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Arsenic is a naturally occurring element in the earth’s crust, such as in copper and lead ores, where it is usually found in compounds with oxygen, chlorine, and sulfur. These are called inorganic arsenic compounds. Arsenic in plants and animals combines with carbon and hydrogen. This is called organic arsenic. Organic arsenic is usually less harmful than inorganic arsenic. Pure arsenic is a gray-colored metal, but this form is not common in the environment. Most arsenic compounds have no smell or special taste.
The main use of arsenic is for pesticides. Some products, mostly weed killers, use arsenic as the active ingredient. Other pesticides use inorganic forms of arsenic to kill plants, insects, or rodents, or to preserve wood. Persons who manufacture or use these pesticides or handle treated wood may be exposed to arsenic if adequate safety procedures are not followed. Inorganic arsenic is regulated by OSHA at 29 CFR 1910.1018.
Some facts about arsenic include the following:
- It doesn’t evaporate.
- Most arsenic compounds can dissolve in water.
- It gets into air when contaminated materials are burned.
- It settles from the air to the ground.
- It doesn’t break down, but can change from one form to another.
- Fish and shellfish build up organic arsenic in their tissues, but most of the arsenic in fish isn’t toxic.
Exposure/Effects
You can be exposed to arsenic by breathing sawdust or burning smoke from wood containing arsenic, breathing workplace air, ingesting contaminated water, soil, or air at waste sites, or ingesting contaminated water, soil, or air near areas naturally high in arsenic
If you are exposed to arsenic, you may expect negative effects. Inorganic arsenic is a human poison. Organic arsenic is less harmful. High levels of inorganic arsenic in food or water can be fatal. A high level is 60 parts of arsenic per million parts of food or water (60 ppm). Arsenic damages many tissues including nerves, stomach and intestines, and skin. Breathing high levels can give you a sore throat and irritated lungs.
Lower levels of exposure to inorganic arsenic may cause:
- Nausea, vomiting, and diarrhea;
- Decreased production of red and white blood cells;
- Abnormal heart rhythm;
- Blood vessel damage; and
- A “pins and needles” sensation in hands and feet
The most characteristic effect of oral exposure to inorganic arsenic is a pattern of skin abnormalities, including the appearance of dark and light spots on the skin, and small corns on the palms, soles, and trunk, which may progress to skin cancer. Direct skin contact may cause redness and swelling. Arsenic ingestion has also been reported to increase the risk of cancer of the liver, bladder, kidney, and lung.
Long term exposure to inorganic arsenic may lead to a darkening of the skin and the appearance of small “corns” or “warts” on the palms, soles, and torso. The Department of Health and Human Services (DHHS) has determined that arsenic is a known carcinogen. Breathing inorganic arsenic increases the risk of lung cancer. Ingesting inorganic arsenic increases the risk of skin cancer and tumors of the bladder, kidney, liver, and lung.
There are medical tests to show whether you’ve been exposed to arsenic. These tests can measure your exposure to high levels of arsenic. These tests, however, are not routinely performed in a doctor’s office.
Arsenic can be measured in your urine. This is the most reliable test for arsenic exposure. Since arsenic stays in the body only short time, you must have the test soon after exposure.
Tests on hair or fingernails can measure your exposure to high levels of arsenic over the past 6-12 months. These tests are not very useful for low level exposures.
These tests do not predict whether you will have any harmful health effects.
Protection
OSHA considers this chemical to be a toxic and hazardous substance, and has promulgated regulations that limit employee exposure. According to their regulation (29 CFR 1910.1018), the maximum permissible exposure limit for workplace airborne arsenic is 10 micrograms per cubic meter (µg/m³).
To comply with 29 CFR 1910.1018, administrative or engineering controls must first be determined and implemented whenever feasible. When these controls are not feasible to achieve full compliance, protective equipment or any other protective measures must be used to keep the exposure of employees to air contaminants within the limits prescribed in the regulation. Any equipment and/or technical measures used for this purpose must be approved for each particular use by a competent industrial hygienist or other technically qualified person.
Employees who have contact with this chemical must understand the hazards and the methods of control associated with these hazards.
Training
The employer must institute a training program for all employees who (1) are subject to exposure to inorganic arsenic above the action level without regard to respirator use, or (2) for whom there is the possibility of skin or eye irritation from inorganic arsenic. The employer must assure that employees participate in the training program.
Training must be provided for employees who are covered under this standard, and at least annually thereafter for other covered employees. The employer must assure that each employee is informed of the following:
- The information contained in 29 CFR 1910.1018 Appendix A.
- The quantity, location, manner of use, storage, sources of exposure, and the specific nature of operations that could result in exposure to inorganic arsenic as well as any necessary protective steps.
