FAQs About Chemical Vapors

1What are chemical vapors and where do they come from?
Hanford’s 177 underground waste tanks contain a complex mixture of radioactive materials and hazardous chemicals. In fact, more than 1,800 chemicals have been identified in the tank waste. Of these, about 1,500 chemicals are present in the headspace of the tanks, which need to be vented to the atmosphere to prevent potentially flammable concentrations of gases in the tanks. The vapors are filtered to remove radioactive contaminants, but chemical vapors have the potential to enter workers’ breathing space.
2What is an AOP-015?
Chemicals are routinely monitored in the tank farms. When a Personal Ammonia Monitor alarm occurs the TF-AOP-015 (Tank farm - Abnormal operating procedure - #015) is initiated.

In the event of an AOP-015, the affected area is evacuated and employees are moved upwind. Other workers in adjacent areas are notified. Access to the area is restricted. Employees who exhibit symptoms are sent to the onsite medical provider for an evaluation. Medical evaluation is also offered to employees who don’t have symptoms.
3What is WRPS doing to protect workers?
Washington River Protection Solutions has continued to improve its tank farm industrial hygiene program with additional staff, new equipment, updated procedures, and improved worker training.
  • During waste-disturbing activities, such as when waste is retrieved from tanks, additional controls are put in place to protect workers.
  • Vapor Control Zones are established and workers inside them are required to wear a self-contained breathing apparatus with a bottled-air supply.
  • More than 1,500 chemicals were identified in the tank headspaces, with a Technical Basis identifying 61 as Chemicals of Potential Concern to workers.
4What are COPCs?
The foundation for the Hanford tank farms Chemical Vapor Program is a Technical Basis established by an independent panel of experts. The Technical Basis integrated the results of waste characterization, toxicology, field monitoring, personal sampling, environmental modeling, and chemical process data for the tank farms. The Technical Basis characterized the chemicals in the tank waste and the tank headspaces, identified the 61 chemicals of potential concern and established occupational exposure limits for the COPCs. The Technical Basis has been reviewed by outside experts and determined to be appropriate for Hanford’s tank farms. Using accepted industry data and independent experts, Occupational Exposure Limits (OELs) were established for all of the COPCs. Federal law mandates that worker exposures be kept below 50 percent of the OELs. Administrative limits for Hanford tank farm workers were set at 10 percent of the federal OELs. The tank farms industrial hygiene program meets National Institute for Occupational Safety and Health (NIOSH) protocols. For a complete list of the COPCs, click here.
5What are OELs?
Occupational Exposure Limits (OELs) protect workers and prevent long-term health effects. OELs have been established for all 61 Chemicals of Potential Concern (COPCs). Federal law mandates that worker exposures be kept below 50 percent of the OELs. WRPS has instituted Administrative Control Levels for COPCs at 10 percent of the OELs.
6How are vapors managed?
WRPS uses a hierarchy of controls to manage chemical vapors in Hanford’s tank farms.
  1. Eliminate vapor sources
  2. Establish administrative controls
  3. Install engineered controls
  4. Provide personal protective equipment
There are high concentrations of chemicals in the headspace of Hanford’s underground waste tanks. The headspace is the area inside the tank between the surface of the waste and the domed top of the tank. Openings to the 75-foot diameter headspace, called risers, protrude through the soil above the tanks. “Fugitive vapors” – chemical vapors that migrate from the tank headspace into the work areas through openings in the tank dome for pipes, instrument cables and openings in valve pits – are controlled by sealing the pathways with foam. Periodic monitoring is conducted to discover and control fugitive vapors in an ongoing effort to keep them out of the workers’ breathing space.
7What kind of respiratory protection is used?
Respiratory protection is another component of the Industrial Hygiene program. Tank farm workers are supplied with a variety of respiratory protection equipment, including use of supplied air. Due to an ongoing Stop Work order, any work conducted within a tank farm requires the use of a supplied-air respirator. Workers wear a self-contained breathing apparatus, or SCBA, that provides fresh air from a bottle on the worker’s back. Bottles typically have a 30- to 60-minute supply of air. SCBA units provide fresh air through a regulator that is attached to a mask that seals to the user’s face. SCBA is the respiratory protection prescribed for situations that require the most protection.
8What is the forward-looking plan to further enhance worker protection?
The Tank Vapor Assessment Team, or TVAT, report was issued by a team of independent experts led by the Savannah River National Laboratory. The TVAT has 10 overarching recommendations and 47 specific recommendations to enhance the WRPS Industrial Hygiene program. WRPS established a TVAT Implementation Plan that addresses all the recommendations in the report. The plan is a multi-year, phased project.
  • Phase 1— Program enhancement; data collection & testing; R&D; recommendations for Phase 2
  • Phase 2 — Complete R&D; deploy new technology/equipment; institutionalize controls
  • To read the TVAT report in its entirety, click here.

