Do LED Grow Lights Emit UV Rays? Learn About LED Grow Light Safety

PDF download Download Article
PDF download Download Article

Public interest in indoor gardening is blooming, and lighting technology has grown to support it! Starting seeds early, enjoying veggies year round, and protecting delicate leaves from pests are just some of the reasons to bring your garden inside. Your indoor garden will need an indoor sun, which is where LED grow lights enter the picture. This fairly new tech has germinated a lot of questions about UV radiation and safety, so read on to find out what facts about LED grow lights have emerged from the dark.

Question 1 of 7:

Do LED grow lights emit UV rays?

PDF download Download Article
  1. UV rays, also known as ultraviolet radiation and ultraviolet light, are emitted from natural sources, like the sun, and artificial sources, like tanning beds and some kinds of lights. Although overexposure to UV radiation can cause cancer, in small amounts, UV exposure is beneficial for both humans and plants, stimulating vitamin D production in people and robust growth in plants. [1] This is why many LED grow lights have been specially engineered to emit UV (most LED household lights don’t emit any). [2] Other kinds of grow lights, such as HID (high intensity discharge) lights, also emit UV light.
    2. Advertisement
Question 2 of 7:

Why do grow lights emit UV light?

PDF download Download Article
  1. Although UV radiation can be harmful to both plants and animals in large amounts, within correct ranges, UV light encourages indoor plants to be stronger, brighter, and more resilient. [3]
    • Plants exposed to UV light were not only more disease resistant, but also made bigger fruit (and more of it). [4] [5]
Question 3 of 7:

Do the UV rays from LED grow lights cause cancer?

PDF download Download Article
  1. The UV from most sources of indoor lighting is not harmful to humans, but the higher intensity of grow lights’ UV radiation is worth being mindful of, particularly for those with a family history of skin cancer. You can moderate your exposure to UV radiation from your LED grow lights by wearing long-sleeved shirts, hats (if the light is installed overhead), choosing grow lamps with lower UV intensities, and only using the lights for the recommended amount of time. [6]
    2. Advertisement
Question 4 of 7:

Do LED grow lights damage eyes?

PDF download Download Article
  1. Because LEDs are a fairly new technology, researchers are still studying the long-lasting effects of LED exposure. However, early research tentatively suggests humans limit their exposure to all blue light—(which is the peak spectral output of LEDs)— to avoid skin and eye damage. [7]
    • Smartphones, laptops, desktop computers, and tablets also emit blue light.
    • Some studies suggest that just one hour of exposure is enough to generate oxidative stress, encouraging wrinkles and other premature aging!
    • Try using glasses with amber lenses to protect your eyes from all forms of blue light. [8]
Question 5 of 7:

Do LED grow lights contain heavy metals?

PDF download Download Article
  1. In the past, LED lights contained many heavy metals such as lead and mercury. [9] However, technology has changed since then and LED lights no longer contain harmful materials. [10]
    2. Advertisement
Question 6 of 7:

Is it safe to leave your LED grow lights on all the time?

PDF download Download Article
  1. LED grow lights are cooler and more efficient to run than other kinds of grow lights, but most plants require a daily period of darkness in order to thrive.
    • Most plants require 6 hours of darkness to regenerate phytochrome, which is important to regulate seed germination, among other processes. [11] Generally speaking, for bright light plants, you might need to use the light for 8 to 10 hours a day.
Question 7 of 7:

Does leaving my grow lights on all the time create better growth?

PDF download Download Article
  1. [12] Ordinary fluorescent shop lights will need to run much longer than intense HID lights. A plant cozied right up to a light source will need fewer hours of light than a plant placed several yards away.
    • DLI (Daily light integral) measures the amount of quality light a plant receives. [13]
    • Plants’ DLI needs vary based upon species, stage of life, and the season. Tender microgreen sprouts can make do with the natural light of a windowsill, but energy-starved fruiting tomato plants will need a lot of intense light to mimic the power of the summer sun. [14]
    2. Advertisement

Expert Q&A

Ask a Question
200 characters left
Include your email address to get a message when this question is answered.
Submit
      Advertisement

      Tips

      Submit a Tip
      All tip submissions are carefully reviewed before being published
      Name
      Please provide your name and last initial
      Submit
      Thanks for submitting a tip for review!

      Warnings

      • Not all plants thrive under LED grow lights, so do some research about your specific plant before depending or investing in this kind of equipment.
        Thanks
        Helpful 2 Not Helpful 0
      • For certain plants, you also have to consider the placement of the light, since they cannot be too close. Direct and close rays for a long time can actually scorch your plants.
        Thanks
        Helpful 2 Not Helpful 0


      Advertisement

      You Might Also Like

      Easiest Way to Install LED Strip Lights
      How to
      Test LED Lights
      How to
      Cut Led Strip Lights
      How to
      Make a Homemade Flashlight
      How to
      Daisy Chain Lights
      How to
      Hang Fairy Lights
      How to
      Install a New Light Fixture
      How to
      Wire a Light
      How to
      Install a New Ceiling Light Fixture
      How to
      Install a Pendant Light
      How to
      Connect LED Strip Lights
      How to
      Replace a Fluorescent Light Cover, Tube, or Fixture
      How to
      Test Fluorescent Bulbs
      How to
      Replace a Recessed Bulb (Without Removing the Fixture!)
      Advertisement

      References

      1. ↑ https://www.cdc.gov/nceh/features/uv-radiation-safety/index.html
      2. ↑ https://iopscience.iop.org/article/10.1088/0268-1242/29/8/084004
      3. ↑ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8408258/
      4. ↑ https://www.mdpi.com/2311-7524/7/1/9/htm
      5. ↑ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8408258/
      6. ↑ https://deohs.washington.edu/nwcohs/blog/over-exposure-uv-light-hazard-cannabis-growing-facilities-uw-researchers-say-yes
      7. ↑ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6280109/
      8. ↑ https://pubmed.ncbi.nlm.nih.gov/20030543/
      9. ↑ https://www.scientificamerican.com/article/led-lightbulb-concerns/
      1. ↑ https://www.epa.gov/sites/default/files/2014-12/documents/technology_assessment_of_light_emitting_diode.pdf
      2. ↑ https://calgary.rasc.ca/lp/plants.html
      3. ↑ https://extension.unh.edu/resource/growing-seedlings-under-lights-fact-sheet
      4. ↑ https://www.extension.purdue.edu/extmedia/ho/ho-238-w.pdf
      5. ↑ https://growhotpeppers.com/indoor-grow-lights/

      About This Article

      Thanks to all authors for creating a page that has been read 29,699 times.

      Did this article help you?

      Advertisement