- The purpose, proper use, and limitation of respirators.
- The purpose and a description of the medical surveillance program.
- The engineering controls and work practices associated with the employer’s job assignment.
- A review of the inorganic arsenic standard.
The employer must make readily available to all affected employees a copy of the Inorganic Arsenic Standard and its appendices.
| Arsenic (inorganic compounds, as As) | CAS 7440-38-2 (metal) |
| As (metal) | RTECS CG0525000 (metal) |
| Synonyms & Trade Names | DOT ID & Guide |
| Arsenic metal: Arsenia | 1558 152 (metal) |
| Other synonyms vary depending upon the specific As compound. [Note: OSHA considers “Inorganic Arsenic” to mean copper acetoarsenite & all inorganic compounds containing arsenic except ARSINE.] | 1562 152 (dust) |
| Exposure Limits | NIOSH REL: Ca C 0.002 mg/m3 [15-minute] |
| OSHA PEL: [1910.1018] TWA 0.010 mg/m3 | |
| IDLH Ca [5 mg/m3 (as As)] See: IDLH INDEX | Conversion |
| Physical DescriptionMetal: Silver-gray or tin-white, brittle, odorless solid. | |||
| MW: 74.9 | BP: Sublimes | MLT: 1135°F (Sublimes) | Sol: Insoluble |
| VP: 0 mmHg (approx) | IP: NA | Sp.Gr: 5.73 (metal) | |
| Fl.P: NA | UEL: NA | LEL: NA | |
| Metal: Noncombustible Solid in bulk form, but a slight explosion hazard in the form of dust when exposed to flame. | |||
| Incompatibilities & Reactivities Strong oxidizers, bromine azide [Note: Hydrogen gas can react with inorganic arsenic to form the highly toxic gas arsine.] | |||
| Measurement Method |
| Filter; Acid; Hydride generation atomic absorption spectrometry; IV [#7900] [Also #7300, Elements] See: NMAM INDEX |
| Personal Protection & Sanitation | First Aid (See procedures) |
| Skin: Prevent skin contact | |
| Eyes: Prevent eye contact | |
| Wash skin: When contaminated/Daily | Eye: Irrigate immediately |
| Remove: When wet or contaminated | Skin: Soap wash immediately |
| Change: Daily | Breathing: Respiratory support |
| Provide: Eyewash, Quick drench | Swallow: Medical attention immediately |
| Respirator Recommendations NIOSH At concentrations above the NIOSH REL, or where there is no REL, at any detectable concentration: (APF = 10,000) Any self-contained breathing apparatus that has a full facepiece and is operated in a pressure-demand or other positive-pressure mode/(APF = 10,000) Any supplied-air respirator that has a full facepiece and is operated in a pressure-demand or other positive-pressure mode in combination with an auxiliary self-contained positive-pressure breathing apparatus Escape: (APF = 50) Any air-purifying, full-facepiece respirator (gas mask) with a chin-style, front- or back-mounted acid gas canister having a high-efficiency particulate filter/Any appropriate escape-type, self-contained breathing apparatus | |
| Exposure Routes inhalation, skin absorption, skin and/or eye contact ingestion | |
| Symptoms Ulceration of nasal septum, dermatitis, gastrointestinal disturbances, peripheral neuropathy, respiratory irritation, hyperpigmentation of skin, [Potential occupational carcinogen] | |
| Target Organs Liver, kidneys, skin, lungs, lymphatic system | |
| Cancer Site [lung & lymphatic cancer] | |
Arsenic checklist
- A written compliance program is in place.
- Employees are aware of the hazards involved with arsenic if they may be exposed to it in their work environment.
- A training program has been instituted for all employees who are subject to exposure to arsenic.
- Employee exposure to arsenic is monitored and kept within acceptable levels.
- Employees are provided with proper protective equipment when working with arsenic.
- Engineering and work practice controls are used to reduce exposures to arsenic to a permissible level.
- Proper precautions are taken when handling arsenic.
- Caution labels and signs are used to warn of arsenic.
- A regulated area has been established, and marked, where arsenic is manufactured, processed, used, repackaged, released, handled, or stored.
- Employees who work with arsenic wash their hands after assigned tasks are completed and before engaging in other activities.
- Arsenic is stored and used appropriately.
- Containers used to store arsenic are appropriately marked.
- All employees who work with arsenic have had an initial medical examination.
- A medical surveillance program is in place for employees who become exposed to arsenic.
- Appropriate records are maintained (exposure monitoring, medical surveillance, etc.).
- Employees are instructed in proper first aid and other emergency procedures.
- Emergency procedures are in place for dealing with emergency situations involving arsenic.