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NIOSH Safety and Health Topic:

Venomous Snakes

Venomous snakes found in the United States include rattlesnakes, copperheads, cottonmouths/water moccasins, and coral snakes. They can be dangerous to outdoor workers including farmers, foresters, landscapers, groundskeepers, gardeners, painters, roofers, pavers, construction workers, laborers, mechanics, and any other workers who spend time outside. Although rare, some workers with a severe allergy to snake venom may be at risk of death if bitten. It has been estimated that 7,000–8,000 people per year receive venomous bites in the United States, and about 5 of those people die. The number of deaths would be much higher if people did not seek medical care. It is important for employers to train their workers about their risk of exposure to venomous snakes, how they can prevent and protect themselves from snake bites, and what they should do if they are bitten.

Types of Venomous Snakes

Rattlesnakes | Copperheads | Cottonmouths/Water Moccasins | Coral Snakes


Photos courtesy of U.S. Fish and Wildlife Service (1 & 2) and Edward J. Wozniak (3)

There are many species of rattlesnakes in the United States. Rattlesnakes are the largest of the venomous snakes in the United States. They can accurately strike at up to one-third their body length. Rattlesnakes use their rattles or tails as a warning when they feel threatened. Baby rattlesnakes may actually be more dangerous because they do not have control over how much venom they inject when they bite. Rattlesnakes may be found sunning themselves near logs, boulders, or open areas. These snakes may be found in most work habitats including the mountains, prairies, deserts, and beaches.

U.S. Geographic Region: Across the United States.


Photos courtesy of U.S. Fish and Wildlife Service (1 & 2) and Edward J. Wozniak of CDC (3)

Copperheads vary in color from reddish to golden tan. The colored bands on their body are typically hourglass-shaped. Most adults are 18� inches long. They are not usually aggressive, but will often freeze when frightened. Workers are more likely to be bitten when they unknowingly step on or near a copperhead. Copperheads are often found in forests, rocky areas, swamps, or near sources of water like rivers.

U.S. Geographic Region: Eastern states, extending as far west as Texas.

Cottonmouths/Water Moccasins

Photos courtesy of U.S. Fish and Wildlife Service (1 & 2) and Edward J. Wozniak (3)

Cottonmouth snakes average 5� inches long. The adult snake抯 skin is dark tan, brown, or nearly black, with vague black or dark brown crossbands. Juveniles have a bold crossbanded pattern of brown or orange with a yellow tail. Cottonmouths are frequently found in or around water. They do not scare easily and will defend themselves when threatened.

U.S. Geographic Region: Wetland areas, rivers, lakes, etc., in the southeastern states.

Coral Snakes

Photos courtesy of U.S. Fish and Wildlife Service (1) and Edward J. Wozniak (2)

These snakes are often confused with nonvenomous king snakes, which have similar colored bands although in a different arrangement. However, if the red bands are touching the yellow bands, then it is a venomous coral snake. Coral snakes tend to hide in leaf piles or burrow into the ground.

U.S. Geographic Region: Wooded, sandy, or marshy areas of the Southern United States.


Signs or symptoms associated with a snake bite may vary depending on the type of snake, but may include:

  • A pair of puncture marks at the wound
  • Redness and swelling around the bite
  • Severe pain at the site of the bite
  • Nausea and vomiting
  • Labored breathing (in extreme cases, breathing may stop altogether)
  • Disturbed vision
  • Increased salivation and sweating
  • Numbness or tingling around your face and/or limbs

Recommendations for Protecting Workers

Employers should protect their workers from venomous snake bites by training them about:

  • Their risk of exposure to poisonous snakes
  • How to identify poisonous snakes
  • How to prevent snake bites
  • What they should do if they are bitten by a snake

Preventing Snake Bites

Workers should take the following steps to prevent a snake bite:

  • Do not try to handle any snake.
  • Stay away from tall grass and piles of leaves when possible.
  • Avoid climbing on rocks or piles of wood where a snake may be hiding.
  • Be aware that snakes tend to be active at night and in warm weather.
  • Wear boots and long pants when working outdoors.

First Aid

Workers should take the following steps if they are bitten by a snake:

  • Try to remember the color and shape of the snake, which can help with treatment of the snake bite.
  • Keep still and calm. This can slow down the spread of venom.
  • Seek medical attention as soon as possible (dial 911 or call local Emergency Medical Services.)
  • Inform your supervisor.
  • Apply first aid if you cannot get to the hospital right away.
    • Lay or sit down with the bite below the level of the heart.
    • Wash the bite with soap and water.
    • Cover the bite with a clean, dry dressing.

Do NOT do any of the following:

  • Do not pick up the snake or try to trap it.
  • Do not apply a tourniquet.
  • Do not slash the wound with a knife.
  • Do not suck out the venom.
  • Do not apply ice or immerse the wound in water.
  • Do not drink alcohol as a painkiller.
  • Do not drink caffeinated beverages.

CDC Resources

CDC Emergency Preparedness and Response: How to Prevent or Respond to a Snake Bite
En Espa駉l

CDC Snakes: Pictorial Key to Venomous Species in the United States
this document in PDF 844.95 KB (4 pages)

Additional Resources

Occupational Safety and Health Administration � Fact Sheet: Cottonmouth Snakes (Water Moccasin)
this document in PDF 29.77 KB (1 page)

Food and Drug Administration � For Goodness Snakes! Treating and Preventing Venomous Bites
External link:

Florida Museum of Natural History抯 Guide to Florida抯 Venomous Snakes
External link:

North Carolina State University Cooperative Extension: Avoiding Snake Bites
External link:

Texas A&M University � Texas Cooperative Extension: Snakes and Their Control
External link:

Page last updated: October 22, 2008
Page last reviewed: October 22, 2008
Content Source: National Institute for Occupational Safety and Health (NIOSH)

Venomous Snakes


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