Industrial Hygiene in Construction

You’ve probably heard of this issue in the news, originally from the CBS News 60-minutes Show, March 1, 2015.

Formaldehyde is NOT good to have indoors, especially with kids (or those with upper respiratory issues). I believe there are a lots of homes and facilities with issues (which are not reported).

There are is some good information out there if you are worried you may have this flooring in your home or business. In summary, here are some notable points:

• you should really ignore the people pushing this issue (remember they shorted the stock before the news story)
• formaldehyde is used in a lot of product during manufacturing
• go to Lumber Liquidators and get your free test kit
• if you find high levels of formaldehyde, do something.
• But, the solution may not be to tear out your floors.
• Remember, formaldehyde can come from many sources.

Here’s a good article on the subject from Galson Labs. If you have concerns, hire a qualified industrial hygienist.

This hazard is somewhat difficult to understand. There are number of reasons for the confusion, but the easiest way to explain it is to realize that:

Summary:

Diesel exhaust = Diesel particulate matter (DPM) = lots of different chemicals & particulates

AND: There is not a perfect way to measure the exact exposure.

The Long Story:

The term ‘diesel particulates‘ includes the following (not a comprehensive list):

• elemental carbon (the most reliable method for testing occupational exposure to exhaust, Birch & Cary 1996)
• organic carbon
• carbon monoxide (CO)
• carbon dioxide (CO2)
• hydrocarbons (PAH)
• formaldehyde
• oxides of sulfur & nitrogen

You can quickly see that these are very different substances, and to make it more confusing, you can change the amounts by:

• the fuel (on road/off, low emission fuel, biodiesel)
• the motor type
• the tuning of the motor (& dynamic versus idle), new motor restrictions
• scrubbers, etc.

In addition, there are not any well-established occupational exposure limits specifically for diesel exhaust. However, the International Agency for Research on Cancer has classified “whole diesel engine exhaust” as a carcinogen (cancer causing), so there is reason for concern. Most of the research and rules are in the mining industry, which uses a lot of diesel equipment and the exhaust really has no where to go.

• OSHA = none, but they have a hazard bulletin, and of course, some of the components have exposure limits
• MSHA = 0.4 mg/m3 for total hydrocarbons and 0.3 mg/m3 for elemental carbon
• Canada (CANMET) for respirable combustible dust (66% of respirable dust in mines is from diesel exhaust) = 1.5 mg/m3
• ACGIH = none (for now)
  • 1995 proposed 0.15 mg/m3 (for diesel particulate matter)
  • 1996 proposed lowering it to 0.05 mg/m3 (for diesel particulate matter)
  • 2001 proposed a different limit of 0.02 mg/m3,
    • but for elemental carbon and
    • said it was a suspected carcinogen
  • 2003 withdrew proposed limit- citing not enough scientific information

Bottom line:

• control the exhaust & where it goes (better fuel, better mechanical, scrubbers, ventilation).
• most exposures to diesel are below the (now retracted) ACGIH TLV of 0.02 mg/m3 (or 20 ug/m3) (Seshagiri & Burton, 2003).
• If you have a confined area, unusual concerns, or a particularly stinky situation; measure for multiple parameters (CO, CO2, elemental carbon and maybe NOx, and SOx). Compare these to their respective limits and classify the exposure (describe the conditions)

Industrial hygiene (aka occupational hygiene) focuses on occupational-related diseases due to many reasons.

Have you considered, at your home, maybe even as you sleep, you might be exposed to something hazardous? Below are seven possible hazards in your home (related to IH):

1. Radon. It comes from the ground and they say it causes cancer* (*some people question this toxicological data). You must perform a test to know if you have hazardous levels.
2. Formaldehyde. If you have a newer house you have 2 things going against you: 1. your house is tightly built (no air leaks and limited fresh air) and 2. more particle board (recycled wood) was used in construction. Also, many furniture contains multidensity fiber wood (MDF) which off gas formaldehyde. Again test for it to know if you have dangerous levels.
3. Lead. Is your house built prior to 1978? It probably has leaded paint. Any remodeling might distrupt it and you can expose your kids to lead.
4. Isocyantes. (HDI, TDI, MDI, and others) Can cause asthma & respiratory issues. If your house was insulated with spray foam (polyurethane type) it needs to off-gas for awhile before you move right in.
5. Asbestos. Causes cancer when airborne. If your house was built prior to 1980, you might have asbestos in your pipe insulation, popcorn ceiling, etc. Be sure and have it checked prior to remodeling.
6. Mold. Respiratory diseases.
7. Cleaning products. The symptoms can vary depending on the type of chemicals in the product. Use the recommended gloves, eye protection and respirator, if necessary, while cleaning with chemicals.

Do not be overly concerned about any one thing. Simply test and make any necessary adjustments. However, do keep in mind that most health recommendations for substances relate to normal working adults who go home to a non-hazardous place. There can be issues if you are either: not considered in the general population of healthy workers and, you go home to a place that isn’t free of additional hazards.

It’s not a secret. (previous article here) Formaldehyde is in many types of composite, pressboard, and multidensity wood products. The EPA is now proposing to limit the amount of formaldehyde that can be added to these types of products.

When you build a structure, these types of products can offgass small amounts of formaldehyde. Even though the total formaldehyde is far less than 1% of the total product by weight/volume (which means it may NOT be listed on the SDS/MSDS- clue: look for the Prop 65 label). This can add up. The EPA is proposing to regulate the amount of formaldehyde a product can off-gas, and provide 3rd party certification framework for regulating it . 

Unfortunately, nowadays “GREEN” products/ or recycled goods can contain a lot of formaldehyde. (used in the process of making & adhering the different recycled materials together).

Expect some push back from industry. Even though it’s a known carcinogen, there is sure to be some push-back.

From what I have seen, there are not a large amount of formaldehyde exposures in construction. However, there is A LOT of formaldehyde used in construction materials. Formaldehyde can be dangerous at levels undetectable by your nose. And, the symptoms of exposure are nondescript (irritant & tingling of eyes, nose, respiratory tract).

Here are some products that may contain trace (or more) amounts of formaldehyde:

• resins in plywood, MDF, CDX, particle board/fiber board
• garage doors
• drywall
• roofing
• glues / mastics
• paint/coatings
• carpets
• insulation (spray in and batting)

I believe the reason we do not see high exposures is due to the limited duration of exposure, and the open-aired nature during the construction. Some exceptions are warehouses with large storage areas of particle board/MDF. (I have found exposures in these areas)

The OSHA exposure limit for formaldehyde is 0.75 ppm (action limit of 0.5 ppm, and short term limit of 2 ppm). However, this may not be low enough, based upon other standards (ACGIH says 0.3 ppm, NIOSH 0.1 ppm)

Another major issue with this hazard in construction is once the space is occupied.

• Once construction is done, the space may be sealed up, heated, and additional curing can occur.
• This may release more formaldehyde, and also NOT allow as much to escape (by dilution ventilation).
• Compounding this issue are the type of occupants in the building. Are there children, non-working adults, immunocompromised individuals, sick, or elderly occupying this space? The OSHA standards are NOT protective for these types of people.

I do not forsee this type of sign being posted immediately after new construction.

On the plus side, someone has discovered that plants may help reduce formaldehyde & VOC levels in homes. Horticulture Science Kwang Jim Kim, et.al