Category: Chemical & Disease Updates

Updates on chemical and disease info

Cresol / Cresylic Acid – Guide to Hazardous Air Pollutants used by the Irish Air Corps

Cresol / Cresylic Acid

o-CRESOL, m-CRESOL, p-CRESOL

Cresylic Acid spilled all over the floor of the NDT shop of ERF and indeed dribbling down the wall from the extractor fan.

CAS  1319-77-3 , 95-48-7, 108-39-4, 106-44-5

Hazard Summary

Ambient air contains low levels of cresols from automobile exhaust, power plants, and oil refineries. Acute (short-term) inhalation exposure by humans to mixed cresols results in respiratory tract irritation, with symptoms such as dryness, nasal constriction, and throat irritation.  Mixed cresols are also strong dermal irritants.

No information is available on the chronic (long-term) effects of mixed cresols in humans, while animal studies have reported effects on the blood, liver, kidney, and central nervous system (CNS), and reduced body weight, from oral and inhalation exposure to mixed cresols.

Several animal studies suggest that o-cresol, m-cresol, and p-cresol may act as tumor promotors.  EPA has classified o-cresol, m-cresol, and p-cresol as Group C, possible human carcinogens.

Please Note: The main sources of information for this fact sheet are EPA's IRIS (4), which contains information on oral chronic toxicity and the RfD, and the carcinogenic effects of cresols, and the Agency for Toxic Substances and Disease Registry's (ATSDR's) Toxicological Profile for Cresols. (1)

Uses

  • Mixed cresols are used as disinfectants, preservatives, and wood preservatives. (1)
  • o-Cresol is used as a solvent, disinfectant, and chemical intermediate. (1)
  • m-Cresol is used to produce certain herbicides, as a precursor to the pyrethroid insecticides, to produce antioxidants, and to manufacture the explosive, 2,4,6-nitro-m-cresol. (1)
  • p-Cresol is used largely in the formulation of antioxidants and in the fragrance and dye industries. (1)

Sources and Potential Exposure

  • Mixed cresols may be found in ambient air; sources are car exhaust, electrical power plants, municipal solid waste incinerators, oil refineries, and cigarettes. (1)
  • People in residential areas where homes are heated with coal, oil, or wood may be exposed to mixed cresols in the air. (1)
  • Some foods, such as tomatoes, ketchup, asparagus, cheeses, butter, bacon, and smoked foods, as well as beverages, such as red wine, raw and roasted coffee and black tea, contain mixed cresols. (1)
  • Occupational exposure to mixed cresols may also occur at workplaces where mixed cresols and/or cresol containing products are produced or used. (1)

Assessing Personal Exposure

  • Mixed cresols can be measured in the urine of exposed individuals.

Health Hazard Information

Acute Effects:

  • Acute inhalation exposure by humans to mixed cresols results in respiratory tract irritation, with symptoms such as dryness, nasal constriction, and throat irritation.  Mixed cresols are also strong dermal irritants. Ingestion of high levels of mixed cresols by humans has resulted in effects on the respiratory system, gastrointestinal system, blood, liver, kidney, and CNS. (1,2)
  • Animal studies have reported respiratory tract and eye irritation, and effects on the liver, kidney, and CNS from acute inhalation exposure to mixed cresols. (1)
  • Acute animal tests in rats have shown mixed cresols to have moderate acute toxicity, while o-cresol, m-cresol, and p-cresol have been shown to have high acute toxicity from oral exposure. (3)

Chronic Effects (Noncancer):

  • No information is available on the chronic effects of mixed cresols in humans. (1)
  • Animal studies have reported effects on the blood, liver, kidney, and CNS, as well as reduced body weight, from oral and inhalation exposure to mixed cresols. (1,5)
  • EPA has not established a Reference Concentration (RfC) or a Reference Dose (RfD) for mixed cresols. (4)
  • The California Environmental Protection Agency 3  (CalEPA) has established a chronic reference exposure level of 0.004 milligrams per cubic meter (mg/m ) for mixed cresols based on bone marrow effects in rats. The CalEPA reference exposure level is a concentration at or below which adverse health effects are not likely to occur. It is not a direct estimator of risk, but rather a reference point to gauge the potential effects. At lifetime exposures increasingly greater than the reference exposure level, the potential for adverse health effects increases. (5)
  • EPA has not established an RfC for o-, m-, or p-cresol.  (5-7)
  • The RfD for o-cresol and m-cresol is 0.05 milligrams per kilogram body weight per day (mg/kg/d) based on decreased body weights and neurotoxicity in rats. The RfD is an estimate (with uncertainty spanning
    perhaps an order of magnitude) of a daily oral exposure to the human population (including sensitive subgroups) that is likely to be without appreciable risk of deleterious noncancer effects during a lifetime. (5,6)
  • EPA has high confidence in the studies on which the RfDs are based because they provided adequate toxicological endpoints that included both general toxicity and neurotoxicity; medium confidence in the database because there are adequate supporting subchronic studies but lacking chronic toxicity and reproductive studies; and, consequently, medium confidence in the RfD. (5,6)
  • The provisional RfD for p-cresol is 0.005 mg/kg/d based on neurological and respiratory effects in rabbits. The provisional RfD is a value that has had some form of Agency review, but it does not appear on IRIS. (8)

Reproductive/Developmental Effects:

  • No information is available on the reproductive or developmental effects of mixed cresols in humans. (1)
  • Animal studies have reported developmental effects, but only at maternally toxic doses, and no reproductive effects from oral exposure to mixed cresols. (1)

Cancer Risk:

  • Only anecdotal information is available on the carcinogenic effects of mixed cresols in humans. (4-7)
  • The only available oral animal study is a 13-week study that suggested that p-cresol may act as a promotor for tumors of the forestomach. (1)
  • Several dermal animal studies have suggested that o-cresol, m-cresol, and p-cresol may act as tumor promotors. (1,4-7)
  • EPA has classified o-cresol, m-cresol, and p-cresol as Group C, possible human carcinogens. (5-7)

Physical Properties

  • Mixed cresols are colorless solids, but usually they occur as a brown liquid mixture. (1)
  • Mixed cresols have a medicinal odor; the odor thresold for m-cresol is 0.00028 parts per million (ppm). (1,9)
  • The chemical formula for cresol is C 7 H 8 O, and the molecular weight is 108.14 g/mol. (1)
  • The primary synonym for o-cresol is 2-methylphenol; m-cresol is 3-methylphenol, and p-cresol is 4-methylphenol. (5-7)
  • The vapor pressures, at 25 °C, for o-cresol, m-cresol, and p-cresol are 0.299 mm Hg, 0.138 mm Hg, and 0.11 mm Hg, respectively. (1)
  • The octanol/water partition coefficients (log K ow) for o-cresol, m-cresol, and p-cresol are 1.95, 1.96, and 1.94, respectively. (1)

Read the full EPA PDF on the above Hazardous Air Pollutant with references below.

