Let’s look at recent examples that share a common profile: Disaster preceded by unheeded early warning.

April 5, 2010. Massey Energy Upper Big Branch Mine … 29 fatalities.

In the previous two months, miners had been evacuated three times from the Upper Big Branch because of dangerously high methane levels . In March alone, MSHA cited the Upper Big Branch mine for 53 safety violations. Last year, the number of citations issued against the mine more than doubled, to over 500, from 2008. [New York Times]

April 20, 2010. BP Deepwater Horizon … 11 fatalities and inestimable environmental damage.

Last June, BP engineers expressed concerns that the metal casing the company wanted to use might collapse under high pressure. This March, BP officials informed federal regulators that they were struggling with a loss of well control. This April, BP engineers concluded that the casing was unlikely to be a successful cement job. In April, the month the rig exploded, workers encountered obstructions in the well. [New York Times]

I am neither a coal miner nor an oil driller. But, I worked during the 70s and 80s in chemical plants, which share much in common with mining and drilling. These chemical companies took safety and environmental stewardship seriously. Near-miss accidents were investigated with almost the same intensity as actual accidents. Safety and environmental stewardship were the way business was conducted … a condition of employment!

At the risk of sounding like my father, I ask: Has the current generation of industrial managers and engineers lost its way?! Don’t they realize that hurting workers and the environment is not good business … and is not sustainable!

I suggest that OSHA’s top citations for last year are early warnings …

- Hazard communication (29 CFR 1910.1200). Tell your workers what chemicals they handle and how to protect themselves … this is common sense. Yet, industry is failing to properly provide such basic information!

- Respiratory protection (29 CFR 1910.134). Air contaminates represent one of the most expected workplace hazards. Yet, industry is failing to properly protect its workers! http://www.osha.gov/pls/oshaweb/owadisp.show_document?p_table=STANDARDS&p_id=12716

- Control of hazardous energy – lockout/tagout (29 CFR 1910.147). Electrical and mechanical dangers are appreciated the first time a baby touches a hot stove. Yet, industry is failing to properly implement proven protective measures!

- Powered industrial trucks (29 CFR 1910.178). Properly operating an industrial forktruck is not learned in a high school driving course. Yet, industry is not adequately training its truck operators!

I am saddened when a worker is seriously injured or killed. I am saddened when our environment is destroyed. I am angered when these events are avoidable.

The Massey Energy and BP mishaps – and perhaps OSHA’s citations – suggest that corporate culture that should make safety and environmental stewardship conditions of doing business is losing its way.

Are your safety or environmental programs hearing early warnings? If you need help recognizing and responding to early warnings, please call me.

I can help you develop and implement effective EHS programs. And, if you like, I’ll share my conviction that this is the only way to sustain your business over the long haul.

Do not allow disaster to overtake your business … heed early warnings!

We cannot avoid hurricanes. Leaks happen despite our best efforts. Hurricanes cause power outages for days to weeks. These combined factors cause mold growth in your home … unless specific steps are taken immediately!

First, let’s understand mold. Mold requires moisture to grow. With moisture present, mold takes several days to a week or so to become visible on your walls and furniture. If we eliminate moisture within a week or so, we may minimize or avoid mold damage.

Eliminating post-hurricane moisture – and mold – is described in a four-step process called SERC:

Step 1: Stop Leak (control leak)
Step 2: Extract Water (Mop)
Step 3: Remove Moisture (Dry)
Step 4: Circulate Air (Move air)

Step 1: Stop Source. Under hurricane conditions, usually all bets are off during the storm. However, once the storm passes there is opportunity to cover openings and take other measures to keep water from leaking freely into your home. The point is that unless water leakage is stopped (cover openings) or controlled (catch in buckets), the subsequent SERC steps offer little benefit.

