Sedentary Work Exerting up to 10 pounds (4.5 kg) of force occasionally and/or a negligible amount of force frequently or constantly to lift, carry, push, pull, or otherwise move objects, including the human body. Sedentary work involves sitting most of the time, but may involve walking or standing for brief periods of time. Jobs are sedentary if walking and standing are required only occasionally and other sedentary criteria are met.

Light Work Exerting up to 20 pounds (9.1 kg) of force occasionally and/or up to 10 pounds (4.5 kg) of force frequently, and/or negligible amount of force constantly to move objects. Physical demand requirements are in excess of those for Sedentary Work. Light Work usually requires walking or standing to a significant degree. However, if the use of the arm and/or leg controls requires exertion of forces greater than that for Sedentary Work and the worker sits most the time, the job is rated Light Work.

Medium Work Exerting up to 50 (22.7 kg) pounds of force occasionally, and/or up to 25 pounds (11.3 kg) of force frequently, and/or up to 10 pounds (4.5 kg) of forces constantly to move objects.

Heavy Work Exerting up to 100 pounds (45.4 kg) of force occasionally, and/or up to 50 pounds (22.7 kg) of force frequently, and/or in excess of 20 pounds (9.1 kg) of force constantly to move objects.

Very Heavy Work Exerting in excess of 100 pounds (45.4 kg) of force occasionally, and/or in excess of 50 pounds (22.7 kg) of force frequently, and/or in excess of 20 pounds (9.1 kg) of force constantly to move objects.

Job Classification

In most duration tables, five job classifications are displayed. These job classifications are based on the amount of physical effort required to perform the work. The classifications correspond to the Strength Factor classifications described in the United States Department of Labor's Dictionary of Occupational Titles. The following definitions are quoted directly from that publication.

Sedentary Work Exerting up to 10 pounds (4.5 kg) of force occasionally and/or a negligible amount of force frequently or constantly to lift, carry, push, pull, or otherwise move objects, including the human body. Sedentary work involves sitting most of the time, but may involve walking or standing for brief periods of time. Jobs are sedentary if walking and standing are required only occasionally and other sedentary criteria are met.

Light Work Exerting up to 20 pounds (9.1 kg) of force occasionally and/or up to 10 pounds (4.5 kg) of force frequently, and/or negligible amount of force constantly to move objects. Physical demand requirements are in excess of those for Sedentary Work. Light Work usually requires walking or standing to a significant degree. However, if the use of the arm and/or leg controls requires exertion of forces greater than that for Sedentary Work and the worker sits most the time, the job is rated Light Work.

Medium Work Exerting up to 50 (22.7 kg) pounds of force occasionally, and/or up to 25 pounds (11.3 kg) of force frequently, and/or up to 10 pounds (4.5 kg) of forces constantly to move objects.

Heavy Work Exerting up to 100 pounds (45.4 kg) of force occasionally, and/or up to 50 pounds (22.7 kg) of force frequently, and/or in excess of 20 pounds (9.1 kg) of force constantly to move objects.

Very Heavy Work Exerting in excess of 100 pounds (45.4 kg) of force occasionally, and/or in excess of 50 pounds (22.7 kg) of force frequently, and/or in excess of 20 pounds (9.1 kg) of force constantly to move objects.

Toxic Effects, Hydrochloric Acid


Related Terms

  • Chlorhydric Acid Poisoning
  • Hydrochloride Poisoning
  • Hydrogen Chloride Poisoning
  • Muriatic Acid Poisoning
  • Spirits of Salts Poisoning

Differential Diagnosis

  • Caustic ingestion toxicity
  • Electrical injuries
  • Ocular burns
  • Thermal burns

Specialists

  • Critical Care Surgeon
  • Gastroenterologist
  • General Surgeon
  • Medical Toxicologist
  • Ophthalmologist
  • Otolaryngologist
  • Pharmacologist
  • Preventive Medicine Specialist
  • Psychiatrist

Factors Influencing Duration

Absorbed dose is the primary determinant of the severity of toxic effects and therefore the severity and duration of disability. Absorbed dose depends on environmental levels, routes of exposure (skin contact, inhalation, ingestion), and the duration of exposure.