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Relavance to personnel who served in the Air Corps

  1. Cresylic Acid is  component of Ardrox 666
  2. Cresols are consitituent chemicals of turbine engine oils. e.g. Tri-cresyl phosphate which is an organophosphate.

There are likely many more chemicals used by the Air Corps that contain Benzene. If you know of some let us know in the comments section.

Benzene – Guide to Hazardous Air Pollutants used by the Irish Air Corps

Benzene

CAS  71-43.2

Hazard Summary

Benzene is found in the air from emissions from burning coal and oil, gasoline service stations, and motor vehicle exhaust. Acute (short-term) inhalation exposure of humans to benzene may cause drowsiness,  dizziness, headaches, as well as eye, skin, and respiratory tract irritation, and, at high levels, unconsciousness. Chronic (long-term) inhalation exposure has caused various disorders in the blood, including reduced numbers of red blood cells and aplastic anemia, in occupational settings.   Reproductive effects have been reported for women exposed by inhalation to high levels, and adverse effects on the developing fetus have been observed in animal tests. Increased incidence of leukemia (cancer of the tissues that form white blood cells) have been observed in humans occupationally exposed to benzene. EPA has classified benzene as known human carcinogen for all routes of exposure.

Please Note: The main sources of information for this fact sheet are the Agency for Toxic Substances and Disease Registry's (ATSDR's) Toxicological Profile for Benzene (1) and EPA's Integrated Risk Information System (IRIS) (4),which contains information on the health effects of benzene including the unit cancer risk for inhalation
exposure.

Uses

  • Benzene is used as a constituent in motor fuels; as a solvent for fats, waxes, resins, oils, inks, paints, plastics, and rubber; in the extraction of oils from seeds and nuts; and in photogravure printing. It is also used as a chemical intermediate. Benzene is also used in the manufacture of detergents, explosives, pharmaceuticals, and dyestuffs. (1,2,6)

Sources and Potential Exposure

  • Individuals employed in industries that manufacture or use benzene may be exposed to the highest levels of benzene. (1)
  • Benzene is found in emissions from burning coal and oil, motor vehicle exhaust, and evaporation from gasoline service stations and in industrial solvents. These sources contribute to elevated levels of benzene in the ambient air, which may subsequently be breathed by the public. (1)
  • Tobacco smoke contains benzene and accounts for nearly half the national exposure to benzene. (1)
  • Individuals may also be exposed to benzene by consuming contaminated water. (1)

Assessing Personal Exposure

Measurement of benzene in an individual’s breath or blood or the measurement of breakdown products in the urine (phenol) can estimate personal exposure. However, the tests must be done shortly after exposure
and are not helpful for measuring low levels of benzene. (1)

Health Hazard Information

Acute Effects:

  • Coexposure to benzene with ethanol (e.g., alcoholic beverages) can increase benzene toxicity in humans. (1)
  • Neurological symptoms of inhalation exposure to benzene include drowsiness, dizziness, headaches, and Neurological symptoms of inhalation exposure to benzene include drowsiness, dizziness, headaches, and unconsciousness in humans.  Ingestion of large amounts of benzene may result in vomiting, dizziness, and convulsions in humans. (1)
  • Exposure to liquid and vapor may irritate the skin, eyes, and upper respiratory tract in humans.  Redness and blisters may result from dermal exposure to benzene. (1,2)
  • Animal studies show neurologic, immunologic, and hematologic effects from inhalation and oral exposure to benzene. (1)
  • Tests involving acute exposure of rats, mice, rabbits, and guinea pigs have demonstrated benzene to have low acute toxicity from inhalation, moderate acute toxicity from ingestion, and low or moderate acute toxicity from dermal exposure. (3)
  • The reference concentration for benzene is 0.03 mg/m3 based on hematological effects in humans. The RfC is an estimate (with uncertainty spanning perhaps an order of magnitude) of a continuous inhalation
    exposure to the human population (including sensitive groups) that is likely to be without appreciable risk deleterious noncancer effects over a lifetime. (4)

Chronic Effects (Noncancer):

  • Chronic inhalation of certain levels of benzene causes disorders in the blood in humans. Benzene specifically affects bone marrow (the tissues that produce blood cells). Aplastic anemia (a risk factor for acute nonlymphocytic leukemia), excessive bleeding, and damage to the immune system (by changes in blood levels of antibodies and loss of white blood cells) may develop. (1)
  • In animals, chronic inhalation and oral exposure to benzene produces the same effects as seen in humans. (1)
  • Benzene causes both structural and numerical chromosomal aberrations in humans. (1)
  • EPA has established an oral Reference Dose (RfD) for benzene of 0.004 milligrams per kilogram per day (mg/kg/d) based on hematological effects in humans. The RfD is an estimate (with uncertainty spanning perhaps an order of magnitude) of a daily oral exposure to the human population (including sensitive subgroups) that is likely to be without appreciable risk of deleterious noncancer effects during a lifetime. It is not a direct estimator of risk, but rather a reference point to gauge the potential for effects. At exposures increasingly greater than the RfD, the potential for adverse health effects increases. Lifetime exposure above the RfD does not imply that an adverse health effect would necessarily occur. (4)
  • EPA has established a Reference Concentration (RfC) of 0.03 milligrams per cubic meter (0.03 mg/m3) for benzene based on hematological effects in humans. The RfC is an inhalation exposure concentration at or below which adverse health effects are not likely to occur. It is not a direct estimator of risk, but rather a reference point to gauge the potential for effects. At lifetime exposures increasingly greater than the reference exposure level, the potential for adverse health effects increases. (4)

