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, Carbon Disulfide


Related Terms

  • Carbon Bisulfide Poisoning
  • Carbon Disulfide Poisoning
  • Carbon Sulfide Poisoning
  • Dithiocarbonic Anhydride Poisoning
  • Sulphocarbonic Anhydride Poisoning
  • Weeviltox Poisoning

Differential Diagnosis

Specialists

  • Medical Toxicologist
  • Neurologist
  • Pharmacologist
  • Preventive Medicine Specialist

Comorbid Conditions

  • Pre-existing disease in same affected organ system

Factors Influencing Duration

The level and length of time exposed, route of exposure (skin contact, inhalation, and ingestion), individual's response to exposure, immediacy of treatment, and response to treatment may influence the length of disability. Age, pre-existing disease, and mental attitude have an effect on the individual's ability to return to pre-injury functional status.

Medical Codes

ICD-9-CM:
982.2 - Toxic Effect of Solvents Other than Petroleum Based, Carbon Disulfide; Carbon Bisulfide

Overview

Pure carbon disulfide is a highly flammable, colorless liquid with a pleasant odor. The impure carbon disulfide used in most industrial processes is a yellowish liquid with an unpleasant odor. Carbon disulfide has been an important industrial chemical since the 1800s with many useful properties including the ability to solubilize fats, rubbers, phosphorus, sulfur, and other elements. Carbon disulfide's most important industrial use is in the manufacture of regenerated cellulose rayon (using the viscose process) and cellophane. Another principal industrial use is as a feedstock for carbon tetrachloride production. Carbon disulfide is also used to protect fresh fruit from insects and fungus during shipping, in adhesives for food packaging, and for solvent extraction of growth inhibitors. It is a common fumigant used in grain elevators and silos.

Carbon disulfide readily evaporates when exposed to air and can be absorbed into the body. Inhalation is the most common route of exposure, but carbon disulfide can also be absorbed through the skin. Individuals most often exposed to carbon disulfide are workers in plants that use carbon disulfide in the manufacturing processes, particularly in plants that manufacture rayon. Grain workers, farmers, and grain inspectors are also at increased risk.

Prolonged exposure of female workers to low concentrations of carbon disulfide is associated with birth defects in their children. Exposure limit values provide little margin of safety for risk of developmental effects.

Source: Medical Disability Advisor



Diagnosis

History: An individual who has inhaled carbon disulfide may complain of irritation to the nose, eyes, throat, and lungs. Common symptoms include runny nose, sore throat, burning eyes, and difficulty breathing. Carbon disulfide that comes into contact with the skin can cause irritations and burns.

Other reported effects of exposure include multiple ocular effects and GI disturbances.

Physical exam: Physical findings depend on the extent of the exposure. High concentration exposures may produce encephalopathy with headache, dizziness, fatigue, decreased mental processing speed, hallucinations, delusions, or psychosis. There may be alterations in reflexes, involuntary movements of the eyes (nystagmus), and impaired ability to coordinate movements such as difficulty walking (ataxia). Chronic, low level exposures damage peripheral nerves with decreases in sensation and strength. Chronic exposure is also associated with decreased sperm production in males, menstrual irregularities in females, and increased risk of heart disease.

Tests: Blood and urine tests assess the presence of carbon disulfide; generally these tests aren't that useful because they cannot determine the degree of exposure. If there has been severe exposure to carbon disulfide, certain breathing tests can be used to determine if the lungs have been affected, and eye tests to determine ocular damage. Electrodiagnostic tests can be helpful in identifying early neurologic changes related to chronic carbon disulfide exposure.

Source: Medical Disability Advisor



Treatment

The first step in therapy is to remove the individual from further exposure. Treatment after this depends on the extent of exposure and the organ system affected.

If carbon disulfide exposure is by inhalation, the individual should be moved to fresh air and given artificial respiration, as indicated. Inhalation therapy may be necessary. Following skin contact, the skin should be rinsed with plenty of water, contaminated clothing removed, and the skin rinsed again. Eyes should be liberally flushed with water for several minutes. Contact lenses should be removed if possible.

There is no antidote for carbon disulfide poisoning. Treatment is typically dependent on an individual's symptoms. Individuals with severe exposure may need to be hospitalized. Antidepressants may be prescribed for alterations in mood or symptoms associated with peripheral neuropathy.

Source: Medical Disability Advisor



Prognosis

Prognosis is dependent on the extent and duration of exposure. An individual who has experienced a single exposure and recovered quickly is not likely to have any long-term effects. Death can occur if an individual is acutely exposed to extremely high levels of carbon disulfide.

