Metal working safety

   / Metal working safety #31  
Outback,
You're on the right track by your awareness of metalworking hazards. It can be complicated, with hazards varying by type and severity depending on types of metals welded and the type of welding rod used. I did a considerable number of industrial hygiene surveys of welding/ cutting operations when I was employed as a Risk Control Consultant for one of the major insurance companies for 18 years. When I say complicated, I mean there are volumes of publications dedicated just to welding safety.

I cringe when I hear someone say something like "I've been doing this for 20 years and never wore a mask and I'm OK". To that I say FAMOUS LAST WORDS, as there are all too many people with disorders of the respiratory or central nervous system caused by exposure to welding hazards.

Here's what I would do: you can get a lot of competent free advice from your workers comp insurance company, OSHA, state worker safety outreach, maybe American Welding Society, local safety council office, maybe even suppliers.

Some operations are more dangerous than others. If you don't work with anything too exotic, your exposure could be minimal. Have you researched Material Safety Data Sheets (MSDS) for the metals or the rod? If not, do a google search for "MSDS Alloy 123" or whatever you're working with, and that will give you information about physical properties, health hazards, protective equipment needed, etc. suppliers of these materials are also required by law to provide an MSDS with the product if you request it.

That's all for now, i hope this info helps
 
   / Metal working safety #32  
I gave the 3m respirator a try while using the chop saw and after 7 minutes I had to take it off. It pulls down hard on the end of my nose, it interferes with my safety glasses leaveing a gap where a hot piece of metal can easily slip through into my eyes, and the inside of the mask fills up with moisture.


Seriously do welders really wear these respirators for 10 hours a day?


Think I'm going to make something like this over my welding table using a squirrel cage extractor fan.
welding_fume_extractor_ducting_squirrel_cage_fan.jpg
The answer is no, welder don't wear respirators when welding on carbon steel.
Maybe put a rheostat on the motor or at least a 2 or 3 speed fan as you may not always need to run it wide open. A small hood attached to the end would gather more smoke without the need for high air pull.
 
   / Metal working safety #33  
I was in a woodworking supply store today and noticed a rather large 'funnel' that is meant to attach to 4" dust collector ducting mainly for when using a miter saw.
In fact I would think that even the smallest capacity (CFM's) dust collectors would be just right for welding fume extraction.
Those smaller units run about $100. or so, run on 110VAC, use 4" ducting.
Just discard the dust bag and add outlet ducting.
For building exit use a clothes drier vent outlet.
Meant to suck sawdust but sure move a lot of air when not hauling dust.
The funnel (or cone) was about 16" X 16". and they also carried all sorts of flexible ducting.
Flexible for down line and rigid 4" ducting for outside venting.
A guy could rig up an effective fume system for about $200. or less 'borrowing' ideas from that industry.
They even have wireless switches that you could use as well for convenience.
 
   / Metal working safety #34  
Check into the fresh air masks for painters, there are full face and half masks. Some have there own pump, I used a half mask with a belted mounter filter which used air from your air compressor. These help keep you cool also.

If you have an oiled compressor, aren't you supposed to avoid breathing the air?
 
   / Metal working safety #35  
I think thats what the filter is for? Maybe thats why most have there own pump?

Dave
 
   / Metal working safety #36  
The tool and machine shop where I worked had lots of table specific exhaust fans... heating and cooling were not an issue in the mild Bay Area climate...

When I had to grind stainless tank flanges in the yard... I bought my own 3M respirator and used it... some of the guys gave me quite a ribbing for it and later, the company bought them for all of us...

We would also reline some special application friction materials...

Even today... with my hay fever... I will wear a respirator on the tractor in the spring and it does make a difference at night not being congested.

It's good to ask questions... no one will care as much as you... at least this was my reasoning when I bought my own respirator and hearing protection...
 
   / Metal working safety #37  
Hi Outback, et. al.,

At work in the urgent care, (and previously in the ER) I have mostly seen welders for flash burn, if they haven't been careful with their masks, and other metal workers for metal shavings, rust, or grit in the eye often with either foreign body implantation and/or corneal abrasions. The longer term consequences aren't in my current area of medicine, but I once had a patitent become disabled from long-term inhalation of cutting oil working in a metal shop where it was aerosolized. It caused fibrosis (scarring) in his lungs making it hard for them to expand to fill with air.

My brother-in-law, who had always had mild asthma, had to change jobs from welding because the metal fumes in the shops where he welded caused inflammation in his lungs. He welded professionaly on racing carts and rails.

Just for kicks, I did a couple of searches on a medical professional website (Medscape) using the search terms metal-working and welding and these are the items that came up.