Reproductive/Developmental Effects:

  • There is some evidence from human epidemiological studies of reproductive and developmental toxicity of benzene, however the data do not provide conclusive evidence of a link between exposure and effect. (4)
    Animal studies have provided limited evidence that exposure to benzene may affect reproductive organs, however these effects were only observed at exposure levels over the maximum tolerated dose. (4)
  • Adverse effects on the fetus, including low birth weight, delayed bone formation, and bone marrow damage, have been observed where pregnant animals were exposed to benzene by inhalation.(4)

Cancer Risk:

  • Increased incidence of leukemia (cancer of the tissues that form white blood cells) has been observed in humans occupationally exposed to benzene. (1,4)
  • EPA has classified benzene as a Group A, known human carcinogen. (4)
  • EPA uses mathematical models, based on human and animal studies,to estimate the probability of a person developing cancer from breathing air containing a specified concentration of a chemical. EPA calculated a range of 2.2 x 10 -6  to 7.8 x 10 -6  as the increase in the lifetime risk of an individual who is continuously exposed to 1 µg/m3 of benzene in the air over their lifetime.
  • EPA estimates that, if an individual were to continuously breathe the air containing benzene at an average of 0.13 to 0.45 µg/m 3  (1.3×10 -4  to 4.5x -4mg/m 3 ) over his or her entire lifetime, that person would theoretically have no more than a one-in-a-million increased chance of developing cancer as a direct result of continuously breathing air containing this chemical. Similarly, EPA estimates that continuously breathing air containing 1.3 to 4.5 µg/m 3 (1.3×10 -3  to 4.5×10 -3  mg/m 3 ) would result in not greater than a one-in-ahundred thousand increased chance of developing cancer, and air containing 13 to 45 µg/m3  (1.3 x 10 – 2  to 4.5 x 10-2 mg/m3) would result in not greater than a one-in-ten thousand increased chance of developing cancer. For a detailed discussion of confidence in the potency estimates, please see IRIS.(4)
  • EPA has calculated an oral cancer slope factor ranging from 1.5 x 10-2  to 5.5 x 10 -2 (mg/kg/d)-1  that is an extrapolation from inhalation dose-response data. (4)

Physical Properties

  • The chemical formula for benzene is C6H6, and it has a molecular weight of 78.11 g/mol. 4) Benzene occurs as a volatile, colorless, highly flammable liquid that dissolves easily in water. (1,7)
  • Benzene has a sweet odor with an ASTDR reported odor threshold of 1.5 ppm (5 mg/m3).
  • The vapor pressure for benzene is 95.2 mm Hg at 25 °C, and it has a log octanol/water partition coefficient (log Kow) of 2.13. (1)

Read the full EPA PDF on the above Hazardous Air Pollutant with references below.

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Relavance to personnel who served in the Air Corps

  1. Benzene is a component of Jet A1 (AVTUR) and/or Jet A1 exhaust 
  2. Benzene is a component of 100LL (AVGAS) and/or 100LL exhaust
  3. Cellulose Thinners used in spray painting contain Benzene
  4. Akzo Nobel Hardner S66/22R contains <25% Benzene
  5. Mastinox 6856k contains 1-3% Benzene

There are likely many more chemicals used by the Air Corps that contain Benzene. If you know of some let us know in the comments section.

Asbestos – Guide to Hazardous Air Pollutants used by the Irish Air Corps

Asbestos

CAS  1332-21-4

Hazard Summary

Asbestos production and use has decreased dramatically over the years in the United States. Exposure to asbestos may occur from ambient air, indoor air, or water. Effects on the lung are a major health concern from asbestos, as chronic (long-term) exposure to asbestos in humans via inhalation can result in a lung disease termed asbestosis. Asbestosis is characterized by shortness of breath and cough and may lead to severe impairment of respiratory function. Cancer is also a major concern associated with asbestos exposure, as inhalation exposure causes lung cancer and mesothelioma (a rare cancer of the thin membranes lining the abdominal cavity and surrounding internal organs), and possibly stomach, laryngeal, and colorectal cancer. EPA has classified asbestos as a Group A, known human carcinogen.

Please Note: The main sources of information for this fact sheet are EPA's Integrated Risk Information System (IRIS) (2), which contains information on the carcinogenic effects of asbestos including the unit cancer risk for inhalation exposure, and the Agency for Toxic Substances and Disease Registry's (ATSDR's) Toxicological Profile for Asbestos. (1)

Uses

  • Asbestos production and use in the U.S. has decreased dramatically over the years due to healthconcerns and regulations banning its use. (1)
  • U.S. production of asbestos decreased from 300 million pounds in 1973 to 6 million pounds in 2002. (3)
  • In 2010, there were two U.S. suppliers of asbestos and most of the asbestos used in the U.S. is imported from Canada. (3)
  • Asbestos has been used in building materials, paper products, asbestos-cement products, friction products, textiles, packings and gaskets, and asbestos-reinforced plastics. (1,4)
  • Many uses have been prohibited, including the spraying of asbestos-containing material on buildings and structures for fireproofing, insulation and decorative purposes, asbestos inclusion in patching compounds and asbestos heat shields in hair dryers. Asbestos substitutes continue to be developed. For example, nonasbestos friction materials are currently being used in disc brake pads, and substitutes have been developed for drum brake linings. (1)

Sources and Potential Exposure

  • Airborne exposure to asbestos may occur through the erosion of natural deposits in asbestos bearing rocks, from a variety of asbestos-related industries, or from clutches and brakes on cars and trucks. The concentrations in outdoor air are highly variable. (1,4)
  • Asbestos has been detected in indoor air, where it is released from a variety of building materials such as insulation and ceiling and floor tiles. It is only released, however, when these building materials are damaged or disintegrate. (1)
  • Asbestos may be released into water from a number of sources, including erosion of natural deposits, corrosion from asbestos-cement pipes, and disintegration of asbestos roofing materials with subsequent transport into sewers. (1,4)

Health Hazard Information

Acute Effects:

  • No studies were located on the acute (short-term) toxicity of asbestos in animals or humans. (1)

Chronic Effects (Noncancer):

