Industrial Hygiene in Construction

I find many construction-related companies who operate a spray booth at their shop. Many are used irregularity, depending on the project. As with most things that are used occasionally, they aren’t always in tip-top shape. Below are a few suggestions and questions for construction firms with these types of equipment.

• Measure the airflow of your booth (there are various ways) but it should be 100 feet per minute. If it isn’t, you need to change something. The filter? the fan size? the exhaust duct size? the make up air (add more)? Please get someone to help you with this. Increasing the motor size is usually the knee-jerk reaction, but NOT usually the solution.
• Make sure your manometer works. Is there a range written on the gauge for “operational”? see arrows at bottom of picture

• Do your employees actually spray inside the booth? (seems like an obvious question but….)
• Are your MSDS nearby?
• Where do the employees mix the paint? (hopefully in a ventilated area)
• Do the employees wear the correct PPE? What about during mixing? When the items are drying?
• Are they covering their necks & arms when spraying? Do they need to? (check the MSDS)
• What product do they clean their spray guns with?
• What product do they thin the paint with?
• Is there a functional eyewash station nearby?
• Do you know the airborne level of exposures to employees?

There is much confusion over the requirements and best practices of employees using respirators voluntarily.

Let me first clarify. You must do air monitoring (or have other verifiable information) that employees are not REQUIRED to wear respirators (if they are overexposed to something, you must protect them). Also, they cannot voluntarily wear a respirators if there is a known hazard above the exposure limit (the employee cannot opt-out of wearing a respirator and be overexposed).

Some points about voluntary use:

• Assuming the above statement (s) is true, firstly, you do not have to allow them to wear respirators. I am sure this is arguable from a human resources/PR/legal stance. However, if you have documented no overexposure and have not provided a respirator, they should not need to wear one.
• Next, the employees need to be educated and you need to prove it. Having them sign Appendix D of the OSHA respiratory rule is a minimum. Training them would be better.
• What respirator are they wearing? A paper dust mask (N95, P100, or similar) is a respirator. If they are wearing anything other than this type of mask they need a medical evaluation (Appendix C of respiratory standard).
• If they are wearing a 1/2 face tight fitting negative pressure respirators (or more protective ones) the company needs to have a written respiratory program.
• Fit testing is not required to be performed
• Maintenance, inspection, storage, and training should always be done. Can you verify that the employee does this?

I personally do not recommend the paper dust masks (N95, or similar) for this simple reason. Why would you wear this type of respirator if you could have a 1/2 face, tight fitting one with the correct cartridge? The cost difference is negligible, the protection is better, and you can be assured of a better fit. If you’re going to do it, do it right.

An agricultural sprinkler and pipe fitting company would not be first on my list for hexavalent chromium exposures. However, they hired a great manager who happens to keep up on safety concerns. He identified the hazard before any work had started.

This company makes custom fittings and pipe for municipals and agricultural systems. The most durable pipes are made of stainless steel. An employee was performing TIG welding for elbows and joints for a new system. In the past I have found that TIG welding produces the least amount of airborne hexavalent chromium (Cr6), so I was not too worried about the airborne levels that might be measured. (keep in mind that there is still a dermal concern, more info here).

However, after interviewing the employee for awhile, he said that plasma cutting and stick welding also occur. Unfortunately air monitoring during TIG welding does not compare with plasma cutting or stick (arc) welding. Additional air monitoring during those activities will have to be performed.

For employees (carpenter, laborer, iron worker, plumber, electrician) using powder actuated tools, please take caution! There are possible airborne lead exposures during powder actuated tool use.

The best safety practice is to eliminate the hazard. In this case there are two easy alternatives;

1. using lead-free loads, or
2. using a pneumatic type nailer (like this one made by Pneutek, Hilti makes a CO2 type as well)

However, if you are an employee, I realize there are times that you are not given a choice. If this is the case, please consider:

• asking for the MSDS for the primer loads (look for lead styphnate, or similar)
• lead exposure can occur by inhalation and by ingestion (wash!)
• wash & be diligent around eating & what you “take home” to your family
• lead exposure to children is serious (they absorb lead better & it causes more detrimental health effects)
• respirators might be required when using these tools (so wear one!)
• working overhead (nailing into ceiling) might have higher airborne levels than other positions
• bringing up these concerns with your safety professional onsite
• performing air monitoring to determine airborne levels (although for the price of an industrial hygiene consultant, you could own a CO2 actuated tool)
• reading more about it from my earlier post here.
  

No, this is not mine. But how funny is this? It is good to be clean!