Malignant Tumors of the Nasal Cavity:
Exposure to industrial fumes, wood dust, nickel-refining processes, and leather tanning may result in sinonasal malignancy and the development of septal perforation. Exposure to mineral oils, chromium, lacquer paint, soldering, and welding have also been associated with an increased incidence of sinonasal malignant tumors.

Lymphomas of the Head and Neck
Farming, welding, and work in the lumber industry are associated with an increased risk of lymphoma.

Phosgene Toxicity
Small-scale exposures to phosgene have also occurred, as phosgene is a product of thermal decomposition of chlorinated hydrocarbons.[6] Such agents include refrigeration coolants, dry cleaning fluids (carbon tetrachloride), metal degreasing agents (trichloroethylene), and paint strippers (methylene chloride).[7] When these chlorinated hydrocarbons are exposed to heat from a source such as a welding torch, a fire, or a heat gun, phosgene may be liberated.

Lead nephropathy
Environmental and occupational exposure to lead can cause chronic tubulointerstitial nephritis. Occupations in welding, smelting, the battery industry, and mining have all been responsible for lead nephropathy cases. Environmental exposure from leaded gasoline is decreasing, because the use of leaded gasoline has ceased in the United States; however, sporadic exposure is still observed, particularly among children living in deteriorating housing in urban areas. Rarely, lead poisoning can be observed among individuals who consume moonshine whiskey and those who drink beverages from imported ceramics painted with leaded glaze.

Beryllosis or Chronic Beryllium Poisoning:
Occupations with the highest potential for exposure to beryllium are those involved with primary production, metal machining, and reclaiming scrap alloys. Other high-exposure occupations are in the nuclear power, aerospace, and electronics industries. Some of the modern day uses of beryllium include the following:

Nuclear reactors and weapons
Inertial guidance systems
X-ray tube windows
Turbine rotor blades
Spark plugs
Laser tubes
Electrical components
Rocket engine liners
Ceramic applications
Springs, gears, aircraft brakes, aircraft engines, landing gear, and bearings
Oil and gas industries
Injection and blow mold tooling
Welding electrodes
Electrical contacts
Computer electronics
Automotive electronics
The number of industries that use beryllium is continuously expanding and the above list should not be viewed as exclusive. Beryllium has been used in a wide variety of products, including some bicycles and golf clubs.

Individuals using end products that contain beryllium, however, are not currently considered at risk for sensitization or disease. Only if the beryllium component is handled in a way that generates beryllium dust or particles (eg, sanding) would there be a risk.

Metal Fume Fever:
Metal fume fever (MFF) is a well-documented acute disease induced by intense inhalation of metal oxides. The exact pathophysiology is not well understood but likely involves the deposition of fine metal particulates in the alveoli, resulting in a self-limited syndrome of fever, myalgias, headache, and nausea 4-12 hours after exposure to metal fumes. MFF is primarily associated with the inhalation of HC fumes that are produced when zinc-oxide coated steel (galvanized) or zinc containing alloys (eg, brass) are exposed to high temperatures.

Keyes found that 1 in 5 welders has experienced MFF by age 30.[7] A study by Kuschner et al on human volunteers showed that pulmonary cytokines such as tumor necrosis factor (TNF), interleukin 6 (IL-6), and interleukin 8 (IL-8) may play important initial roles in mediating MFF.[8] Symptoms of MFF typically last several hours. Severe cases generally resolve in 1-2 days. Observation is usually all that is necessary.

The exact pathology of MFF is not well understood but likely involves the deposition of fine metal particulates in the alveoli. A study by Kuschner et al on human volunteers showed that pulmonary cytokines such as tumor necrosis factor (TNF), interleukin 6 (IL-6), and interleukin 8 (IL-8) may play important initial roles in mediating metal fume fever.

CBRNE - Lung-Damaging Agents, Toxic Smokes - NOx, HC, RP, FS, FM, SGF2, Teflon Clinical Presentation:
Causes

Sources

Oxides of nitrogen (NOx)

NOx are produced during electric or arc welding, combustion of fuels, detonation of nitrate-based explosives, combination of nitrogen-containing products, and decomposition of organic matter. Recently filled farm silos have high nitrogen dioxide levels for approximately 10 days, peaking at 4000 ppm. Significant quantities of nitrogen dioxide also are found in diesel engine exhaust.

Severe pulmonary reactions have been reported after unintentional exposures in unventilated farm silos, welding in confined spaces, detonating nitrogen-based explosives in enclosed spaces (tanks, ships), handling nitric acid, resurfacing ice arenas, using anesthesia, and in missile fuel oxidizer spills. Any person engaged in associated occupations or environments is at risk.

