Industrial Hygiene in Construction

There is a lot of confusion over confined spaces in construction. OSHA is enforcing these rules since Aug 3, 2015, but has given a 60 day postponement (effective Oct 2, 2015). Right now you need to make “good faith efforts” to comply. For those in construction, you need to get up to speed, and even more importantly, get confident. Unfortunately, this information isn’t going to get you 100% there.

The reason confined spaces (and the rules) are so complicated is because every space is different. It’s not a minimum height guard rail, or fall arrest system. There are just too many factors, including: 

• the size (or smallness)
• the ventilation (or lack of)
• access (or lack of)
• the work activity (what you introduce)
• the hazards (before you enter, and what you introduce)
• the people inside (people are different, and work different)

To begin getting educated, here are my suggestions:

• Know the definition of (and when it’s) a confined space (hint: 3 things)
• Know the location(s) of your confined spaces (AND mark them as such)
• Train your employees and yourself
• Buy a multi-gas meter
  • And, know how to use it, bump it, and calibrate it
  • And, train others
• Know: host employer, controlling contractor, sub contractor, mobile worker. It may not be obvious.
• Know: ventilation. When you can use it,  what changes, and how much you need
• Understand “rescue”.  And, the answer is not calling 911.

When an accident happens in a confined space, there’s a high likelihood it’s a fatality.

If you have confidence in the rules, and, more importantly, in the hazards & controls, confined spaces can be safe.

Yea, I know. Strange one, huh? In my time consulting, this is actually the second time I’ve come across this.

It is more commonly know as: Mace (R) or tear gas (not pepper spray though, that is Oleoresin Capsicum). Hopefully you haven’t actually experienced it’s exposure. It is worse (so I’m told) than pepper spray. More differences compared here.  All can be quantitatively measured by your favorite occupational hygienist.

Exposure in construction can come from incidental releases (incident response) or during clean up/ demolition of structures where this was used (think: police entry into a structure).

The OSHA exposure limit is 0.3 mg/m3. (NIOSH REL is the same, ACGIH TLV 0.35 mg/m3). They are all very low, actually.  Exposure can occur by inhalation, eyes, ingestion, and skin exposure.  NIOSH Pocket Guide is here.

Personal protection is a bit interesting. NIOSH recommends a full face respirator with P100 and organic vapor cartridges be used. The interesting part is that using this type of protection would allow exposure (based upon the protection factor) up to 15 mg/m3. Which, incidentally, is also the level as immediate danger to life and health (IDLH) = 15 mg/m3.

Some guides for dealing with this substance can be found here.

There are many distinct, separate, and important issues when entering a confined space. The point I would like to make is, as a manager of “safety” , Do you allow your employees to enter a confined space?

Most employers do (with consent, acquiesce ). Below are some questions to consider.

• Do employees know what a confined space is? (see OSHA definition)
• Do they know if it is a permit required space?
• Have they been trained? (this is a separate question)
• Do you control the space? What about the space around it? (what about the space where the air/water comes from?)
• Would you allow any employee to enter?
• Who would you NOT allow? (subcontractors? safety personnel? inspectors?)
• What paperwork/training would you want to see if you did allow these people to enter?

The management of confined spaces is by far the most critical piece. The space could be as innocent as a treehouse, or as dangerous as sewer hole immediately dangerous to life and health.