Chemical Vapors: Frequently Asked Questions

What Are toxic chemical vapors?

There are many ways to describe toxic chemical vapors. Chemical vapor or vapors can include gases, fumes, and particulates. A chemical that is either solid or liquid when at normal room temperature and at normal pressure may turn into a vapor when heated sufficiently, or when the pressure is increased. 

How do Workers come into contact with tank vapors?

There are many pathways in which workers may come into contact with tank vapors. The toxic vapors are in the headspace of the tanks and seep out during atmospheric conditions such as temperature and pressure inversion; during any type of waste disturbing activity such as pumping waste from leaking tanks; when inserting cameras or equipment into tanks; and other times through pipes, vents, filters or anywhere pressure can build and vapors can be released. Tanks must vent to the atmosphere to prevent pressure buildup and possible explosion or tank rupture. 

WHAT CHEMICALS ARE IN HANFORD'S TANK HEADSPACES?

Over 1,800 chemicals have been documented in the vapors in Hanford tank headspaces.  The toxic chemicals found in the tanks, many of which are recognized carcinogens, include ammonia, nitrous oxide, mercury,  hydrocarbons, alcohols, ketones, aldehydes, furans, phthalates, nitriles, amines, and nitrosamines. Many more toxic vapors are known to be in the tanks and have been measured in the tank headspace at concentrations well above occupational exposure limits. Additional chemicals potentially venting from the tanks include dimethyl mercury, benzene, carbon tetrachloride, and n-nitrosodimethylamine (NDMA).

WHAT ARE THE POSSIBLE HEALTH EFFECTS OF EXPOSURE TO TANK VAPORS?

Workers who have been exposed to tank vapors have suffered numerous acute and long-term health effects. These include nosebleeds, metallic taste in the mouth, headaches, coughing, sore throats, nausea, and increased heart rates. Workers have developed chronic obstructive pulmonary disease, decrease in lung capacity, toxic encephalopathy, and cancer as a result of exposure to tank vapors. Some have ended up on long term disability after an exposure.

WHAT STUDIES HAVE BEEN DONE INTO TANK VAPORS AT HANFORD? 

A number of studies on tank vapors at the Hanford Site have been conducted, included the 2003 Government Accountability Project report "Knowing Endangerment: Worker Exposure to Toxic Vapors at the Hanford Tank Farms." The most recent report is the October 2014 Savannah River National Laboratory's Hanford Tank Vapor Assessment Report (commonly referred to as the "TVAT Report"). One conclusion of this report matches those of earlier reports: 

The ongoing emission of tank vapors, which contain a mixture of toxic chemicals, is inconsistent with the provision of a safe and healthful workplace free from recognized hazards.... Management must acknowledge the health risk associated with episodic releases of tank vapors. While the ability to measure and document exposures may currently be inadequate, workers are nonetheless being affected by vapors on the tank farms. Acceptance of this observation should be communicated to all internal and external stakeholders.

WHAT RESOURCES ARE AVAILABLE FOR WORKERS WHO HAVE SUFFERED ADVERSE HEALTH EFFECTS AFTER A CHEMICAL VAPOR EXPOSURE?

We are working on updating our site to include the most up to date chemical vapor exposure resources for workers. In the meantime, please email info@hanfordchallenge.org with questions and concerns.