Zinc oxide (HC)

Since this smoke can be distributed by grenades, candles, pots, artillery shells, and special air bombs, any personnel engaged in the use or activity of these tools are at risk for HC exposure. Exposure to HC is also common among welders and those who are engaged in the melting of zinc.

Hypersensitivity Pneumonitis Presentation:
Metalworking fluid handlers, including those involved in the shaping of metal parts, are at risk of developing hypersensitivity pneumonitis from microbial contamination of metalworking fluids, (i.e., cutting oil or fluid), frequently with Mycobacterium immunogenum.

Background
Smoke inhalation injury was described as early as the first century CE, when Pliny reported the execution of prisoners by exposure to the smoke of greenwood fires. Smoke葉he vaporous colloidal system formed when a material undergoes combustion or pyrolysis幼omprises a collection of noxious gases, airborne solid particles, and airborne liquid particles. The distribution of those particles in the respiratory tract after inhalation is determined by their size and by the person痴 breathing mechanics and tidal volume.

During fires, smoke inhalation victims are unable to efficiently breathe through the nasopharynx, thereby decreasing inspiratory air filtration and enabling a greater amount of particle distribution in the airway. This subsequently leads to nasopharyngeal irritation and severe lung injury.

Inhalation injury from smoke in fires may account for as many as 60-80% of fire-related deaths in the United States, many of which are preventable.[4, 5] Excellent care rendered at today's burn centers has greatly reduced the mortality from surface burns,[6] while the mortality from pulmonary injury has been increasing.

Many victims of fire accidents have both smoke inhalation and thermal injury. In fact, the co-presence of bronchopulmonary injury with cutaneous burns that exceed 30% of the total body surface area causes the mortality rate to increase more than 70%.[7] Other studies have shown that the incidence of inhalation injury increases with increasing burn size.[2]

Smoke inhalation may produce injury through several mechanisms. Heated air from a fire can cause significant thermal injury to the upper airway. Particulate matter produced during combustion (soot) can mechanically obstruct and irritate the airways, causing reflex bronchoconstriction. Noxious gases released from burning materials include carbon monoxide (CO) and hydrogen cyanide.

Smoke may also contain aldehydes from combustion of furniture and cotton, and a variety of chemicals released by burning of rubber and plastics, including the following:

Chlorine gas
Ammonia
Hydrocarbons
Various acids
Ketones
Smokes and obscurants long have been used by the military as a means of hiding troops, equipment, and certain areas from view of the opposing forces and from engagement by weapons with electro-optical control systems. Although smokes typically are not used as direct chemical agents, they may produce toxic injury to skin, eyes, and all parts of the respiratory tract.[8] Smokes are also produced inadvertently in industry by explosion, by mechanical generation, or as a by-product of a chemical interaction.

Smokes associated with the military, industry, or both, include the following:

Oxides of nitrogen (NOx)
Zinc oxide (HC)
Red phosphorus (RP)
Sulfur trioxide (FS)
Titanium tetrachloride (FM)
Oil fog (eg, Smoke Generator Fog 2 [SGF2])
Pyrolysis of polytetrafluoroethylene (PTFE; Teflon)
The chemical property of smoke combined with burn injury induces a complex pathophysiologic process that results in hypoxic insult, early airway edema, and bronchoconstriction.[9]

Diagnosis of inhalation injury is not always straightforward, owing to poorly sensitive screening tests and, in many cases, the delay in manifestation of clinically significant symptoms until 24-72 hours after injury. In treatment of smoke inhalation, the most immediate concern is reversing cellular asphyxia and carbon monoxide (CO) and cyanide toxicity (see Treatment).

Exposure to metal fumes and fluorocarbons耀ystemic toxins typically released during industrial processes can cause inhalation toxicity.

Cyanogen chloride and cyanide poisoning
Cyanogen chloride (CK) is synthesized in the United States for industry by Matheson Tri-Gas and is used as an organic precursor and in mining and metalworking. Therefore, an emergency physician may be more likely to encounter cyanogen chloride (CK)貌xposed victims following an industrial accident rather than in a warfare or terrorism scenario.
 
   / Metal working safety #38  
"Studies have shown manganese fumes from welding can cause parkinsons disease."

Strange. Seems to be quite a few actors in Hollywood who have Parkinson's and they darn sure never set foot in a welding shop, much less worked in one.

No one said that welding was the only way that people develop Parkinson's Dz. There are many other factors and causes, including multiple mild traumatic brain injuries, i.e., punch drunk syndrome, like Mr. Ali.
 