  • Chronic inhalation exposure to asbestos in humans can lead to a lung disease called asbestosis, which consists of a diffuse fibrous scarring of the lungs. Symptoms of asbestosis include shortness of breath, difficulty in breathing, and coughing. Asbestosis is a progressive disease, i.e., the severity of symptoms tends to increase with time, even after the exposure has stopped. In severe cases, this disease can lead to death, due to impairment of respiratory function. (1,2)
  • Other effects from asbestos exposure via inhalation in humans include pulmonary hypertension and immunological effects. (1,2)
  • Feeding studies in animals exposed to high doses of asbestos have not detected any evidence of adverse toxic effects. (1,2)
  • EPA has not established a Reference Concentration (RfC) or a Reference Dose (RfD) for asbestos. (2)

Reproductive/Developmental Effects:

  • No studies were located on the developmental or reproductive effects of asbestos in animals or humans via inhalation. (1)
  • Birth defects were not noted in the offspring of animals exposed to asbestos in the diet during pregnancy. (1)
  • No effects on fertility were observed in animals exposed to asbestos in the diet during breeding, pregnancy, and lactation. (1)

Cancer Risk:

  • A large number of occupational studies have reported that exposure to asbestos via inhalationcauses lung cancer and mesothelioma (a rare cancer of the membranes lining the abdominal cavity and surrounding internal organs). (1,2,3)
  • Individuals who smoke and are also exposed to asbestos have a greater than additive increased risk of developing lung cancer. (1,2,3)
  •  Long and intermediate-range asbestos fibers (>5 micrometers (µm)) appear to be more carcinogenic than short fibers (<5 µm). (1)
  • Some occupational studies have reported an increased risk of stomach, laryngeal, or colorectal cancer from asbestos exposure. However, the data are not as strong as that for lung cancer and mesothelioma. (1)
  • Epidemiological studies have not found a clear association between asbestos exposure in drinking water and an increased risk of stomach cancer. (1,2,3)
  • A series of large-scale lifetime feeding studies in animals reported that exposure to intermediate-range asbestos fibers increased the incidence of a benign tumor of the large intestine in male rats, while short-range asbestos fibers showed no significant increase in tumor incidence. (1)
  • EPA has classified asbestos as Group A, human carcinogen. (2)
  • EPA uses mathematical models, based on human and animal studies, to estimate the probability of a person developing cancer from breathing air containing a specified concentration of a chemical. EPA calculated an inhalation unit risk estimate of 2.3 × 10-1 (fibers/cm3)-1. EPA eestimates that, if an individual were to continuously breathe air containing asbestos at an average of 0.000004 fibers/cm3 over his or her entire lifetime, that person would theoretically have no more than a one-in-a-million  increased chance of developing cancer as a direct result of breathing air containing this chemical. Similarly, EPA estimates that breathing air containing 0.00004 fibers/cm3 would result in not greater than a one-in-a-hundred thousand increased chance of developing cancer, and air containing 0.0004 fibers/cm3 would result in not greater than a one-in-ten-thousand increased chance of developing cancer. (2)

Physical Properties

  • Asbestos is the name applied to a group of six different fibrous silicate minerals that occur naturally in the environment. (1)
  • There are two groups of asbestos minerals: serpentine and amphibole. There are also nonfibrous forms of serpentine and amphibole which are not asbestos. (1)
  • Serpentine asbestos are relatively long and flexible crystalline fibers that may be woven, and includes the mineral chrysotile, and amphibole asbestos are more brittle than serpentine asbestos and includes the minerals amosite, crocidolite, tremolite, anthophyllite, and actinolite. (1)
  • Asbestos is neither volatile nor soluble; however, small fibers may occur in suspension in both air and water. (1)

Read the full EPA PDF on the above Hazardous Air Pollutant with references below.

*****

Relavance to personnel who served in the Air Corps

  1. Pipework in a number of Air Corps buildings was lagged with Asbestos most notably the Apprentice hostel was lagged with badly damaged Asbestos until the early 1990s. So every apprentice who served from approximately the 55th Apprentice Class and before was exposed to asbestos in their sleeping environment.
  2. The apprentice hangar roof was made from asbestos.
  3. Parts of engine shop ceiling was discovered to be made from asbestos when it partially collapsed and dislocated the shoulder of a machinist working beneath it.
  4. The fire crew wore special fire suits made from asbestos. 

It is likely that we have missed many areas of asbestos usage  in both Baldonnel and Gormanston aerodromes so please help us by listing usage locations in comments section below.

Illnesses linked to Trichloroethylene (TCE)

Illnesses linked to Trichloroethylene (TCE) aka TRIKE

https://www.healthandenvironment.org/our-work/toxicant-and-disease-database/?showcategory=&showdisease=&showcontaminant=2341&showcas=&showkeyword=

Solvent exposure and Parkinson’s disease

Shaun Wood worked was a painter and finisher  at Royal Air Force (RAF) bases across the world. During the early 1990s he was involved in the very intensive work preparing Tornado aircraft for the first Gulf War, in particular gluing anti-missile patches to the aircraft. This work was often done in confined spaces over long working hours.  He generally wore a respirator but these were not really adequate for the circumstances.

German Tornado Undergoing Maintenance

Shaun has been diagnosed with Multiple System Atrophy (MSA), which is a debilitating Parkinsonian syndrome that affects the nervous system. He is just 53 years of age.

Throughout his work Shaun was exposed to various solvents, but primarily trichloroethylene and dichloromethane. There is not a great deal of information about exposure to these solvents in aircraft maintenance. I have seen results from a survey carried out at an RAF base in Scotland where dichloromethane levels were measured during paint striping in the cockpit area of a Nimrod aircraft. There was only 1.5 m2 of paint removed, but the peak air concentrations were about 700 mg/m3. Results from three monitoring surveys where the British Health and Safety Executive sampled for dichloromethane during paint stripping on aircraft are shown in the following figure. The mean levels measured in each of these surveys were: 330, 790 and 1,960 mg/m3, and the highest individual level measured was 3,590 mg/m3.

