Forensic Engineers and Consultants

Archive: Subrogation

Stop or I’ll Soot!!!

Fire. Something about fire touches our brainstems…both good and bad!  Uncontrolled fire is terrifying and deadly to be sure.  But the controlled burning of wood at a campfire or in a fireplace in your home almost can’t be beat, to my mind! For that very reason, a fairly common amenity to houses nowadays is the gas log fireplace insert.

When not installed properly, these logs will generate soot. These soot particles can leave the fireplace and meander.  All. Over. Your. House.  Literally, if enough soot gets into the HVAC system, you can have soot in every room.  If the logs soot badly, you will notice right away and correct the problem.  It’s when the logs produce lesser amounts of soot that it will build up so slowly as to not be noticeable.  That is, until you adjust a picture frame and notice how dingy the wall has become.

It can cost tens of thousands of dollars to clean soot from a home.  Soot removal is a specialized restoration service that a typical homeowner cannot provide for themselves. Where there is soot, there is also carbon monoxide which can cause a host of physical ailments, as well. Prolonged exposure to soot can unleash a host of breathing problems, including asthma, bronchitis, and respiratory infections.

Fire Place with Gas LogsFigure 1: Properly aligned logs in a gas burning fireplace allow for a much better ambiance.

Why does this happen? Remember that combustion is a chemical reaction at its roots.  The clean, or complete, combustion you want in a furnace or stove results in that quintessential ‘blue’ flame. And in those applications, that is exactly the desired result; maximum efficiency and heat for heat transfer.  However, if the fuel-to-air ratio is modified, you can bring some yellow to the party and have a gas flame appear more like the flames generated by a wood fire. Still, the yellow Bunsen burner doesn’t draw you to sit down to bask in its output, does it?

Bunsen Burner

Figure 2.  Different fuel-to-air ratios dictate flame color in a decidedly unromantic Bunsen burner

Hence the gas log fireplace insert.  At the heart of it, a typical gas log fireplace insert is a burner that has the proper fuel-to-air ratio for either natural gas or propane to produce the yellow flame similar to a wood fire.  They also have ceramic ‘logs’ that are placed around the burner to further mimic the look of said wood fire.

The proper placement of the faux logs is critical to the safe operation of the fireplace, however.  From the front, the logs give the appearance of a stack of wood.  If you inspect the set from the top, however, the area around and above the burners is free from objects.  If the logs are not properly placed or get knocked out of place and get in the way of the flame from the burner, then impingement occurs.  The flame impinging on the ceramic log will cause soot to form.

Soot on a ceramic log placed improperly - WarrenFigure 3:  Soot on a ceramic log that was placed improperly. This condition can cause soot to spread throughout the house.

Therefore, when installing a gas fireplace insert follow the log placement instructions carefully!  If there is no glass in between the logs and whatever room they are in, it’s also not a bad idea to check the log placement when doing annual maintenance on your fireplace insert.

Jennifer Morningstar, PE, CFEI, has 19 years of industrial experience. Her areas of emphasis include chemical release & exposure, OSHA process safety management, industrial accident investigation, fires & explosions, and scope of damage/cost to repair analyses. She spent 16 years working at a polyethylene terephthalate (PET) manufacturer.  She is an OSHA-trained Process Hazard Analysis study leader and completed Root Cause Failure Analysis training to become an Incident Investigator. Jennifer authored procedures for lockout/tagout and confined space entry. She has experience as an energy management consultant in a variety of industries including mineral extraction, pulp & paper, animal harvesting & packaging (including rendering) and grain milling.  Jennifer holds a Bachelor of Science Degree in Chemical Engineering from Virginia Polytechnic Institute and State University as well as a Masters of Business Administration from the University of South Carolina.

Machine guard for blog

Machine Guarding and Risk Assessment

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The Occupational Health and Safety Administration (OSHA) “Top 10 for 2018” violations once again have Machine Safeguarding earning a position on the list. Machine safeguarding was the 9th most cited standard as noted in the list below:

  1. Fall protection, construction (29 CFR 1926.501)
  2. Hazard communication standard, general industry (29 CFR 1910.1200)
  3. Scaffolding, general requirements, construction (29 CFR 1926.451)
  4. Respiratory protection, general industry (29 CFR 1910.134)
  5. Control of hazardous energy (lockout/tagout), general industry (29 CFR 1910.147)
  6. Ladders, construction (29 CFR 1926.1053)]
  7. Powered industrial trucks, general industry (29 CFR 1910.178)
  8. Fall Protection–Training Requirements (29 CFR 1926.503
  9. Machinery and Machine Guarding, general requirements (29 CFR 1910.212)
  10. Eye and Face Protection (29 CFR 1926.102)

(Source: www.osha.gov/Top_Ten_Standards.html)

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Unguarded Shear point 1 white

Unguarded Shear Point on Force Tester Amputates Worker’s Finger

A worker was injured while testing gas springs similar to the type that hold the hatchback of an SUV open. The hazard that injured the worker was an unguarded shear point. The tester contained a mounting plate that was raised and lowered by a pneumatic cylinder.