   / Metal working safety #39  
When you google manganism, this is one of the first links to come up.

Manganism or Manganese Poisoning

At first glance it appears to be an informative website on the hazards of welding fumes, but then if you look in the upper left corner of the page notice the logo shows that the website is setup by a law office.

Reading that website scares the sh** out of me knowing I've been welding for 7 years without knowing the risk for developing parkinson disease.


The thing is if you google rare diseases, for example bacterial meningitis, you will find many stories of people who experienced the disease. When I google manganism there are no first hand stories from patients. It just does not seem as common as the propaganda websites make it seem.

Do any of you long time welders know coworkers who developed manganism or parkinsons disease?

Reguardless, I'm heading to the welding supply store to pickup a 3m 7502 respirator with 2091 cartridges and will wear is for welding and grinding.

Neurotoxins:
Neurotoxins may affect neurons, axons, or glial cells. They may cause metabolic imbalance that can secondarily affect the central nervous system (CNS). Some neurotoxins like manganese and MPTP have typical regional predilections. The following is a concise review of selected commonly encountered neurotoxins.

Metals
Metals have been known to be neurotoxic for centuries.

Contamination of groundwater with arsenic has been associated with epidemics of arsenic poisoning in some parts of south Asia.[4]

Increased awareness of lead toxicity over the past decades and regulations regarding the use of lead-based paints has decreased the incidence of lead toxicity.

Manganism was described as recently as 1989 in Taiwan.

Metals
Most reports of acute and chronic arsenic toxicity result from arsenic trioxide. In the United States, the drinking water standard for arsenic is 100 ppb.

Lead exists in 3 forms: metallic, inorganic, and organic. Lead is absorbed through the gastrointestinal tract or lungs. Approximately 99% of lead is in erythrocytes, and 1% is in plasma and serum. Lipid-rich tissue of the CNS is particularly sensitive to the organic form of lead. Leadç—´ ability to interfere with regulatory effects of calcium in cell systems may lead to its effect on voltage-gated channels and synaptic transmission.

Manganese is an essential trace element widely distributed in the environment. Most cases of manganese toxicity result from chronic inhalation of manganese dioxide.

Metals
Arsenic affects both motor and sensory peripheral nerves. Lead affects the motor nerves of upper and lower extremity. Acute lead poisoning can affect the CNS. Manganese can accumulate in globus pallidus and cause toxicity.

Metals
Arsenic causes a gastrointestinal disease characterized by vomiting and diarrhea, which may be followed by an encephalopathy with confusion, seizure, and coma. Chronic arsenic toxicity is a multisystem disease, characterized by sensorimotor polyneuropathy, skin changes, and alopecia.

The major target of lead toxicity is the peripheral nervous system in adults and CNS in children.[20] Intense toxicity may lead to an acute illness characterized by encephalopathy or an acute abdomen. Chronic lead exposure leads to predominantly motor neuropathy, affecting the upper extremity more than the lower. The minimum blood concentration needed is 10 ï½µg/dL in children and 40 ï½µg/dL in adults.

Initial signs and symptoms of manganese toxicity are nonspecific: headache, asthenia, somnolence, anorexia, and/or loss of sexual drive. Manganese causes an extrapyramidal syndrome characterized by progressive parkinsonism, dystonia, and neuropsychiatric symptoms (Manganese madness).[21] MRI shows a hyperintense T1 signal in the pallidum

Metals
Sural nerve biopsy in patients with arsenic poisoning shows axonal degeneration involving myelinated axons of all sizes with relative sparing of unmyelinated axons. Nerve biopsy in lead poisoning shows both axonal degeneration and segmental demyelination with prominent endoneural edema. Manganese encephalopathy is characterized by selective neuronal loss and gliosis in globus pallidus with relative sparing of the substantia nigra. There is also some involvement of the subthalamic nucleus and mamillary bodies.

Background
Some debate exists as to exactly what constitutes a "heavy metal" and which elements should properly be classified as such. Some authors have based the definition on atomic weight, others point to those metals with a specific gravity of greater than 4.0, or greater than 5.0. The actinides may or may not be included. Most recently, the term "heavy metal" has been used as a general term for those metals and semimetals with potential human or environmental toxicity.[1, 2] {{RE This definition includes a broad section of the periodic table under the rubric of interest.

Regardless of how one chooses to define the category, heavy metal toxicity is an uncommon diagnosis. With the possible exceptions of acute iron toxicity from intentional or unintentional ingestion and suspected lead exposure, emergency physicians will rarely be alerted to the possibility of metal exposure. Yet, if unrecognized or inappropriately treated, heavy metal exposure can result in significant morbidity and mortality. This article provides a brief overview of general principles in the diagnosis and management of metal toxicity. The Table reviews the typical presentation of the most commonly encountered metals and their treatment in summary form. It is not intended to guide clinical decision-making in specific cases.