Step 2: Extract Water. Once leaks are stopped or controlled, standing water must be removed (extracted). Mop and bucket are basic tools. A squeegee is useful if there is a doorway through which water can be pushed out of the house. Obviously wet materials (examples: soaked carpet padding, soaked cabinets, soaked drywall) should be promptly carried out of your house and discarded.

Step 3: Remove Moisture. This step involves drying all still-wet and moist materials and surfaces. It is critical that evaporative drying be promoted throughout your home – including within wall spaces and spaces beneath-behind cabinets. Forced air circulation (fans) is necessary. Dehumidifiers promote faster and more thorough drying, if feasible.

Wall openings must be created to allow air circulation through wall spaces. Likewise, bathroom vanities and kitchen counter cabinets must be opened to allow circulation beneath-behind the cabinets. Wall openings can be accomplished by removing baseboards and using a hole saw (at least 2”) to create an opening between each wall stud. Cabinet openings can be accomplished by removing the kick plates.

Step 4: Circulate Air. Once your home is dry, circulate air to remove moisture from nooks and crannies … and minimize humidity buildup. If air conditioning is working, then keep your house closed and use the air conditioning to maintain normal conditions. If air conditioning is not working, open your house (weather permitting) and allow fresh air ventilation.

If applied promptly, SERC can prevent mold from being part of your hurricane aftermath. Water damage is bad enough … mold makes it worse! If your hurricane planning includes SERC, you can be as ready as possible … and minimize or avoid mold damage.

What does a minimum SERC Plan include?

Step 1: Stop Leak … tarp(s), bucket(s)
Step 2: Extract Water … mop, bucket, squeegee
Step 3: Remove Moisture … fan(s), hole saw, generator
Step 4: Circulate Air … fan(s), generator

Plus three preparatory measures …
Contractors. Establish contact with critical contractors at the beginning of hurricane season, not after a damaging hurricane. Critical contractors include roofers, water remediators, repair-reconstruction builders.

Insurance Adjuster. Consult your insurance adjuster regarding storm related damages. Most insurance companies expect the insured to attempt limiting damages following a claim event, such as a storm. Your policy may limit coverage for mold damage. Collecting photographs to document conditions before and during the SERC process is highly recommended.

Mold Assessment & Testing. And, if mold becomes a concern, assessment and testing by a qualified industrial hygienist is critical. This is what ESH does! Call us now to establish early-on contact.

Make sure that SERC is part of your Hurricane Planning!
Call ESH now!

Big Corporations can accept OSHA violations as a cost of doing business. They can afford expensive lawyers, absorb fines with little impact, and shrug off tarnished reputations with PR spin.

Little Companies cannot disregard OSHA violations. They can rarely afford expensive lawyers, endure crippling fines, or suffer lost reputation.

Does your business comply with OSHA regulations? What needs to be done to get into full OSHA Compliance? These questions are answered with an OSHA Baseline Compliance Audit.

An OSHA Baseline Compliance Audit compares your workplace and work practices to OSHA regulations. The Audit is performed by a Health & Safety Professional who is expert on OSHA regulations and their application in workplaces.

An OSHA Baseline Compliance Audit provides a roadmap to achieve and maintain compliance in a manner that fits your business. Action items are prioritized to allow budgeting.

An OSHA Baseline Compliance Audit may be your best investment in this uncertain business climate. A single facility with less than 100 workers costs $1,960. Multiple locations, larger workforces, and distance affect cost.

OSHA Baseline Compliance Audits provide benefit, even if no corrective measures are warranted. Small business owners are adept at juggling risk. Uncertainty is reduced when OSHA Compliance risks are known!

Don’t guess where you stand … avoid expensive lawyers, crippling fines, and loss of reputation!

Allow an ESH Health & Safety Professional to perform an OSHA Baseline Compliance Audit for your business. Call us today!

We offer pre-reclined airline seats … but the seats don’t recline! [Spirit Airlines]

We won triple Safety Awards … with record safety violations! [Massey Energy].