Read full article on OH-world.org A blog about exposure science and occupational hygiene

http://johncherrie.blogspot.ie/2011/12/solvent-exposure-and-parkinsons-disease.html

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Below is a photo of one of the locations in the Irish Air Corps that used Dichloromethane, namely the NDT Shop of Engine Repair Flight. Yes that is a stream of the chemicals dripping out of the extractor fan and running down the wall. And yes that is dichloromethane, cresylic acid and the hexavalent sodium chromate all over the floor. The small barrel that is being dissolved by its contents contains Hydrofluoric Acid.

Some extracts from the Ambient Air Monitoring For Health and Safety at Work report dated 2nd August 1995

  1. Dichloromethane levels were measured in the engine shop in Wednesday the 12th and Thursday the 13th of July 1995 at the behest of Captain John Maloney who is still serving in the Irish Air Corps
  2. The level of dichloromethane found in ambient air in the engine
    cleaning area exceeded health and safety limits. 
  3. Levels of Dichloromethane were measured at 175.9ppm (622.5 mg/m3)  while the TWA health & safety limit for this chemical in 1995 was 50ppm.
  4. Significant levels of all parameters monitored were found in nearly all ambient air samples taken in the engine cleaning area.
  5. The ventilation in all areas monitored was deemed to be insufficient. It is thus recommended that mechanical heating and ventilation systems be adapted designed and installed in all areas monitored.

To summarise, the Irish Army Air Corps knew that Dichloromethane levels in the NDT shop in 1995 exceeded health & safety limits by 3.5 times yet officer management…

  1. LEFT personnel of all ranks and none to rot in this exceptionally toxic working environment for a further 12 years.
  2. IGNORED the recommendation to design and install design a proper ventilation system, (they stuck in 2 x Xpelairs).
  3. NEVER re-tested the environment to see if the Xpelair fans worked, we suspect they made things worse by increasing evaporation rate.
  4. NEVER informed personnel of enlisted ranks that their workplace was contaminated to dangerous levels.

DELAY – DENY – DIE

Hexamethylene Diisocyanate – Just one of the toxic chemicals the Irish Air Corps and State Claims Agency want to hide from former personnel!

  1. Exposure can occur when isocyanates are curing or when cured isocyanates are heated.
  2. An individual’s response to isocyanate exposure can be immediate or may be DELAYED FOR SEVERAL YEARS.
  3. Skin exposure can also cause respiratory sensitisation.
  4. The odour threshold for isocyanates, i.e. the level at which an individual can smell an isocyanate, is typically higher than the allowed exposure limits.
  5. The Air Corps did eventually provide a “supplied air” respirator to spray paint & welding personnel. Unfortunately they sourced the “supplied air” from an old machine compressor located in ERF where the air had previously tested as 3.5 times over the allowed limit for Dichloromethane i.e. allowed limit was 50ppm and sourced air was from a location measured at 175ppm…out of the frying pan and into the fire.

Air Corps Hexamethylene Diisocyanate Usage

Hexamethylene Diisocyanates were a chemical component of polyurethane paint hardener used by the Spray Paint Shop (Dope Shop) at Baldonnel. For most of the existence of this shop personnel were NOT supplied with ANY PPE. The walls between the Spray Paint Shop and Engineering Wing Hangar & Workshops were not sealed and so Hexamethylene Diisocyanate and other chemicals entered these workplaces whilst spraying was in progress exposing all personnel.

Furthermore if a component could not be removed from an aircraft for spray painting it was spray painted in-situ in Engineering Wing Hangar whilst unprotected line & tech personnel worked in adjoining offices & workshops or on other aircraft in the hangar.

Visiting personnel to Engineering Wing hangar such as BFTS personnel doing an IRAN, Heli personnel doing an overhaul & even Military Police on a walkabout were also exposed.

A “waterfall” system with an extractor fan was also present. Personnel spray painted aircraft components toward the waterfall which captured most of the over-spray droplets. Fumes from this waterfall were then extracted by a fan, up a duct and released at approximately 3m height where the prevailing winds then carried the extracted fumes in the doors & windows of : 

  • 5th Maintenance Engineers
  • Air Corps Apprentice School
  • Avionics Squadron
  • BFW Stores
  • Engine Repair Flight
  • Old Tech Stores
  • Training Wing HQ Prefab
  • Parachute Shop

5-20% of people are prone to isocyanate sensitisation. and isocyanate cross sensitisation is a recognised phenomenon. Sensitisation is irreversible and unfortunately once sensitised it is next to impossible to avoid isocyanate allergy triggers in the modern environment as they are used to make all Polyurethane products.

It is also likely that health effects are suffered beyond the respiratory system & skin for example the gastric & nervous systems and it is also probable that sensitisation to isocyanates will lead to allergies to other unrelated chemicals leading to a cascade of triggering chemicals allergies & intolerance for over exposed individuals.

DELAY – DENY – DIE

Safe Handling of Cresols, Xylenols & Cresylic Acids

Introduction

Cresols, xylenols and cresylic acids are hazardous substances and dangerous both to people and the environment if handled improperly. Cresols, xylenols and cresylic acid products produced by Sasol Chemicals (USA) LLC are highly versatile materials and are used as intermediates in the manufacture of a wide variety of industrial products such as resins, flame retardants, antioxidants, and coatings. In these and other applications, cresylic acids can be stored, transferred, processed and disposed of safely when proper procedures and safeguards are used. 

“Cresol” refers to any of the three isomers of methylphenol (C7H8O) or combinations thereof. “Cresols” commonly refer to a mixture which is predominantly methylphenol but may also contain lesser amounts of other alkylphenols. “Xylenol” is a common name for any of the six isomers of dimethylphenol (C8H10O) or their various combinations. Material which is predominantly dimethylphenol but which also contains ethylphenols and other alkylphenols may be referred to as “Xylenols”. “Cresylic acid” is a generic term referring to various combinations of cresols, xylenols, phenol or other alkylphenols (ethylphenols, propylphenols, trimethylphenols, etc.). 

Purpose & Scope

The purpose of this document is to provide information gathered through Sasol’s long experience in the safe handling of cresylic acids. It focuses on basic and practical information about working safely with these substances. Additional references are provided and it is strongly recommended that these and others be consulted prior to working with cresylic acids. Please do not hesitate to contact your regional Sasol office if we can be of assistance in the safe storage, handling, processing and disposal of our products.

