What are Xylenes and how did it get into my drinking water?

Xylenes are chemical solvents used in industrial and consumer products, such as cleaning agents and paint thinners. Xylenes are known to cause nervous system damage and may harm developing fetuses. Xylenes are clear liquids with generally a very sweet odor and it most likely entered your drinking water by contamination from industrial discharge. The greatest use of xylenes is as a chemical solvent which is much safer than benzene. Other uses include: in gasoline as part of the BTX component (benzene-toluene-xylene); Xylene mixtures are used to make phthalate plasticizers, polyester fiber, film and fabricated items.

The list of trade names given below may help you find out whether you are using this chemical at home or work.

Trade Names & Synonyms for Xylenes:

Dimethyl benzene
Violet 3

Why are Xylenes being Regulated?

In 1974, Congress passed the Safe Drinking Water Act. This law requires EPA to determine safe levels of chemicals in drinking water which do or may cause health problems. These non-enforceable levels, based solely on possible health risks and exposure, are called Maximum Contaminant Level Goals.

The Maximum Contaminant Level Goal for xylenes has been set at 10 parts per million (ppm) because EPA believes this level of protection would not cause any of the potential health problems described below.

Based on this MCLG, EPA has set an enforceable standard called a Maximum Contaminant Level (MCL). MCLs are set as close to the MCLGs as possible, considering the ability of public water systems to detect and remove contaminants using suitable treatment technologies.

The MCL has been set at 10 ppm because EPA believes, given present technology and resources, this is the lowest level to which water systems can reasonably be required to remove this contaminant should it occur in drinking water.

These drinking water standards and the regulations for ensuring these standards are met, are called National Primary Drinking Water Regulations. All public water supplies must abide by these regulations.

What are the Health Effects?

Short Term: EPA has found xylenes to potentially cause the following health effects when people are exposed to it at levels above the MCL (Maximum Contaminant Level) for relatively short periods of time: disturbances of cognitive abilities, balance, and coordination.

Long Term: Xylenes has the potential to cause the following effects from a lifetime exposure at levels above the MCL: damage to the central nervous system, liver and kidneys.

How much Xylene is produced and released to the environment?

Production of xylenes was 6.84 billion lbs. in 1993. Major environmental releases of xylenes are due to evaporation from the refining and use of petroleum products. It may also be released by leaks or spills during the transport and storage of gasoline and other fuels. Xylenes are a natural products of many plants, and are a component of petroleum and coal tar.

From 1987 to 1993, according to EPA's Toxic Chemical Release Inventory, xylene releases to land and water totalled nearly 4.8 billion lbs. These releases were primarily from petroleum refining industries. The largest releases occurred in Texas. The largest direct releases to water occurred in New Jersey and Georgia.

What happens to Xylene when it is released to the environment?

Most of the xylenes are released into the atmosphere where they are quickly degraded by sunlight. When released to soil or water, xylenes will quickly evaporate. They may leach into ground water and persist there for several years. There is little potential for accumulation in aquatic life.


How will I know if Xylene is in my drinking water?

If the levels of xylenes exceed the MCL, 10 ppm, the system must notify the public via newspapers, radio, TV and other means. Additional actions, such as providing alternative drinking water supplies, may be required to prevent serious risks to public health.

Xylene Drinking Water Standards:

Maximum Contaminant Level Goal: 10 ppm

Maximum Contaminant Level: 10 ppm

Can I wash my food with Xylene contaminated water?

If xylene levels in your water are above 10 ppm, you should use bottled water or water from a safe source to wash, prepare and cook your food.

Can I irrigate or water my garden with Xylene contaminated water?
Yes, only a small amount of xylene is taken up by plants and it quickly breaks down in soil.

What about bathing and showering in Xylene contaminated water?

Xylene can be absorbed by the skin. Since xylene easily releases from water into the air, bathing and showering with xylene-contaminated water may increase exposure through inhalation. Bathing, swimming and showering with water containing xylene above 10 ppm is not advised.

What about washing dishes, utensils and food preparation areas?

Only a very small amount of water clings to smooth surfaces, such as dishes. Water with xylene can be safely used to wash and sanitize dishes, tables and eating utensils.

What about general cleaning and laundry?

Very little water remains on washed surfaces and in laundered fabrics. Water with xylene can be safely used for general cleaning and washing clothes, bedding and linens.

What about my pets drinking Xylene contaminated water?

Animals should not drink water with xylene levels above 10 ppm.

How do I remove Xylenes from my drinking water?

The regulation for xylenes became effective in 1992. Between 1993 and 1995, EPA required your water supplier to collect water samples every 3 months for one year and analyze them to find out if xylenes is present above 0.5 ppb. If it is present above this level, the system must continue to monitor this contaminant.

The following treatment methods have been approved by EPA for removing xylenes: Granular activated charcoal.  The Epic Smart Shield Under Sink Water Filter has been tested and certified by IAPMO to NSF/ANSI standards to remove Xylenes at the >99% level out to 651 gallons.  

Recent Articles & Videos on Xylenes in Tap Water:

Oregon.gov Website on Xylenes in Tap Water

EWG.org - Database on known Xylene Contamination