls or both.

The Identification of Hazards
The identification of hazards can easily be compromised by expediency (perhaps influenced by a deadline or some other motivation to rush) and by complacency (familiarization with the job or environment). Even if a hazard is recognized, it may be ignored. Hazard identification also has a predictive nature.

New hazards may develop later that are not obvious at the start. This can be influenced by the introduction of work into the system like a cutting torch, process adjustments and the placement of tools, materials, people, and even safeguards. It’s also inherent in the operation of mobile equipment or any movement of the work and worker from one location to another. To borrow from Sir Isaac Newton: What reaction may be anticipated from the actions applied to the work site? Ultimately, the line worker must be not only observant but also intuitive.

Frequently the front line worker has a variety of controls at his/her disposal. Ideally, the sole criteria for selection of the control measure(s) applied would be based on the effectiveness of the control. In fact, based an assessment of the risk by the individual worker, he or she may simply elect to omit additional controls.

Other (less than desirable) criteria for the selection and application of controls frequently relate to convenience – the easiest to obtain, apply or to work around. The worker may simply just use the control that he or she is most familiar with. There may be controls available in the marketplace that are just not avaiable on-site to the individual worker. It pays to keep up with safety technology.

So, the challenge in double insulating the miner is in achieving the consistent and effective application of the most simple of processes – identify and control. And that achievement can be a complex task.


Randy K. Logsdon, CMSP, is manager of safety for Intrepid Potash New Mexico operations. He has practiced safety on both the coal and metal/non-metal side of mining for more than 30 years. Randy is a Certified Mine Safety Professional. ­­­He can be reached at This email address is being protected from spambots. You need JavaScript enabled to view it..