Hazards

Health Hazards

The primary dangers posed in handling cresylic acids are those resulting from physical exposure. Cresylic acids are highly corrosive and contact with exposed skin or mucous membranes causes severe burns. These burns progress from an initial whitening of the exposed skin to blackishbrown necroses within 24 hours after exposure. Cresylic acids also exhibit anesthetic properties. Therefore, victims frequently misjudge the extent of their exposure when the initial burning sensation rapidly subsides. This can result in prolonged contact, causing toxic effects in addition to the corrosive damage. 

Cresylic acids are readily absorbed through the skin and mucous membranes in liquid or vapor form and act as systemic toxins for which there is no established treatment. Relatively small areas of exposure (e.g. an arm or a hand) can allow sufficient absorption to cause severe poisoning. Progressive symptoms of such poisoning include headache, dizziness, ringing in the ears, nausea, vomiting, muscular twitching, mental confusion, loss of consciousness and, possibly, death from lethal paralysis of the central nervous system. Chronic exposure can lead to loss of appetite, vomiting, nervous disorders, headaches, dizziness, fainting and dermatitis. 

The Occupational Health & Safety Administration (OSHA) has established 5ppm or 22 mg/m3 permissible exposure limits (PEL’s) for cresols on an 8-hour time-weighted average basis. OSHA guidelines also indicate that adequate personal protective equipment (PPE) should be employed to avoid skin contact with cresols. Cresylic acids are not listed as carcinogens by OSHA, the International Agency for Research on Cancer (IARC) or the National Toxicology Program (NTP).

Environmental Hazards

Cresylic acids show high acute toxicity towards both fish and aquatic invertebrates and must be prevented from entering surface or ground waters. Depending upon the specific composition, the material may be classified as a marine pollutant. Please refer to the current label and safety datasheet.

Controls for Working with Cresols

Safe storage, handling, processing and disposal of cresylic acids begin long before they ever arrive on-site. Measures necessary to ensure the health and well-being of employees, customers, the community and the  environment include the development of effective administrative and engineering controls designed to specifically address the hazards associated with cresylic acids. Personal protective equipment (PPE) is integral to safe handling and should be viewed as the last line of defense against an accidental failure of the administrative and/or engineering controls. 

Administrative Controls

Administrative controls are the foundation of any program designed for safely handling cresylic acids. Every company is unique in how they run their business and establish administrative controls. Those specifically developed for working with cresylic acids should address comprehensive process planning, thorough communication of hazards to employees and extensive training of employees on the proper implementation of all safety measures.

Personal Protective Equipment (PPE)

All personnel who work with or near cresylic acids must use adequate personal protective equipment (PPE). The extent of the potential exposure and consideration of established permissible exposure limits (PEL’s) should dictate the level of protection necessary. Personnel working with or near lab-scale quantities should always wear safety glasses with side-shields or

chemical mono-goggles, chemical-resistant or impermeable gloves, long-sleeved shirts and trousers as a minimum.

Circumstances such as elevated temperature and pressure or vacuum conditions should dictate if more substantial protection is necessary, including face shields, chemically impermeable outerwear, and breathing protection. Personnel transferring larger quantities of cresylic acids, or working in areas where a line-break could result in similar exposure, should always wear full protective equipment.

Emergency Procedures

Physical Exposure – External

The primary dangers involved in working with cresylic acids are the corrosive and toxic effects resulting from a physical exposure. Studies suggest that the severity of the exposure depends more on the magnitude of the exposed skin area than the concentration of cresylic acid. Therefore, the critical factor in dealing with an external physical exposure to cresylic acids is to minimize the extent and duration of the contact. To this end, the immediate response must be thorough flushing of the exposed areas with copious amounts of running water to remove all the cresylic acid in contact with the skin or eyes. Any contaminated clothing should be removed as quickly and carefully as possible during this process to avoid any additional skin contact.

Any exposed areas will have readily absorbed the cresylic acids and may be evidenced by a characteristic whitening of the skin. After thorough flushing with water, a solution consisting of 2 parts polyethylene glycol 400 to 1 part ethanol (PEG/EtOH) should be liberally applied to any affected skin (avoid contact with eyes), allowed to remain 15 to 30 seconds and then flushed away with fresh running water. Continue the cycling of PEG/EtOH and water for at least 15 minutes and then finish with thorough washing with soap and water. This decontamination procedure reduces the severity of the exposure, but does not completely eliminate damage to the skin or toxic effects. Medical attention should be sought as soon as possible.

Spill Containment & Clean-Up

Spill containment and cleanup of cresylic acids should only be performed by properly trained personnel employing an appropriate level of protective equipment as dictated by the extent of the spill. Small to medium spills on land should be surrounded by and absorbed onto inert clay absorbent and transferred to a disposal container. Larger land-spills should be diverted away from waterways, contained with booms, dikes or trenches, and collected in a vacuum truck. Any residual cresylic acids remaining after vacuuming should be cleaned up using the clay absorbent. All soils affected by the spill should be removed and placed in approved disposal containers.

Water spills are of particular concern due to the acute toxicity of cresylic acids to marine life. Clean up efforts should focus on containing the spill and quickly removing the cresylic acids that settle in deeper areas of the waterway. This can be aided greatly if the flow of water can be slowed or stopped. Further efforts should focus on removing as much of the dissolved cresylic acids as possible from the water using activated charcoal.

The composition and extent of any spill should be evaluated against local guidelines (ex. SARA Title III and RCRA in the U.S.) and reported to the proper agencies, if necessary. Any non disposable clean-up equipment should be thoroughly decontaminated with soap and water after use.

Source : SASOL / USA

Safe Handling of Cresols, Xylenols & Cresylic Acids

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Some significant points to note about Cresylic Acid

Below is a photo taken 10 years ago in the Irish Army Air Corps NDT shop,  part of the Avionics / ERF building complex. Ardrox 666 can be seen spilled on the ground where it was free to leach through a shore onto the grass verge outside. 

  • 25% of fresh Ardrox 666 used by the Air Corps was Cresylic Acid. This percentage was higher in waste Ardrox 666 as Dichloromethane evaporated.
  • That greenish / yellow stain dripping from the extractor fan is also Ardrox 666 from the air.

DELAY – DENY – DIE

What are Isocyanates?

What are Isocyanates?