Age, general physical condition, and pre-existing disease will also influence the duration of disability and the individual's recovery to pre-injury functional capacity and return to work.

Medical Codes

ICD-9-CM:
983.1 - Toxic Effect of Corrosive Aromatics, Acids, and Caustic Alkalis, Hydrofluoric Acid; Nitric Acid; Sulfuric Acid

Overview

Hydrochloric acid, or muriatic acid, is the aqueous solution of hydrogen chloride (HCl). Hydrogen chloride is a colorless to slightly yellowish gas that can be shipped as a liquefied compressed gas. Both have a sharp, irritating odor. Hydrogen chloride is used in the production of chlorinated organic chemicals and dyes and intermediates, in steel pickling, in various mining and oil drilling operations, and as a cleaning and sterilizing agent. It is used in the photographic, textile, brewing, food-processing, and rubber industries. Exposure may occur by inhalation, ingestion, or eye or skin contact.

Skin contact causes burns, dermatitis, and ulcers of the skin. Corneal burns from exposure can lead to partial or complete loss of vision. The mouth, esophagus, and stomach can be burned after swallowing HCl.

The threshold for tolerably safe exposure is 10 parts per million (ppm); even brief exposure to 35 ppm can irritate the throat. Individuals cannot stand being exposed to concentrations in the range of 50 to 100 ppm, and exposure to 1,300 to 2,000 ppm of HCl is fatal.

Incidence and Prevalence: In 2002, 3,452 individuals were exposed to hydrochloric acid, according to the American Association of Poison Control Centers Surveillance System; 22 people had a severe reaction, with life-endangering medical complications that resulted in disability, and 2 died from exposure (Watson).

Source: Medical Disability Advisor



Diagnosis

History: Individuals with early exposure can present with irritation of the nasopharynx, burns on the skin and eyes, and blindness; chronic exposure causes tooth discoloration, dermatitis, and sensitivity to light. Individuals who ingest the substance have coughing, vomiting, chest pain, shortness of breath, and burns of the esophagus and stomach.

Physical exam: Examination of the eye should include visual acuity, corneal staining with fluorescein to identify corneal epithelium injury, and identification of burns around the eyes.

The entirety of the skin surface should be examined to locate any burned areas. Any clothing or other material should be removed to stop further injury.

Any sign of difficulty maintaining an airway should be immediately addressed.

An abdominal examination should be performed to look for evidence of tenderness or discomfort. Oral and gastrointestinal burns should also be identified.

Tests: Views of the oropharynx, esophagus, and stomach should be taken to determine the extent of damage. The esophagus and stomach should not be ignored, even if no intra-oral lesions are found, because up to 30% of individuals without signs of oral lesions have significant damage further down the gastrointestinal tract (Cox). If the patient swallowed HCl, abdominal and chest x-rays and endoscopy are indicated.

Source: Medical Disability Advisor



Treatment

Treatment involves removal from exposure, decontamination and supportive care. Prior to transport to a hospital emergency room following inhalation of hydrogen chloride gas, the individual must be removed from further exposure and placed in fresh air. Cardiopulmonary resuscitation or rescue breathing (CPR) must be performed, if needed. In the event of skin contact, the contaminated clothes must immediately be removed and the skin washed with flowing water for at least 15 minutes. In cases of ingestion, vomiting must not be induced. Instead, the individual should be given large amounts of water or milk. Eyes exposed to hydrochloric acid must be washed immediately with large amounts of water for at least 15 minutes while the upper and lower lids are held open. The eyes should continue being irrigated with normal saline.

Source: Medical Disability Advisor



Prognosis

Prognosis is dependent on the extent and duration of exposure.

Source: Medical Disability Advisor



Rehabilitation

Rehabilitation varies for individuals affected by the toxic effects of hydrochloric acid. The intensity and progression of exercises depends on the body organs affected (specifically, the respiratory system) and the individual's overall health.