The pneumatic cylinder lowered the mounting plate while the worker’s fingers were in the hazardous, unguarded shear point. Read More

Electric Hazard Guardrail photo

Hazards Can Lurk Anywhere … Watch Your Step …

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While on a lunch stop during a recent vacation trip through Tennessee, I happened across a safety hazard that required immediate attention.  The establishment had a raised concrete patio at the front with a steel railing around the perimeter.  At one edge of the patio was a set of stairs with a continuation of the steel railing used as a handrail.  The top edge of the patio had light strings wrapping the top metal bar as accent lighting for the perimeter.  The light string continued down the stair handrail wrapped in the same manner as the rest of the patio. Read More

Orange mini excavator

Case Study: Fatality Servicing Unsupported Excavator Boom

A mini-excavator at a job site developed a leak at a hydraulic fitting at the base of the cylinder that raises and lowers the boom. A subcontractor foreman at the site raised the boom to search for the leak. The foreman found and attempted to tighten the leaking fitting. When he did, the fitting separated from the base of the cylinder, releasing the hydraulic pressure that held the boom aloft. The boom fell and the bucket struck a nearby superintendent for the general contractor.

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Gas Appliance testing lab

Testing As Part of Gas Appliance Incident Investigation

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Equipment and appliances supplied with fuel gases like natural gas, propane and butane are a common and convenient part of most of our lives.  Such devices as gas grills and ranges, ovens, furnaces, space heaters and water heaters usually perform without incident.  However, when they malfunction the potential for incidents such as fires and explosions, carbon monoxide (CO) poisoning and burn injuries may occur. These incidents may be due to design and manufacturing defects in the product, or improper installation or operation of the device.

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3D Collision Impact Angle

Why investigators should have “Scaled Diagrams” of scenes?

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When it comes to diagramming a crash scene, there are several methods to complete the task. Forensic Mapping, (locating, positioning, and documenting the evidence of a collision scene to scale) is essential to having the answers to the questions “Who, What, Where, When, and Why”. Photographs do a great job showing what the investigators saw post collision; yet they lack scale and the ability to describe pre-collision movement. Having a computer aided diagram (CAD) of the collision scene goes much further than the pictures can; here is why.

basic intersectionA scale diagram gives the full overview of a collision scene from either a 2D or 3D point of view. Being able to see how things lined up, how they came together and how they parted helps explain the events within a crash. When a scene can be viewed from top down or any angle, that helps relay the facts. The investigator, judge, or jury will get Read More

Hot Tub Hazards

Danger Lurking in the Hot Tub

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Several dangers involving the use of a hot tub (spa) may readily come to mind, such as the risk of shock or electrocution, or the risk of drowning for unsupervised young children.  Not so readily apparent is the effect of overheating the human body, or “hyperthermia”.

Some individuals are more susceptible to the effects of hyperthermia, including the elderly, young children, and those in poor health.  The effects of hyperthermia, or overheating of the human body, cause direct responses such as headache, nausea, heat exhaustion, increased cardiac output, lethargy, confusion, heat stroke and unconsciousness.  The onset of hyperthermia is defined as being at 99.5° F; if the body temperature reaches 104° F, a life-threatening medical emergency exists.  Read More

box bailer

Defective Vertical Baler Causes Serious Crush Injury to Operator’s Arm

I recently worked on an interesting case involving a box baler. An employee of a butcher shop put some empty cardboard boxes in a vertical box baler and pushed the control switch to compact the boxes. After the 30 by 60 inch platen weighing 851 pounds returned to its raised position, the employee reached into the open space above the bottom door on the baler and began to clear cardboard from the bale tie slots in the bottom of the raised platen. Suddenly, and without warning, the steel pin attaching the platen to the raised hydraulic cylinder rod failed. The heavy steel platen fell and crushed his arm which was outstretched over the baler door into the compaction space.

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Under the sink chemicals

Not Your Father’s House Fire

Remember the good old days when our homes were built with only lumber, dry-wall, and roofing?   Me neither.  However, we talk about ‘modern’ construction materials like this is a new phenomenon.  The truth is ‘modern’ construction materials started sneaking into homes over fifty years ago.  It’s not only construction materials that have changed: a century ago, we furnished our houses with wood, cloth, metal, and glass. Today, it’s plastics, foams, and coatings.

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