An isocyanate is any chemical that contains at least one isocyanate group in its structure. An isocyanate group is a group of atoms containing one nitrogen atom attached by a double covalent bond to one carbon atom, which in turn is attached by a second double bond to an oxygen atom (indicated in structure as -N=C=O). (Do not confuse this with the cyanate functional group which is arranged as –O–C≡N). A chemical containing two such isocyanate groups is called a diisocyanate. Common examples are toluene diisocyanate (TDI), hexamethylene diisocyanate (HDI) and methylene diphenylmethane diisocyanate (MDI).

Isocyanates (a description which includes diisocyanates) are the raw materials that make up all polyurethane products. Isocyanates react with compounds containing alcohols to produce polyurethane polymers – which are used in polyurethane foams, thermoplastic elastomers and “2 pack” type polyurethane paints to improve the performance, durability and finish of painted surfaces. Jobs that may involve exposure to isocyanates include painting with polyurethane products, foam-blowing and the manufacture of polyurethane products like insulation materials, surface coatings, furniture, foam mattresses, under-carpet padding, packaging materials, laminated fabrics, polyurethane rubber, adhesives and also exposure can occur during the thermal degradation of polyurethane products.

Health Effects

Exposure to hazardous materials may be acute or chronic. Acute exposures refer to single high concentration exposures over shorter periods, while chronic exposures are repeated or continuous exposures over longer periods. Exposures to any toxic material may have either acute, immediate effects and/or chronic, long term health effects.

Inhalation:

Isocyanates are known to have a strong effect on the respiratory tract in some people. It is reported that there is a susceptible group in the population (estimated to be 5-20% of workers who are exposed occupationally) who can become sensitised to Isocyanates. Sensitization is the body’s hyper-reactive (allergy-like) response to a substance which has been touched or inhaled by a susceptible individual. Sensitization may develop as a result of a large single overexposure, for example, from a spill or accident, or from repeated overexposure at lower levels.

Once sensitised, these people, when later exposed to even very low concentrations of isocyanates even at levels below the exposure standard, can react by developing asthma-like symptoms, such as chest tightness, cough, wheezing and shortness of breath. Such attacks may occur up to several hours after cessation of exposure (for example, during the night after exposure) but, if a person is particularly sensitive, the attack can occur earlier or immediately. This sensitisation is essentially irreversible and can prevent any further work for the individual in their job using Isocyanates or any position associated with use of Isocyanates – even at very low levels below the regulated exposure level and that may not affect others. Many spray painters working in smash repair shops have had to leave the industry because they are sensitised to isocyanates.

An individual’s response to isocyanate exposure can be immediate or may be delayed for several years. Asthmatic people are more prone to sensitisation and other adverse reactions. Persons with a history of asthma, allergies, hay fever, recurrent acute bronchitis or any occupational chest disease or impaired lung function is advised against risking exposure to isocyanates. In rare cases, death has occurred from a severe asthma attack after significant isocyanate exposure.

Skin

Isocyanates are also skin irritants (causing inflammation and dermatitis) and there is some evidence that skin exposure can also cause respiratory sensitisation.

Eyes

Isocyanates are an irritant to the eyes. Splashes can cause severe chemical conjunctivitis.

Other Health Effects

Other health effects which have been reported include liver and kidney dysfunction. Some Isocyanate materials are considered to be potential human carcinogens (IARC).

Spraying Isocyanate Paints

Spray painters need to understand the health risks involved in spraying polyurethane paints – these are the two-pack mixes of polyurethane paints and possibly also in the one-pack moisture-cured mixes. These products are widely used in the automotive and other industries because of their excellent gloss, hardness, adhesion and chemical resistance.

The major hazard with spraying polyurethane paints is breathing the mist or aerosol droplets of the paint spray and absorbing the isocyanate and other components into your lungs.

The odour threshold for isocyanates, i.e. the level at which an individual can smell an isocyanate, is typically higher than the allowed exposure limits. In other words, if a painter smells the sweet, fruity, pungent odour of an isocyanate, they are probably already overexposed. That is why the recommended respiratory protection for employees spraying isocyanates is a supplied air respirator and not an air purifying respirator (i.e. filter cartridge style). The issue with use of air purifying respirators is that they will reach a point at which the filter becomes saturated and will no longer capture the isocyanate or other solvents. When that filter breakthrough happens, an Isocyanates overexposure can occur, potentially causing an irreversible sensitization. Use of a supplied air system removes this filter change factor – it does not rely on the painter changing his gas/vapour filters at appropriate intervals.

Note: if isocyanate-containing paint is applied by brush, roller or dipping, in a well ventilated area, there is generally no more hazard than with ordinary paints. These application methods usually do not produce the higher concentrations of isocyanate vapour associated with spraying.

After curing, polyurethane paints contain no free isocyanates and are not hazardous under normal use. However, welding or burning of polyurethane coated surfaces can release a range of contaminants. Gases or vapours evolved can include HDI, TDI, MDI as well as many other compounds (metal fumes, organic gases or vapours, particulates), depending on the original polyisocyanate resin used. When welding or cutting metal coated with a polyurethane coating, a worker may be exposed to a range of these decomposition products which will vary depending on type of process being used to weld or cut, the nature of the base metal and type of coating. Respiratory protection that is suitable for welding applications will also provide suitable respiratory protection in these cases

Source 3M Australia / New Zealand

http://multimedia.3m.com/mws/media/777847O/isocyanates-3m-techupdate.pdf

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Some significant points to note from this 3M document.

  1. Exposure can occur when cured isocyanates are heated.
  2. An individual’s response to isocyanate exposure can be immediate or may be DELAYED FOR SEVERAL YEARS.
  3. Skin exposure can also cause respiratory sensitisation.
  4. The odour threshold for isocyanates, i.e. the level at which an individual can smell an isocyanate, is typically higher than the allowed exposure limits.
  5. The Air Corps did eventually provide a “supplied air” respirator to spray paint & welding personnel. Unfortunately they sourced the “supplied air” from an old machine compressor located in ERF where the air had previously tested as 3.5 times over the allowed limit for Dichloromethane i.e. allowed limit was 50ppm and sourced air was from a location measured at 175ppm…out of the frying pan and into the fire.