We’re in OSHA Compliance … because OSHA hasn’t performed an inspection in recent memory! [Banks Clark's current impression of small to medium sized companies].

Answer: Headlines don’t tell the rest of the story!

I am bothered by companies that regard the absence of OSHA citations as testimony to an effective Occupational Health & Safety Program. This is like assuming that lightning won’t strike … because you’ve never been struck!

Consider a few recent OSHA citations. Convince yourself that these companies maintained effective OSHA compliance programs … or possibly didn’t take compliance seriously!

[March 2010] Fort Worth, Texas — OSHA cited a company with three alleged willful and 38 serious violations. Proposed penalties total $293,400. The willful citations were:

- Failure to conduct noise monitoring.
- Failure to identify and evaluate respiratory hazards.
- Failure to monitor CO for oil lubricated breathing air compressor.

[March 2010] Delaware City, Delaware. OSHA cited a company for 27 alleged serious violations, including exposing workers to combustible dust hazards. Proposed penalties total $133,500. Additionally, inspectors identified multiple hazards:

- Lack of machine guarding.
- Deficient process safety management program.
- Inadequate lockout/tagout procedures.
- Unguarded machinery, floor holes and walkways.

[March 2010] Willowbrook, Illinois. OSHA cited a company for three alleged serious violations. Proposed penalties total $61,500. Violations included:

- Inoperable emergency lighting.
- Exit signs not illuminated.
- Damaged fall protection lanyard.

The company also received four repeat violations alleging improper personal protective equipment, no hazard assessment certification, no personal protective equipment training certification, and no cover on an electrical box.

Don’t declare OSHA Compliance … just because OSHA hasn’t performed an inspection in recent memory! When OSHA lightning strikes, it is painful and expensive!

Paraphrasing the late Paul Harvey:

Get past the headlines … consider the Rest of the Story!

[My firm provides companies with OSHA compliance audits. We identify workplace hazards and gaps between existing conditions and practices and OSHA standards. These compliance gaps can be prioritized to provide a roadmap for establishing – or re-establishing – compliance. We can help you establish OSHA compliance in a manner that is right for your budget and business. Contact us now! BClark@ESHpartnering.com]

This article suggests that your choice of a Green Home Certification and the Standard that it represents is a crossroad decision. Your choice can affect your Green Home outcome in both the short term and long term.

Described are two different Green Home Certifications for the same house with the same Green Home Features. The two Green Home Standards are LEED for Homes (LEED-Home) and Florida Green Building Coalition (FGBC) Green Home. Both Standards are long established and well respected.

I raise the shades of green question because, in at least in this case, the same house with the same Green Home Features achieved notably different Green Home Certification levels under the two different Green Home Standards. Scoring points and awarded certification levels for this house are summarized in the following table:

Note that the house achieved LEED-Home Silver. The same house with the same Green Home Features achieved FGBC Green Home Platinum.

The LEED-Home Silver Certification represents a more subdued evaluation than the jubilant FGBC Green Home Platinum Certification. Platinum is the top recognition inferring that the house is as-good-as-it-gets. Silver infers that Green Home Features must be strengthened before gaining similar top recognition.

Is this difference significant in real terms? By real terms, I mean how the Green Home will perform against real-world tests such as storms, droughts, and energy shortages?

Let’s look more closely at different treatment of Energy, which is a Green Home core element. The graphic below illustrates the differences.

LEED-Home offers a performance Energy pathway, which is usually chosen in South Florida. In this case, points are granted for HERS Indices below 85. As a prerequisite, house performance must be equivalent to an Energy Star qualified house (HERS Index =85), which is also equivalent to the Florida Energy Code. [Note that the lower HERS Index the better the energy performance.]

FGBC Green Home grants points for HERS Indices below 90. There is no prerequisite.

Whether a LEED-Home or a FGBC Green Home will fare better than the other under a real-world scenario of energy shortages is anyone’s guess. However, it is reasonable to assert that a more energy efficient house will fare better than a less energy efficient house when confronted with energy shortage. It’s sort of like the Three Little Piggies… a brick house will probably fare better than a straw house when confronted with a wind storm.

