Dried blood is generally considered safe to touch for most people. However, there are some risks and precautions to keep in mind when handling dried blood.
Is dried blood infectious?
The main concern with coming into contact with dried blood is the potential for transmission of bloodborne pathogens like hepatitis B (HBV), hepatitis C (HCV), and human immunodeficiency virus (HIV). However, the risk is very low. Here’s why:
- Most infectious pathogens don’t survive long once blood has dried. Studies show HCV remains infectious for up to 6 weeks in dried blood and HBV up to 7 days. HIV is less stable and usually cannot be detected within hours to days.
- It takes a fairly large amount of blood and a break in the skin to transmit bloodborne viruses. Dried blood generally doesn’t contain enough active virus to cause infection, especially through casual intact skin contact.
- Bloodborne viruses die off over time. The older the dried blood, the less infectious it becomes.
While not impossible, transmission of a bloodborne illness from touching dried blood is very unlikely. However, those with a compromised immune system or open cuts or sores on their hands may want to take extra precautions.
Is it safe to touch my own dried blood?
It’s generally safe to handle your own dried blood. Since you cannot transmit viruses you don’t already have, there is no risk of contracting a bloodborne illness from your own blood.
However, you may still want to take some basic precautions:
- Use gloves – This protects you from any other pathogens that may be present.
- Clean hands after – Wash with soap and water to remove any lingering blood.
- Bandage cuts – Cover any open wounds, sores, or hangnails first.
As long as you aren’t actively bleeding, touching dried blood from a prior injury on yourself poses minimal risk.
Can I get HIV or hepatitis from touching dried blood?
Contracting HIV, hepatitis B, or hepatitis C from casual contact with dried blood is extremely unlikely.
Here are some key points about transmission risks:
- HBV – Dried blood contains very little infectious HBV. You would need to touch a fair amount and have damaged skin for transmission.
- HCV – HCV can remain infectious for up to 6 weeks in dried blood. But average risk is 1.8% even with blood exposures to mucous membranes.
- HIV – HIV cannot survive more than a few hours to days when dried. Intact skin contact poses close to zero risk.
To acquire these viruses from dried blood, you would need a significant amount of still infectious blood to directly contact broken skin or get into your bloodstream. Even health care workers who routinely handle blood samples have a low infection risk.
When is dried blood no longer infectious?
There is no definitive “expiry date” for when dried blood becomes non-infectious. The duration bloodborne pathogens can survive depends on factors like:
- Type of pathogen – HIV dies off quickest. HCV can last up to 6 weeks.
- Temperature – Colder temperatures prolong viral survival.
- Sunlight – UV rays accelerate virus degradation.
- Surface material – Porous surfaces preserve viruses better than non-porous.
- Blood volume – Larger amounts take longer to dry and die off.
However, as a general rule of thumb:
- HBV remains infectious for about 1 week once blood has dried.
- HCV can survive for up to 6 weeks before becoming non-infectious.
- HIV typically cannot be transmitted from blood dried over 48 hours.
If ever in doubt, taking precautions is recommended even with blood that is weeks to months old.
Can I get sick from touching old dried blood?
It’s unlikely you would get sick from touching moderately old dried blood. Blood that is weeks to months old generally does not pose an infection risk, even for viruses like hepatitis C.
Here are some reasons older dried blood is less concerning:
- Viruses degrade over time and due to exposure to air and light.
- The small amount left may not be enough to cause infection.
- There is lower likelihood of transmission through intact skin.
The exception would be extremely large, fresh blood stains that have barely begun drying. But for most day-to-day encounters with dried blood, the risk of illness is very low, especially if you have no cuts and wash hands after.
Can I get an STD from dried blood?
It’s very unlikely to contract a sexually transmitted disease (STD) like HIV, hepatitis B, herpes, or syphilis from casual contact with dried blood.
STD transmission through dried blood requires:
- A high enough concentration of infectious virus or bacteria.
- Entry into the bloodstream such as through broken skin or mucous membranes.