Air Corps Isocyanate Usage

Isocyanates were used by the Spray Paint Shop (Dope Shop) at Baldonnel. For most of the existence of this shop personnel were NOT supplied with ANY PPE. The walls between the Spray Paint Shop and Engineering Wing Hangar & Workshops were not sealed and so isocyanates and other chemicals entered these workplaces whilst spraying was in progress exposing all personnel.

Furthermore if a component could not be removed from an aircraft for spray painting it was spray painted in-situ in Engineering Wing Hangar whilst unprotected line & tech personnel worked in adjoining offices & workshops or on other aircraft in the hangar.

A “waterfall” system with an extractor fan was also present. Personnel spray painted aircraft components toward the waterfall which captured most of the over-spray droplets. Fumes from this waterfall were then extracted by a fan, up a duct and released at approximately 3m height where the prevailing winds then carried the extracted fumes in the doors & windows of Avionics Squadron & Engine Repair Flight exposing further unprotected personnel.

Sensitisation is irreversible and once sensitised it is next to impossible to avoid isocyanates in the modern environment. It is also likely that health effects are suffered beyond the respiratory system & skin for example the gastric & nervous systems. 

DELAY – DENY – DIE

Individual chemical constituents of Aviation Gasoline (AVGAS) & Jet Fuel (AVTUR)

We have just added links to Safety Data Sheets which show the constituent chemicals for AVGAS (100LL) as well as AVTUR (Jet A-1) on our Chemical Product Names & Safety Data Sheets page.

AVGAS - 100LL

Chemical NameCAS-NoClassification
Gasoline86290-81-5 Muta. 1B
Carc. 1B
Asp. Tox. 1
Tetraethyl lead 78-00-2 Acute Tox. 1
Repr. 1A
STOT RE 2
Toluene108-88-3Skin Irrit. 2
Repr. 2
STOT Single Exp. 3
STOT Rep. Exp. 2
Asp. Tox. 1
Xylene, mixed isomers1330-20-7
Acute Tox. 4 - Dermal
Acute Tox. 4 - Inhalation
Skin Irrit. 2
Ethylbenzene100-41-4Acute Tox. 4 - Inhalation
STOT Rep. Exp. 2
Asp. Tox. 1
Cyclohexane110-82-7
Skin Irrit. 2
STOT Single Exp. 3
Asp. Tox. 1
n-Hexane110-54-3Skin Irrit. 2
Repr. 2
STOT Single Exp. 3
STOT Rep. Exp. 2
Asp. Tox. 1
Trimethylbenzene, all
isomers 		Trimethylbenzene, all
isomers 		Skin Irrit. 2
Eye Irrit. 2B
STOT Single Exp. 3
STOT Rep. Exp. 1
Asp. Tox. 1
Naphthalene91-20-3
Acute Tox. 4 - Oral
Carc. 2
Cumene (Isopropylbenzene)98-82-8STOT Single Exp. 3
Asp. Tox. 1
 

AVTUR - Jet A1

Chemical NameCAS-NoClassification
Kerosine (petroleum) 8008-20-6 Asp. Tox.1
Skin Irrit.2
STOT RE3
Kerosine (petroleum),
hydrodesulfurized 		64742-81-0
Asp. Tox.1
Skin Irrit.2
STOT RE3
Kerosene (Fischer
Tropsch), Full range,
C8-C16 branched and
linear		848301-66-6 Asp. Tox.1
Ethylbenzene100-41-4Acute Tox. 4 - Inhalation
STOT Rep. Exp. 2
Asp. Tox. 1
Xylene, mixed isomers1330-20-7

Acute Tox. 4 - Dermal
Acute Tox. 4 - Inhalation
Skin Irrit. 2
Cumene (Isopropylbenzene)98-82-8STOT Single Exp. 3
Asp. Tox. 1
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On the 26th of January 2016 the current head of Health & Safety in the Irish Army Air Corps stated in an email to the Medical Corps that “The Formation Safety & Unit Safety Personnel have reviewed refuelling work practices and believe that the risk of exposure is low.”

Profile of Patients with Chemical Injury & Sensitivity

Patients reporting sensitivity to multiple chemicals at levels usually tolerated by the healthy population were administered standardised questionnaires to evaluate their symptoms and the exposures that aggravated these symptoms. Many patients were referred for medical tests. It is thought that patients with chemical sensitivity have organ abnormalities involving the liver, nervous system (brain, including limbic, peripheral, autonomic), immune system, and porphyrin metabolism, probably reflecting chemical injury to these systems. Laboratory results are not consistent with a psychological origin of chemical sensitivity.

Substantial overlap between chemical sensitivity, fibromyalgia, and chronic fatigue syndrome exists: the latter two conditions often involve chemical sensitivity and may even be the same disorder. Other disorders commonly seen in chemical sensitivity patients include headache (often migraine), chronic fatigue, musculoskeletal aching, chronic respiratory inflammation (rhinitis, sinusitis, laryngitis, asthma), attention deficit, and hyperactivity (affected younger children). Less common disorders include tremor, seizures, and mitral valve prolapse. Patients with these overlapping disorders should be evaluated for chemical sensitivity and excluded from control groups in future research.

Agents whose exposures are associated with symptoms and suspected of causing onset of chemical sensitivity with chronic illness include gasoline, kerosene, natural gas, pesticides (especially chlordane and chlorpyrifos), solvents, new carpet and other renovation materials, adhesives/glues, fiberglass, carbonless copy paper, fabric softener, formaldehyde and glutaraldehyde, carpet shampoos (lauryl sulfate) and other cleaning agents, isocyanates, combustion products (poorly vented gas heaters, overheated batteries), and medications (dinitrochlorobenzene for warts, intranasally packed neosynephrine, prolonged antibiotics, and general anesthesia with petrochemicals).

Multiple mechanisms of chemical injury that magnify response to exposures in chemically sensitive patients can include neurogenic inflammation (respiratory, gastrointestinal, genitourinary), kindling and time-dependent sensitisation (neurologic), impaired porphyrin metabolism (multiple organs), and immune activation

Please read full report below.

Grace Ziem – Occupational and Environmental Medicine, Baltimore, Maryland, USA. James McTamney – Clinical Psychologist, Lutherville, Maryland, USA