My purpose here is to raise awareness that different Green Home Certifications may provide different levels of recognition for the same Green Home Features. Platinum under one Green Home Standard may not be materially different than Silver under another Green Home Standard.

A nagging thought is that some Green Home Standards may be more substantive than other Standards. Will houses built against less substantive Standards muster against real-world tests as well as houses built against more substantive Standards?

How will you choose the Green Home Standard for your new home? Will your choice be based upon the short term … most recognition for the dollar? Or, will your choice be based up the long term … real-world performance versus cost and other considerations?

Be aware: Different Green Home Certifications represent … different shades of Green!

Feel free to email or call me to chat. I’d love to discuss your Green Home.

My first connotation of sustainability is Global Stewardship … preserving our Planet Earth. I think of excessive consumption, Climate Change, mindless development … and hugging trees.

Upon reflection, my thinking clears up. Sustainability is really about my family, my kids’ families, my grandkids’ families … and their families to come. It’s personal!

Green Homes (example: LEED for Homes, NAHA Green Home, Florida Green Home) strike a balance between making sure that we have a livable Planet and a livable Home … today and tomorrow!

I submit that a Green Home is all about a healthy living environment … the environment in which my family and your family live. Again, it’s personal! Energy and water efficiency, storm durability, environmentally friendly materials, and location are all elements of achieving and sustaining a healthy living environment.

Understanding Green Building standards is daunting. Standards are similar, yet different. Why choose one standard over another?

Objectively evaluating Green Home alternatives is complex. Am I trying to save money? Ensure good indoor air quality? Or, do I simply wish to do the “right thing”? Or, am I simply trying to impress others?

As you ponder your Green Home Journey, keep it simple. It’s all about you! It’s about your living environment … now and into the future. It has more to do with personal value than personal worth.

Consider your Green Home Journey from within a bubble … your personal living environment. View your Green Home choices from two perspectives: first today … and then as far into the future as you can imagine. Then ask the question: Are my choices improving the wellbeing and healthfulness of my family’s living environment and that of their families to come?

I believe that you will agree: A Green Home Journey is worth pursing …and, it’s personal!

Give me a call. Allow me to be travel agent for your Green Home Journey!

OSHA is proposing to modify Log 300. The modification proposes specific reporting of musculoskeletal disorder (MSD; aka ergonomic) injuries. This proposal virtually restates requirements proposed in 2001. Let’s revisit 2001 … déjà vu Ergonomics Standard!

On January 16, 2001, an OSHA Ergonomics Standard was finalized (President Clinton). On March 20, this Ergonomics Standard was rescinded (President Bush).

At the time our politicians were finalizing-rescinding the OSHA Ergonomics Standard, ergonomic injuries (MSDs) accounted for one-third of all reported occupational injuries and illnesses. These disorders constituted the largest job-related injury and illness problem in the United States. In 1997, employers reported a total of 626,000 lost workday MSDs. These disorders accounted for $1 of every $3 spent for workers’ compensation in that year.

Once the Ergonomics Standard was rescinded, the requirement for specific reporting of ergonomic injuries was withdrawn. Have ergonomic (MSD) injuries been reduced in the following years? If the politicians don’t see an ergonomics problem, employers should see an ergonomics problem … workers are surely suffering ergonomic injuries!

Given no reporting data, we do not really know the actual injury rate related to ergonomic injury. Given the lack of an Ergonomics Standard and enfeebled OSHA enforcement armed only with the General Duty Clause, it is unlikely that MSD injury rate has reduced over the past ten years.

What is the significance of MSD data collection? Reporting specific injury types reveals the extent and severity of the specific injury. If MSD injuries dominate the injury picture today as they did ten years ago, there will probably be increased interest in reviving an OSHA Ergonomics Standard. Don’t worry … OSHA standards making does not move quickly.