Source: Medical Disability Advisor



Rehabilitation

Any toxic condition caused by carbon disulfide may warrant rehabilitation if the condition results in respiratory, cardiovascular, and central nervous system disorders. Once initial symptoms are stabilized and a physician determines no contraindications to physical activity, a gradual strengthening program is initiated by the rehabilitation professional. If necessary, respiratory exercises are instructed to improve ventilation of individuals with breathing difficulties.

Muscles that aid in breathing are strengthened using specific postures and positions of the secondary respiratory muscles.

Because carbon disulfide can cause atherosclerosis, individuals rehabilitating from this toxic condition progress to strengthening and endurance exercises through aerobic activities. As endurance increases the individual performs active upper and lower extremity exercises beginning with very light resistance and then progressing to moderate resistance. If exercises are tolerated well, isotonic exercises are added to the regime to build strength. The goal of the individual will dictate the number of appropriate sets and repetitions.

If necessary, the rehabilitation program should include exercises that address any losses of balance and coordination the toxicity may have had on the nervous system.

Frequency of the program may vary somewhat depending on the individual's general health. If tolerated, strengthening exercises are performed 3 times per week, with aerobic activities on the nonstrengthening days of the program.

Occupational therapy may also be needed to recover and develop job-related skills. If toxic effects on the central nervous system have caused problems with dexterity, exercises that require skills of the fingers and hand are done to gain better skill and hand/eye coordination.

The rehabilitation program varies for individuals affected by the toxic effects of carbon disulfide. Modifications may be needed for those individuals on various medications or who experience other symptoms from the condition. The intensity and progression of exercises depend on the affected body organs (specifically the respiratory system) and the individual's overall health. Job retraining may be needed through vocational therapy and education if heart disease has compromised the individual's ability to perform normal job responsibilities.

Source: Medical Disability Advisor



Complications

Overexposure to carbon disulfide is associated with an increase in coronary heart disease, renal damage, hypertension, and high frequency hearing loss. Acute carbon disulfide toxicity can damage cranial nerves, cause peripheral neuropathy with paresthesias and muscle weakness, and cause unsteady gait and dysphagia. There may be permanent axonal neuropathy. In extreme cases of acute intoxication, a parkinsonian-like syndrome may occur characterized by speech disturbances, muscle spasticity, tremor, memory loss, and depression.

Source: Medical Disability Advisor



Ability to Work (Return to Work Considerations)

Changing an individual's exposure time to carbon disulfide may need to be considered (shift change or new job responsibilities, available breathing masks and latex gloves).

The Occupational Safety and Health Administration's (OSHA) established airborne permissible exposure limit (PEL) is 20 parts per million (ppm) of carbon disulfide averaged over an 8-hour work shift. OSHA has also set 30 ppm as an acceptable ceiling; and 100 ppm of carbon disulfide as a maximum peak above the acceptable ceiling concentration, not to be exceeded during any 8-hour work period (Rutchik).

The National Institute of Occupational Safety and Health's (NIOSH) recommended exposure limit is 1 ppm averaged over a 10-hour work shift and 10 ppm of carbon disulfide not to be exceeded during any 15-minute work period (Rutchik).

The American Conference of Governmental Industrial Hygienists' (ACGIH) recommended airborne exposure limit is 10 ppm of carbon disulfide averaged over an 8-hour work shift (Rutchik).

Individuals who have been exposed should avoid alcohol for at least 24 hours and exposure to cigarette smoke for 72 hours. Vigorous physical activity should be avoided for 1 to 2 days post exposure.

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 exposure to carbon disulfide been confirmed?
  • Is the exposure dose within the range of doses believed to cause such effects?
  • Is the timing between exposure and clinical onset compatible with the known biologic facts about the hazard?
  • Is the clinical illness including history, physical examination, and laboratory findings consistent with other case descriptions?
  • Are there special attributes of the particular individual that make it more or less likely that he or she would be so affected?

Regarding treatment:

  • Was treatment timely and appropriate for the type of exposure individual experienced?
  • Has individual been hospitalized?
  • Were antidepressants prescribed for mood alterations or symptoms associated with peripheral neuropathy?
  • Was individual instructed to refrain from alcohol for 24 hours and exposure to cigarette smoke for 72 hours?

Regarding prognosis:

  • Is there a history of carbon disulfide exposure in the workplace?
  • Has individual recently worked in another organization where carbon disulfide exposure is higher?
  • Where there remains significant uncertainty about the cause, how important is it to be certain?

Source: Medical Disability Advisor



References

Cited

Rutchik, Jonathan S. "Organic Solvents." eMedicine. Eds. Roberta J. Seidman, et al. 18 Jan. 2002. Medscape. 27 Oct. 2004 <http://emedicine.com/neuro/topic285.htm#section~treatment>.

Source: Medical Disability Advisor






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