Chemical Safety

When you work at a water or wastewater treatment plant, you may be exposed to hazardous chemicals.

Some of the most common include:

  • Chlorine (in one or more of its forms)
  • Sulfur dioxide
  • Caustic soda
  • Soda ash
  • Lime
  • Polymer
  • Methanol
  • Ferric chloride
  • Aluminum sulfate (alum)
  • Ammonia
  • Methane gas
  • Hydrogen sulfide gas
  • Acids (sulfuric, hydrochloric, nitric)
  • Bases (ammonium hydroxide, sodium hydroxide)

In addition to process chemicals, you may have an on-site laboratory, with numerous chemicals used for  testing.  

Rules for Chemical Handling and Safety

Depending on which chemicals you have at your plant, and the amount you store, the following rules may apply. The Occupational Safety and Health Administration (
OSHA) regulates safety for privately owned companies. OSHA might not have legal authority over publicly owned treatment works, but all utilities should follow the OSHA rules and keep everyone safe. In many cases, the state Department of Labor will enforce OSHA rules for publicly owned treatment works. Check with your state and local governments as well, as there may be other safety regulations for those jurisdictions. 

OSHA's Hazard Communication Standard
 (HCS) is a critical rule to know, understand and follow. Also called the “Right to Know” law, it requires all employers with hazardous chemicals in their workplaces to have labels and safety data sheets for their exposed workers, and train them to handle the chemicals appropriately. The Hazard Communication Homepage has a wealth of information in an easy-to-understand format.

OSHA's rule has been updated to align with the Globally Harmonized System of Classification and Labeling of Chemicals (GHS). 

Process Safety Managementof Highly Hazardous Chemicals (PSM), OSHA 29 CFR 1910.119. This rule targets highly hazardous chemicals that could cause catastrophic events resulting in employee deaths. The rule encompasses every aspect of chemical use—system design, written information available (including process flow diagrams and piping and instrument diagrams), operation, employee training, contractors, pre-startup safety, mechanical integrity, non-routine work, and managing change. Employees must be involved in the Process Safety Management development and implementation.

One of the most important elements of the Process Safety Management Program is
Hazard Recognition through a Process Hazards Analysis (PHA). A PHA is a complete evaluation of the chemical process to determine potential hazards associated with handling these materials. During a PHA, employees analyze equipment, instrumentation, utilities, people and their actions, and external factors to find ways to improve safety. The ultimate goal is to reduce the risk of fires, explosions, toxic releases or chemical spills.

The need for Process Safety Management is based on the amount of certain highly hazardous chemicals stored and/or used on site. For instance, the threshold level for chlorine is 1,500 pounds. Any treatment plants that keep more than 1,500 pounds of chlorine on-site must implement Process Safety Management.

OSHA has an easy-to-understand 
Process Safety Management guidebook available. 

U.S. EPA's 
Risk Management Plan, 40 CFR 68.130. The purpose of the Risk Management Plan Rule is to protect the public and the environment from the release of highly hazardous chemicals.

The Risk Management Plan Rule (RMP) is a U.S. Environmental Protection Agency (EPA) regulation, under the Clean Air Act, requiring facilities that produce, use or store highly hazardous chemicals in quantities over specific thresholds to develop a Risk Management Plan which documents the treatment plant’s risk management program. The plans must be submitted to EPA, and reviewed/resubmitted every 5 years.

Elements of the Risk Management Plan can closely track and may overlap those of OSHA’s Process Safety Management (PSM). In fact, many utilities write a combined plan to meet both PSM and RMP requirements. However, be aware that EPA’s thresholds requiring RMP compliance are different from those for PSM.

Risk Management Plans must address three areas--Hazard Assessment, Prevention Program, and Emergency Response Program

Important items for Risk Management Plans include:

·         the analysis of potential offsite consequences for a worst-case accidental release

·         a five-year accident history

·         a release prevention program

·         emergency planning

Appendix F: Supplemental Risk Management Program Guidance for Wastewater Treatment Plants is available on EPA’s website. 

Here's an article on some proposed changes to the Risk Management rule.

Emergency Planning and Community Right to Know Act (EPCRA) is another rule under EPA, and requires planning and reporting on hazardous and toxic chemicals. The “community right to know” provisions give the public access to information on chemicals at various facilities, their uses, and releases.

If hazardous chemicals are present in amounts over the threshold quantities, the facility must cooperate with the state and local government in emergency plan preparation. Treatment plants must submit Material Safety Data Sheets and a chemical inventory to state and local emergency planning officials and the local fire department.

Any spills or releases in amounts over the “reportable quantity” must be reported to state and local officials immediately. A Toxic Release Inventory form must be completed and submitted each year.

Here's a short video with information about EPCRA.

Again - the threshold quantities for chemicals is different between PSM, RMP, and EPCRA - so check carefully to ensure you're in compliance!

This is a summary of the most important regulations regarding chemical safety related to water and wastewater treatment. However, your facilities may be covered by other state or local rules.

Legal Notice and Disclaimer. The materials within this website are for informational purposes only. While the information and recommendations contained on the Treatment Plant Safety website have been compiled from sources believed to be reliable, H2O Writing makes no guarantee as to, and assumes no responsibility for, the correctness, sufficiency, or completeness of such information or recommendations. Other or additional safety measures may be required under particular circumstances. The information on this website is provided only as general information which may or may not reflect the most current legal and safety information. Links from the Treatment Plant Safety website to another domain shall not represent an endorsement..