Hearing loss injuries have been specifically reported for the past ten years, and, employers have surely reported hearing loss injuries. Yet, the OSHA Hearing Conservation Standard is approaching three decades without substantive change; even though the standard is recognized as fundamentally un-protective compared to almost any other noise standard on the Planet.

What does this mean … other than filling out another column on the OSHA Log 300? I suggest that this is an opportunity for employers to better understand workplace injuries.

OSHA may or may not require reporting of specific injuries. A worker may or may not report an injury that should be known by his employer. Yet, a business person has a vested interest in worker health and safety. Isn’t worker reliability critical to business success?

My message is twofold. First, expect future OSHA’s Log 300 reporting to include specific reporting of ergonomic injuries (musculoskeletal disorders). Second, regardless of OSHA reporting requirements, a clear understanding of ergonomic injury – and other workplace injuries – is good business!

For more information, view OSHA’s proposal. This notice was published in the Jan. 29 edition of the Federal Register.

Indoor air quality is complicated. In some cases, it is best described as a perception, which is annoying to some and perhaps pleasing to others. In other cases, it relates to serious health effects for some, but does not affect others.

An earlier article regarding indoor air quality discussed odors. This article discusses another aspect of indoor air quality: allergens.

Chemicals can also cause health effects. These chemical-caused health effects can be quite different from the health effects caused by allergens. A future article will discuss yet another aspect of indoor air quality: chemicals.

[Please note that I do not pretend to understand fully the distinctions between allergy and asthma, let alone the various mechanisms that cause various allergic responses. However, allergens are too important for us not to attempt to understand and control thier sources within our homes.]

Allergens cause some persons to have allergic reactions, while others are completely unaffected. Most individuals who have severe allergies – especially asthmatics – know their condition and the allergen sources that trigger reaction.

Allergies and asthma are similar in that both are triggered by allergens. Asthma causes inflammation and swelling in the lower respiratory passages (bronchial tubes), which narrows the airways and causes breathing difficulty.

About eleven in one hundred people suffer from some form of allergy. Three of these sufferers are asthmatic.

Allergic reactions can affect nasal membranes, eyes, skin, tongue, and breathing passages in severe cases. Allergy symptoms include an itchy, stuffy, or runny nose, sneezing, itchy, red, or irritated skin, and itchy, burning, or watery eyes.

Allergens can include almost any air pollutant. Most allergens are very small particles, although some are gases. Examples of particles are mold (dead or alive), pollen, pet dander (dogs, cats, birds, reptiles), insect and pest droppings (dust mites, cockroaches, rodents, lizards), food, and smoke. Examples of gases are chemical vapors, including fragrances, combustion soot, cleaning solvents, adhesives, and paint products.

Common Sources

Household Dust. Household dust is a term that describes the ubiquitous debris that accumulates on surfaces and floors within our homes. Since we have cats and dogs, our house dust usually resembles a fur ball; which my kids call dust muffins. Whatever house dust looks like, it is potentially a bouillabaisse of allergens that enter into, or are created within, your home.

Mold. Mold is often blamed for allergic reactions. The Center of Disease Control studied building environments with known indoor air quality complaints. Correlation was found between damp buildings, mold, and complaints (Facts about Mold and Dampness). Further, the media has engrained the notion that Toxic Black Mold is surely the root of all indoor environment evil.

My experience is that many people asking for help for their sick homes firmly believe that mold is causing their discomfort. Their first words are “Test my house for mold!” Mold testing can be expensive ($600 to $2000). I do not recommend mold testing unless there is a known or suspected moisture source or there is a musty odor.

If mold is visible, testing has limited value other than to indicate whether airborne contamination is spread. Testing is more useful after mold-damaged material is removed (remediation). Post-remediation testing verifies that air quality is normal.

Dust Mites. Dust mites are the most common cause of allergy from house dust (House Dust Allergy). They prefer temperatures at or above 70 degrees Fahrenheit with a relative humidity of 75 percent to 80 percent … such as in South Florida.


