Miox : My Water. My World.

Operator Safety

One of the clear advantages to the MIOX technology is the very significant reduction in all risks currently associated with conventional chlorination technology, especially as these risks present themselves to water system operators and the community.

Danger: Chlorine Gas

Pressurized chlorine
gas cylinders

The most common disinfectant, chlorine gas, is a deadly poison that can kill a person exposed even to low doses. The chlorine gas enters the lungs and reacts with moisture in the lungs to create hydrochloric acid. The acid then burns the lungs, generating liquid that causes asphyxiation. Since operators are required to handle and change out chlorine cylinders on a periodic basis, the risk factor of their job is high. Operators are also exposed when maintaining or servicing the venturi injection systems that are used to add the chlorine to the water supply. Most water operators using chlorine gas have had some unpleasant exposure to a chlorine gas leak. Strict safety rules for storage and handling of chlorine cylinders include the EPA’s Risk Management Plan (RMP), HAZMAT training, use of Self-Contained Breathing Apparatus (SCBA), Department of Transportation regulations, and the “two-man rule” for changing out chlorine cylinders.

Real life hazard — Real life stories

• November 2005:
  Chlorine gas injures 6
  (Penn State University)
• January 2005
  Chlorine gas kills 8, injures 200
  (Graniteville, SC)
• June 2004
  Chlorine gas kills 2, injures 50
  (San Antonio, TX)
• July 2003
  75 workers and hundreds of children evacuated
  (Valhalla, NY)
• November 2001
  Chlorine gas injures 33
  (Kearneysville, WV)
• June 2001
  Chlorine gas injures 4
  (Tampa, FL)
• February 1998
  4000 evacuated due to chorine gas
  (Morristown, TN)
• 1996 DOE determines the most hazardous substance at their facilities, aside from nuclear materials, is chlorine gas.

Danger: Delivered Hypochlorite

In an effort to reduce the regulatory burden and improve working environments, many water treatment plants have converted to bulk sodium hypochlorite. Hypochlorite is typically sold at concentrations of 10 to 15 percent strength, which tends to off-gas. The “safety-in-use risk” of commercial hypochlorite is actually higher than that of chlorine gas, with the accident rate for sodium hypochlorite more than six times that of chlorine gas, according to the American Association for Poison Control. Since commercial hypochlorite is perceived to have low potential to cause fatalities, little regulatory attention has been focused on the actual rate of incidents, leaving no risk management practices in place to protect the operator from potential mishandling. Despite the lack of regulatory control, sodium hypochlorite spills release chlorine gas, chlorine gas can be formed by interactions with other chemicals, and spontaneous ignition can be provoked by a heat source.

Real life hazard — Real life stories

• “Chlorine is both helper, hazard”,
  Daily Bulletin.com. May 27, 1997.
  In Pomona, CA in 1997, a tank cracked causing a massive leak of sodium hypochlorite. Plant personnel attempted to wash down the leak and inadvertently caused a chlorine gas cloud which overcame two auto mechanics next door.
• “Chemical Explosion Kills One”,
  Alamogordo Daily News. August 14, 1999.
  In 1999 in Alamogordo, NM, a chemical transfer of bleach injured five workers in an explosion and killed one man who died from burn injuries.
• “Ohio Officials Evacuate Water Plant after Toxic Mistake”,
  Morning Journal News. October 24, 2003.
  In 2003 in Ohio, an employee mistakenly mixed five gallons of sodium hypochlorite with 15 gallons of hydrofluorosilicic acid, causing a toxic fume. He was taken to the hospital for treatment while a hazmat crew secured the chemicals.
• “290 East Open Again after Chlorine Leak”,
  KXAN.com. May 26, 2006.
  On May 26, 2006, in Austin, a haz-mat team worked most of the afternoon to contain a liquid chlorine leak from a tanker truck that closed down US Highway 290.  The truck driver himself was taken to the hospital and treated for breathing problems. Residents and students had to be evacuated, with the leak impacting an elementary school, middle school, and high school.  Local resident Herschel McFarland said, “You smell it. You’ll know what it is, you know. I mean you know it’s bleach. It’s just a big smoke fog, you know, when it goes out, and you can see it coming. We both have breathing problems, and it affected us. So really it’s probably best that we don’t even go back."

Solution: On-Site Generated Hypochlorite

In contrast, on-site generation of hypochlorite uses only salt, water, and power as feedstocks. Neither the salt nor the hypochlorite produced is classified as hazardous by the regulatory agencies. The concentration of the generated chlorine solution is below the Hazardous Communications Standard (HCS) safety threshold limit of 1 percent. Although hydrogen gas is evolved from the electrolytic process of on-site generation, automatic venting designs or air dilution systems safely vent this gas to the atmosphere. On-site generation has an excellent safety record, with more than 4,000 units, from a variety of manufacturers, installed worldwide.