Many of the elements that can be considered heavy metals have no known benefit for human physiology. Lead, mercury, and cadmium are prime examples of such "toxic metals." Yet, other metals are essential to human biochemical processes. For example, zinc is an important cofactor for several enzymatic reactions in the human body, vitamin B-12 has a cobalt atom at its core, and hemoglobin contains iron. Likewise, copper, manganese, selenium, chromium, and molybdenum are all trace elements, which are important in the human diet. Another subset of metals includes those used therapeutically in medicine; aluminum, bismuth, gold, gallium, lithium, and silver are all part of the medical armamentarium. Any of these elements may have pernicious effects if taken in quantity or if the usual mechanisms of elimination are impaired.

Exposure to metals may occur through the diet, from medications, from the environment, or in the course of work or play. Where heavy metal toxicity is suspected, time taken to perform a thorough dietary, occupational, and recreational history is time well spent, since identification and removal of the source of exposure is frequently the only therapy required.

A full dietary and lifestyle history may reveal hidden sources of metal exposure. Metals may be contaminants in dietary supplements, or they may leech into food and drink stores in metal containers like lead decanters. Persons intentionally taking colloidal metals for their purported health benefits may ultimately develop toxicity. Metal toxicity may complicate some forms of drug abuse. Beer drinkerç—´ cardiomyopathy was diagnosed in alcoholics in Quebec, and later Minnesota, during a brief period in the 1970s when cobalt was added to beer on tap to stabilize the head. More recently, a parkinsonian syndrome among Latvian injection drug users of methcathinone has been linked to manganese toxicity.

Manganese- acute exposure to fumes causes MFF, Chronic Exposure causes a Parkinson-like syndrome, with respiratory and neuropsychiatric impairments.

Nearly all organ systems are involved in heavy metal toxicity; however, the most commonly involved organ systems include the CNS, PNS, GI, hematopoietic, renal, and cardiovascular (CV). To a lesser extent, lead toxicity involves the musculoskeletal and reproductive systems. The organ systems affected and the severity of the toxicity vary with the particular heavy metal involved, the chronicity and extent of the exposure, and the age of the individual.

Parkinsonism-Dementia-ALS Complex
Parkinsonism – dementia – amyotrophic lateral sclerosis complex (PDALS) is a condition well described on the island of Guam and is known there as Lytico-Bodig disease. The latter term is derived from the local Guamanian dialect, with lytico referring to the paralysis caused by the ALS component and with bodig referring to the "laziness" that describes the parkinsonian component.

Extensive genetic and environmental research has been performed on this disorder in the last 50 years. The incidence of PDALS peaked in the 1950s and has declined since then. Dietary toxins in native flour were once considered the source of a potential neurotoxin. However, this hypothesis has been ruled out. The flour is obtained from the seeds of the cycad tree. Because the seed contains a potent hepatotoxin, the flour must be washed many times before consumption. Cycasin and beta-N -methyl-amino-L-alanine (BMAA) are putative neurotoxins in the seed. If the seeds are repeatedly washed, ingestion of an estimated 70 kg of flour is required to receive a toxic dose; therefore, this hypothesis is unlikely. Toxic effects of manganese and aluminum are also being considered.


That is all I could find re:manganese and parkinson's, and it does obviously suggest that ventilation is a key way to avoid metal toxicity.
 
   / Metal working safety #40  
Very few if any of these chemicals will be in contact with a welder who works on Carbon steel material only. CS has a very small amount of manganese in it to start with so a welder would need to inhale a heck of a lot of fumes in order to even be slightly approaching a THL of chemicals. I would be more afraid of any chemical contact with the material, like degreasers, that may produce fumes that are not so good for you. Basically if it smells bad or is irritating to the nose, I would take action to eliminate it. Lead and zinc contamination is the most frequent culprit to damaging a person in the metal trades.

Proper PPE (personal protective equipment) is essential when handling or welding on any product. Most times this is just leather gloves and a welding hood with proper shade of lens, or it could mean fresh air mask (not from a compressor with oiled bearings), fully enclosed suit to prevent any contact (similar to a biohazard suit) but this is very rare in the metal trades and requires special training to use.

As you stated, ventilation is the key to any contamination issues. Proper smoke removal, even if it is just an open door with air mover of any type with cross ventilation is basically all that is needed for normal welding operations on carbon steel.
 
 
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