The good news is that dust mites are easily recognized under a microscope. They look like sci-fi monsters. Carpet and bedding samples are easily collected and viewed under a microscope (400x). Filter samples can be laboratory tested (Allergen-ELISA screen) to confirm the presence of dust mite allergens, as well as allergens associated with pets and cockroaches.

Control
Controlling allergen exposure in our homes relies largely upon eliminating or mitigating prospective sources. For example: tile or wood flooring is better than carpeting; no pets is better than pets; no candles or fragrances is better than ad hoc aroma therapy; humidity control is essential.

Particles. As mentioned earlier, many – if not most – allergens are very small particles (less than 100 microns. HEPA filters (MERV 16) remove 99.97% of particles as small as 0.3 microns. Most mold spores are larger than 1 micron. Most pollen grains are larger than 20 microns. HEPA filters can remove airborne mold spores and pollen grains from your home.

Installing a HEPA or near-HEPA filter in your air handler provides whole removal of allergen particles. Further, equipping your vacuum cleaner with a HEPA filter further removes allergen particles. Vacuum cleaners with standard filters actually disperse, rather than remove, small particles.

Gases. Allergen gases are tougher to remove. Your best bet is to avoid generating potential allergens that are gases: Do not use aromatic candles or deodorizers; consider fresh air ventilation to pressurize your house with respect to your garage, attic, and the outdoors.

If you have allergies – especially if you are asthmatic – you probably already know what can hurt you. If your condition is severe, you probably have taken measures to protect your home environment.

If you are uncertain, trust and listen to your body … because healthy air matters!

Indoor air quality is complicated. It is best described as a perception, which is annoying to some and pleasing to others. In some cases, it relates to serious health effects for some but yet does not affect others.

Our indoor air quality discussion will include at least two aspects: odors and allergens. This article discusses odors. A future article will discuss allergens.

Indoor environments include many different odors. Some odors are pleasing. A cook takes delight in the smells of cooking. Fresh flowers offer pleasing fragrance.

Some odors are offensive. Spoilt food odors can be nauseous. Cleaning chemicals are irritating. Moldy odors are worrisome. Sulfurous odors are alarming.

Household odors represent many different sources. Each of us reacts differently to this odor cacophony.

Our sense of smell protects us from harm. Smell reveals conditions that are not otherwise evident. We become aware of good as well as danger. We associate some odors with safe food and secure conditions. We associate other odors with bad food and harmful conditions.

We smell (detect) odors at concentrations as low as one part per billion. Usually it takes a somewhat greater concentration to recognize (identify) an odor.

Our ability to first detect an odor is inherent, just as some people are short and others are tall; hence, some people smell an odor and others smell nothing. Our ability to identify odor is based upon association with individual experience; hence, one person describes an odor one way and another describes the same odor another way.

Odors are airborne contaminants; pure air is odorless. Because human sense of smell is so sensitive (low parts per billion), many common measurement meters cannot detect contaminations that are detectable by the human nose.

Airborne contaminants travel with air movement. Sometimes an odor is detected in the vicinity of the odor source; example, space within a cabinet or closet. Often air movement carries odors from sources within hidden spaces into living spaces; example, moldy odor from mold growing within a wall traveling into living spaces.

Investigating problem odors usually requires building diagnostics. Odor investigations can include multiple approaches:

• Understanding what-when-where the odor is present can allow an experienced investigator to identify prospective odor sources.
• High sensitivity meters can detect many volatile organic and formaldehyde in part per billion concentrations. Laboratory analyses can further identify many chemicals. Once detected or identified, chemicals can be associated with prospective household sources.
• Airborne mold spores can be readily measured. Moldy odors can travel through wall and ceiling spaces; in which case, prospective moisture sources suggest the mold growth source.
• Air movement patterns can frequently be identified with a smoke tube, an infrared camera, a blower door, or a combination of these techniques. Air flow pathways suggest prospective odor sources.