Any toxic condition caused by hydrochloric acid may warrant rehabilitation if the condition results in general weakness and/or affects the respiratory system. Once initial symptoms are stabilized and a physician determines no contraindications to physical activity, the rehabilitation professional initiates a gradual strengthening program.

If necessary, the therapist may instruct the individual with breathing difficulties in respiratory exercises to improve ventilation. A speech therapist trained in swallowing evaluations becomes involved in the rehabilitation program if the condition results in dysphagia or speech impairment. If there is impaired or permanent loss of vision from this condition, occupational therapy may help the individual adapt to his or her surroundings and assist in retraining for activities of daily living (e.g., dressing or grooming).

Once breathing and/or swallowing returns to normal, individuals then progress to strengthening and endurance exercises. Aerobic-type activities help individuals increase their ability to work and their resistance to fatigue. The frequency of the program may vary somewhat, depending on the individual's general health.

Muscle weakness is addressed with strengthening exercises and education regarding the importance of remaining as active as possible. If necessary, the rehabilitation program needs to address any neurological complications, such as loss of balance and coordination. As the individual progresses, the difficulty of balance and coordination exercises can increase.

Source: Medical Disability Advisor



Complications

The teeth may become eroded and change colors. Burned skin may develop scars, and eye burns may cause permanent blindness and cataracts. Infection may occur in areas where skin has been lost. Ingestion may lead to esophageal strictures.

Source: Medical Disability Advisor



Ability to Work (Return to Work Considerations)

The Occupational Safety and Health Administration's (OSHA) and the National Institute of Occupational Safety and Health's (NIOSH) airborne ceiling exposure limit is 5 parts per million (ppm), which must not be exceeded. The individual must have access to information about the health effects of hydrochloric acid exposure in the workplace. Respirators, air filters, protective clothing, and eyewear may be required. The length and levels of hydrochloric acid exposure in the workplace must be stringently monitored. The individual required to handle the chemical may need special training.

Source: Medical Disability Advisor



Failure to Recover

If an individual fails to recover within the expected maximum duration period, the reader may wish to consider the following questions to better understand the specifics of an individual's medical case.

Regarding diagnosis:

  • Has diagnosis of toxic effects of hydrochloric acid been confirmed?
  • Is there a history of hydrochloric acid exposure in the workplace?
  • Is timing between exposure and clinical onset compatible with the known biologic facts about the hazard?
  • Is exposure dose within the range of doses believed to cause such effects?
  • Is clinical illness, including the history, physical examination, and laboratory findings, consistent with other case descriptions?
  • Has individual experienced any complications such as pulmonary edema, pneumonitis, perforation of the esophagus or stomach, or peritonitis?
  • Does individual have an underlying condition that may affect recovery?

Regarding treatment:

  • Was first aid administered? Did individual receive prompt and appropriate treatment?
  • Was individual transported to the emergency room? If treatment was delayed, did individual experience any complications?
  • Has individual stopped smoking?
  • Would individual benefit from enrollment in a smoking cessation program?

Regarding prognosis:

  • Did individual experience any residual impairment?
  • If present, how incapacitating are symptoms?
  • Has individual recently worked in another organization where hydrochloric acid exposure is higher?
  • Could hydrochloric acid exposure be occurring outside the workplace, such as the home, community, or recreational activities?
  • Are there special attributes of the particular individual that make it more or less likely that he or she would be so affected?
  • Are there additional lifestyle or behavioral factors that may potentially contribute to this condition?
  • Where there remains significant uncertainty about the cause, how important is it to be certain?

Source: Medical Disability Advisor



References

Cited

Cox, R., and John Brooks. "Burns, Chemical." eMedicine. Eds. Jerry Balentine, et al. 17 Nov. 2004. Medscape. 4 Jan. 2005 <http://emedicine.com/plastic/topic73.htm http://emedicine.com/emerg/topic73.htm>.

Watson, William A., et al. "2002 Annual Report of the American Association of Poison Control Centers Toxic Exposure Surveillance System." American Journal of Emergency Medicine 21 5 (2003): 353-421. MD Consult. Elsevier, Inc. 4 Jan. 2005 <http://home.mdconsult.com>.

Source: Medical Disability Advisor






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