What is boron?
Boron is an element found in nature. It is most often combined with oxygen in compounds called borates (e.g., boric acid, borax, boron oxide). Minerals with borate are mined and processed to make:
- glass
- ceramics
- soap
- bleach
- detergent
- fire retardant
- industrial pesticides
Where is boron found?
Boron is released into air, water, or soil when soils and rocks naturally weather.
Man-made sources of boron include:
- some fertilizers and herbicides
- copper smelters
- wastewater used for irrigation
- industrial waste disposal
How might I be exposed to boron?
There can be boron (usually as borates or boric acid) in:
- some cosmetics
- drinking water
- some pesticides
- certain foods (e.g., fruits and vegetables)
- powders or dusts that you breathe in
- some medicines
How does boron get into my water?
Boron gets into water from:
- industrial wastewater
- municipal sewage
- rocks and soil weathering
- soil run-off
What effects does boron have on my health?
Most people have a daily intake of about 1.2 mg of boron from their diet. Most drinking water contains between 0.1 and 0.3 milligrams per litre (mg/L). People and animals absorb most of the boron into their gastrointestinal (GI) and respiratory systems and urinate it out.
According to the Environmental Protection Agency (EPA) in the USA, there is a risk to a young boy’s testicles when boron (in drinking water) is over the 1-day and 10-day health advisory (3.0 mg/L) and long-term health advisory (2.0 mg/L) for children.
Do not use water with boron over these levels to prepare food or formula for babies and children. If boron levels are over the long-term health advisory and lifetime health advisory for adults (5 mg/L), there is a risk to testicles and unborn babies.
Boron does not cause cancer.
What is the standard for boron in drinking water?
According to Health Canada, the highest acceptable level of boron in drinking water is 5 mg/L.
According to the World Health Organization, the health-based guideline for boron level in drinking water is 2.4 mg/L.
How do I know if there is boron in my drinking water?
Any public water supply must be checked for boron. You can find out results from the supplier. If routine monitoring shows boron levels over the MAC, the water supplier has to reduce the amount of boron to a safe level.
If you have a private water source, test your water regularly to make sure it is safe. Make sure to have your water sample tested by an accredited lab.
What if I find boron in my drinking water?
If you are concerned about boron in drinking water:
- use water from another safe source (e.g., municipal system, bottled water) to drink, cook, and brush teeth
- talk to a professional water specialist to install a certified water treatment unit to remove boron.
The three ways to lower boron levels to below 0.3 mg/L are with:
- a boron-specific ion exchange resin
- a strong-base anion-exchange resin
- reverse osmosis (limited ability)
After you have installed your system, have the treated water tested for boron to make sure your system is working properly. Monitor and maintain your water treatment equipment according to manufacturer instructions.
If you have any questions about boron in water, call Environmental Public Health.