    Subsequently, a number of expert panels have evaluated WRPS programs and the work being performed at the tank farms. These included: DOE EA-32, Center for Disease Control, National Institute for Occupational Safety and Health (NIOSH) and the Hanford Vapors Expert panel, amongst others. Additionally, Stoneturn Consultants (STC), third-party independent consultant representing the Hanford Atomic Metal Trades Council under the HAMTC/WRPS Memorandum of Agreement, reviewed the IH program with a specific focus on cartridge testing. Later, STC reviews took a broader, more holistic approach to the tank farms work to evaluate the effectiveness of engineering controls and other methods. The combined assessments resulted in 371 recommendations this culminated with the Comprehensive Vapor Action Plan and its implementation. link here.
9We have sixty-one Chemicals of Potential Concern (COPCs) that have been identified in the tank headspace. And each COPC has an Occupational Exposure Limit (OEL), with some OELs that are lower than the ability of direct reading instruments (DRI) to detect in real time.

How are we going to protect workers wearing Air Purifying Respirators (APR's) from COPC's with OEL's that are lower than the ability of DRI's to detect in real time?
Workers are protected from potential effects of airborne chemicals by wearing the minimum level of respiratory Personal Protective Equipment (PPE) that still provides adequate health protection. The selection of the APR as respiratory protection is made by the Industrial Hygienist (IH) based collectively on personal, source, and area sampling data, as well as available monitoring data. The level of protection and the designated filter cartridge are prescribed by the WRPS IH program on the Respiratory Protection Form (RPF). The personal, area, and source data are considered because of the Direct Reading Instrumentation (DRI) limitations to detect some of the COPCs in real time.

The APR filter cartridges currently in use have been tested for breakthrough against levels of headspace vapors that have been measured in the tank farms. The test results have shown that the results meet the manufacturers recommendations. Those reports can be reviewed at this link.

Let’s look at how DRI information is used by the IH in real time. When the headspace vapors are emitted from inside the tank to the tank farm air, all of the individual chemicals in the mixture are diluted to the same extent. Although they each dilute to far lower concentrations once outside of the tank, the ratio of one chemical to another is the same as it was in the tank headspace. This relationship allows us to use DRI to monitor one or more of the TVIS compounds to determine when an upset condition occurs. This is the basis of leading indicator(s) principles. Here is a link to the leading indicators report.

An example will illustrate how this works: Imagine a tank headspace with only two compounds: 100 ppm ammonia and 5 ppb n-nitrosodimethylamine (NDMA). The rest of the headspace is made up of plain air.

When these gases exit the stack or breather filter, they are both diluted equally. To simplify the math for our example, let’s assume a dilution factor of 100. That results in a tank farm air concentration of 1 ppm ammonia and 0.05 ppb NDMA. Even though we cannot measure the 0.05 ppb (which is below the OEL) of NDMA with DRI, we can easily measure the 1 ppm of ammonia which comes along with it.

Now let’s imagine that the DRI reading for ammonia changed from around 1 ppm up to, say, 10 ppm. The IHT would know something in the farm area or inside the tank had changed. At that point, the work area would be put into a safe condition, and personnel would exit until IH had either determined the cause of the upset, or that conditions had returned to normal, at which time work could re-commence.

In this case, we do not need to know the NDMA level in real time to be assured that the workers are still safe. We understand that NDMA would increase in the same ratio as ammonia. Although it would be at about 0.500 ppb (above the 8-hour time-weight average OEL level), the IH action would quickly remove everyone from the area. Thus, workers would be in air containing NDMA for just seconds or minutes before they are evacuated, far less than the 8 hours on which the acceptable limit is based. So, if the APR cartridges worn by the workers have been shown to filter out headspace levels of NDMA for hours at a time, and the workers leave the area after just minutes of being in NDMA above the OEL level, then we are confident that there is no risk to the workers of adverse effects from these headspace vapors.