Since dried blood contains lower pathogen levels and intact skin protects against infection, the risk of STD transmission is extremely small. However, those with compromised immunity may want to take extra care.
Is menstrual dried blood safe?
Menstrual dried blood carries the same low risks as other types. As long as you are not currently menstruating, handling dried period blood is unlikely to pose a health hazard.
However, menstrual blood potentially contains more pathogens than regular blood. During menstruation the cervix opens slightly which provides an opportunity for bacteria to enter the uterus.
While these bacteria are not necessarily dangerous, it provides an argument for taking sensible precautions when handling dried period blood, such as:
- Using gloves if cleaning up large amounts
- Washing hands thoroughly afterwards
- Disinfecting any surfaces stained
Following basic hygiene practices reduces an already low infection risk even further.
Who should avoid contact with dried blood?
While dried blood exposure is low-risk for most healthy people, some groups are better off avoiding contact when possible. This includes:
- People with weakened immune systems – HIV, chemotherapy, steroids raise infection susceptibility.
- People with chronic liver disease – More prone to hepatitis B and C infection.
- Pregnant women – At risk of bloodborne illnesses infecting the fetus.
- People with skin conditions – Weeping eczema, psoriasis provide virus entry points.
Those with high infection vulnerability are best off avoiding exposure to potentially infectious substances like blood whenever feasible.
How to safely clean dried blood
Cleaning up dried or old blood stains carries minimal risk. But you may want to take a few precautions, including:
- Wearing waterproof gloves to protect your hands
- Using a disinfecting cleaner or bleach solution
- Avoiding scrubbing or agitating the blood which can aerosolize particles
- Placing rags or paper towels in a sealed plastic bag for disposal
- Mopping then disinfecting the area afterwards
For small amounts of blood, general household cleaning is usually sufficient. Just remember to wash hands thoroughly after.
Is it safe to touch dried blood from someone else?
Use caution when handling dried blood from other people. While risks are low, you may consider:
- Wearing waterproof gloves if cleaning large amounts
- Using disinfectant and avoiding creating splashes or spray
- Sealing any blood-stained rags or paper towels in a plastic bag
- Washing hands, forearms, and any other exposed skin afterwards
When scrubbing or disinfecting, the goal is to avoid inadvertent contact. This provides an added safety buffer for this already low transmission risk activity.
Can I get sick from old blood in unwashed clothes?
It’s unlikely you would get sick from exposure to dried blood left on unwashed clothing. However, it’s smart to launder clothes stained with blood.
Viruses like hepatitis B, C and HIV cannot survive for long once blood has dried. And intact skin contact generally poses little risk.
However, laundering eliminates any residual infection risk. Be sure to:
- Handle contaminated clothes with gloves
- Rinse or soak in cold water before washing
- Disinfect laundry hampers or bags afterwards
With proper precautions, potential pathogen exposure from soiled clothes is extremely minimal.
Can touching dried blood make me nauseous?
Yes, dried blood can sometimes cause nausea or make you feel unwell. Here’s why:
- Smell – Blood has a metallic odor that can trigger nausea in sensitive people.
- Vision – Seeing dried blood may induce a visceral reaction.
- Stress – Anxiety about bloodborne illness risks can cause nausea.
- Movement – Getting lightheaded is common if getting up too quickly after sitting by blood.
To reduce the chances of feeling sick:
- Avoid strong smells by turning your head away and breathing through your mouth
- Look away until you feel less dizzy or anxious
- Get up slowly and stabilize yourself if you’ve been kneeling or crouching
The nausea should pass quickly once you remove yourself from the trigger. See a doctor if it persists.
Conclusion
In most situations, brief contact with dried blood is safe and presents a very low infection risk. However, it’s smart to exercise basic precautions like:
- Wearing waterproof gloves during clean-up
- Disinfecting soiled surfaces
- Washing hands and skin after exposure
- Avoiding contact if you have any open cuts or sores
While not inherently dangerous, handling blood still warrants care to minimize any potential health hazards. With sensible practices, dried blood is generally nothing to worry about.