Your sense of smell detects the healthy and the harmful. If a home odor is questionable or offensive, the odor represents poor indoor air quality. Such odors may be associated with a harmful condition!

Your nose is a legitimate gauge of indoor air quality. Listen to your nose!

… because healthy air matters!

Acoustical comfort is a perception and relates to the level (intensity) and character (frequency) of sound. Acoustic discomfort might be caused by sounds that prevent normal conversation and peaceful rest, or are simply distractive … these are noises. For the purposes of this discussion, noise describes sound that is undesirable.

Indoor environments include distinctly different spaces with respect to sound. Media centers and music rooms need to contain sound without creating distortion. Living and family rooms and libraries need to allow normal conversation and contemplation. Sleeping areas need to allow peaceful rest. Acoustic comfort must accommodate all of these needs. Let’s discuss how this is approached.

First, let’s recognize: Sounds for some = noises for others …

Sound can be distractive (noise) even when the level (intensity) is not great. Examples include the rumble of a passing train (low frequency) or the punctuating sound of referee’s whistle (narrow frequency) over a roaring crowd (broad frequency; white noise).

Sometimes certain sounds can be distractive (noise) even when it’s quiet and regardless of frequency. For example, a barking dog bothers my wife and I hardly notice. A baby’s distant whimper alarms a mother; whereas the father’s TV concentration is unbroken.

Ensuring acoustic comfort requires considering all forms of sound. In order to attenuate (reduce) undesired sound (noise), the sound must first be measured. Sound level and frequency are measured with a meter such as illustrated in the adjacent photograph.

The illustrated meter is on my office desk with background Christmas music. Note the bar indicators on the screen. The center bars indicate sound levels at specific frequencies and the two far-right bars along with the value in the right corner represent overall sound level (59.4 decibels). The sound frequencies represent the range of normal human speech (singing). The overall sound level and frequencies are not distractive to me … hey, it’s Christmas music!

Having measured sound levels and frequencies, how do we specify noise abatement? We first need to understand noise measurements and how they relate to our hearing.

Decibel (dB). The decibel is the most commonly used measurement for sound level (intensity). Human perception of loudness varies based upon frequency. We cannot hear sounds with frequencies below about 20 Hertz) or above about 20,000 Hertz. We hear well within the frequency range of normal human speech, but our hearing diminishes below 1,000 Hertz and above 6,000 Hertz. Normal human conversation is between 500 Hertz and 6,000 Hertz (frequency) and at 60 decibels (intensity).

Perspective for sound levels in different setting is provided in the following table (http://www.engineeringtoolbox.com/sound-level-d_719.html):


Sone. Sone is a common specification for sound produced by fans, such as bathroom exhaust fans. Doubling the sones is equivalent to doubling the perceived sound level. [Adding six decibels is approximately equivalent to doubling the perceived sound level measured in decibels.]

Perspective for sound levels in different settings is provided in the adjacent table (http://www.designerhardware.com/files/HelpWin/Sone.html):

Once we know sound level and frequency, we can specify appropriate measures to attenuate (reduce) undesired sound (noise).

Sound Transmission Class (STC). This is a comparative measure of how well different materials attenuate sound. STC is used to specify materials or construction configurations that attenuate noise.

The following table offers perspective related to STC and sound attenuation (http://en.wikipedia.org/wiki/Sound_transmission_class):

I hope that you have caught that noise is not as simple as hearing; and, shutting out noise is not as simple as covering our ears. This article provides a simple overview of providing acoustical comfort for your indoor environment:

- Identify noise sources
- Measure sound level and frequency
- Determine acceptable sound levels
- Specify appropriate attenuation measures

Acoustic comfort is as critical to our indoor environment as hearing is to our human condition. Acoustic Comfort is peace and quiet … and affects your family’s enjoyment and wellbeing!