Industrial Hygiene in Construction

As a guy, I must admit… these tools are really cool. They’re loud, look like a space-age pistol, and have loaded bullets.  They use a .22 or .27 round casing  to drive the nail through the wood (or steel) stud (or bracket) and into the concrete.  It is really fast and …essentially a gun.

Powder actuated tools (sometimes confused with power, but it’s not) are typically used as  a quick method to anchor into concrete. There are a few types of these tools (Hilti, Simpson, Ramset) and there are specific safety precautions and controls that must be in place during use. However, I will focus on the newer hazard that was brought to my attention:  airborne lead exposure during their use.

I have seen these in use for many years, and at one point it was brought to my attention that lead was listed in the MSDS in section 2 Hazardous Ingredients (lead styphnate) and some of the manufactures caution the extended use of the tool. I actually dismissed the concern for airborne releases.   Well, I was corrected.

A study done by Liberty Mutual’s Mark Wiggins, CIH, CSP, ARM found that when as few as 50 to 90 loads are used per shift, the OSHA Action Limit can be exceeded.  It depends upon the type of load, where work is being done (location), and the type of work (overhead, etc).  He also suggests that the airborne exposure can be estimated based upon the number of rounds.

There are many alternatives to minimizing this exposure including: using battery-operated, or pneumatic anchoring tools, loads without lead, decreasing the frequency of use, and finally- respirators. A half-face, tight fitting negative pressure respirator is suggested to be adequate.

Leave me a comment if you would like the more information about this study.

Some workers were performing MIG (gas metal arc) welding and subarc welding. This is a daily task and their employer requested that we measure the air – as a general assessment tool. In other words, employee’s weren’t concerned, and no one was complaining, but they wanted to explore further into this aspect of their employee’s health and wellness.

We performed air monitoring and analyzed as a welding fume profile which is a number of commonly found welding metals including:

• Antimony
• Beryllium
• Cadmium
• Chromium
• Cobalt
• Copper
• Iron Oxide
• Lead
• Manganese
• Molybdenum
• Nickle
• Vanadium
• Zinc Oxide

Along with the welding fumes, we ran a sample for hexavalent chromium using OSHA Method ID215.

Nowhere in the MSDS (material safety data sheet) did it list “chromium” in the material make-up. However, knowing that it could be a trace metal it might be an issue. MIG welding (in general) isn’t typically of high concern for this hazard. And, as it turns out, the results were found to be below their respective limits.

Employees were not welding the entire day.  At least half of the time was spent fitting, moving, tacking, remeasuring, and gathering materials. Noise was a big issue as well. Most of the day it was quiet, but when the steel would drop, or an “adjustment” to the metal was needed…it was usually followed by a hammer-bang.  Honestly, without the ear plugs, it scared me.

I was requested to perform training for a management team (VPs, Estimators, Superintendents, PMs, PEs) on health topics. The request was specific: asbestos, lead, silica and mold/ IAQ (indoor air quality). I was given an hour, which is hardly enough time. However, the audience took well to it.  I was impressed with the questions and discussion that followed the training. Here are some highlights from that training that the management team adopted as policy. Most of these can be considered tips for good management of IH programs.

ASBESTOS:

• Before the project begins we will have (in writing) an asbestos survey
• As a contractor you typically sub the abatement work
• Employees need awareness training at some level (usually class IV)
• Any asbestos found is to be sampled (by an inspector) and NOT to be touched

LEAD:

• Before the project begins we will have (in writing) a lead survey of the building
• As a contractor we must manage lead on the project (no abatement usually)
• Any lead found on the jobsite WILL BE controlled
• Employees need awareness training – site specific
• Lead ACTIVITY (s)  must be characterized and assessed for possible exposures – and further steps

SILICA:

• There is/will be silica on our jobsite
• We WILL take steps to control the silica exposure when it occurs
• Employees will be trained as to the dangers of silica

MOLD/ IAQ:

• We will manage any mold/fungus found onsite
• We will have a plan for how we handle the situation as we arises
• We will be sensitive to any health or mold/fungus concerns