Engineering Controls

1Does WRPS have a summary of prior and ongoing engineering control evaluation reports?

Q&A Issue #1

This is an in-progress document providing answers to employee questions raised in 2015. Q&As have been placed in general categories for ease of use. Answers may be updated as new information is developed or when evaluations of the item are completed.

Bottle Pilot

1Are the personal evacuation bottles listed as a personal sample?
No, the evacuation bottles are considered area/grab samples.
2Where are the bottles being piloted?
They will be piloted where a Self-Contained Breathing Apparatus (SCBA) is not used, inside and outside the tank farms fence line and as part of the pilot test in AP and A farms.
3How long do the bottles draw? Are we placing workers in risk while they activate the bottles?
Workers will not be placed at risk. The personal sample bottles are easy to activate and draw for less than one second. They are 450 mL bottles.
4What will the personal evacuation bottle be sampled for in the lab?
The bottles will be analyzed for all potential analytes currently identified in the tank farms (>240,000 chemicals).

Cartridge Test

1What is the scope of the cartridge testing? Are we testing for the entire list of Chemicals of Potential Concern (COPCs)?
The chemical cartridge testing will determine maximum service life and change out schedule for each cartridge, depending on the tank farm where it is being used. Tests are being conducted for all 61 COPCs.
2Are the samples for the cartridge testing going through the exhauster?
Yes, such as the AP exhauster. Other testing will be performed using the tank headspace. First tests were conducted in June 2016 at the AP Exhauster.
3Will our cartridge testing supersede manufacturer recommendations?
Our cartridge testing will supplement the manufacture recommendations and be specific to tank farm chemical constituents.


1What is the communication plan for the vapor effort?
Washington River Protection Solutions (WRPS) is committed to communicating with employees and stakeholders. Methods include the WRPS Safety intranet site, the hanfordvapors.com website, quarterly communications, Solutions articles, Tailgates, and Chemical Vapor Solutions Team (CVST) and CVST sub-team meetings.
2Will any of this information be out before controls are implemented?
There will be extensive communications prior to implementing changes in the field.


1What are the new/future engineering controls that we are putting in place?
The CVST Engineering sub-team is reviewing previously suggested engineering controls. These controls will be evaluated as part of Phase 2 of the Tank Vapor Assessment Team (TVAT) Implementation Plan.
2Are we planning any single-shell tank (SST) exhausters?
Yes, exhausters will be placed on SSTs planned for retrieval and closure (AX exhauster with A Farm to follow).
3Are we going to incorporate better filter material into the exhausters?
Engineering controls, such as filter materials, are being evaluated and may be recommendations as part of Phase 2. The Chief Technology Office (CTO) is working with PNNL on these materials.


1Is characterization of headspace for double-shell tanks (DSTs) planned?
Yes, DSTs are included in the 20+ sampling evolutions for FY16.


1This plan sounds very much like the previous plan, how is this different? How are the workers going to be protected from exposure?
The TVAT Implementation Plan addresses each of the 47 TVAT recommendations with projects with dedicated cost, scope, resources, and management commitment. Results will be implemented regardless of who is managing the tank farms.
2How are we planning parity with RadCon for work planning documents?
The chemical ALARA guidance document will outline the process for incorporating chemical and vapor hazards into the work control process of the Integrated Safety Management System (ISMS).
3Why are we still using Vapor Control Zones (VCZs) in SST farms while workers are using SCBA?
VCZs are being evaluated as part of the respiratory protection evaluation.
4How can they be called fugitive emissions if they are coming from the tank?
Chemical vapors are called “fugitive emissions” when they are coming from unknown sources, not known sources, such as filtered vents. WRPS has an aggressive program to identify and/or correct fugitive emissions in the tank farms.


1Is there a better filter cartridge (combo chemical) that we can use?
Chemical cartridge evaluations are being conducted as part of the Phase 1 Vapor Project. Cartridges are undergoing field testing in AP tank farm.
2When is it predicted that tank farm workers will be taken off supplied air (SCBA)?
Tank farm workers will be required to wear SCBA until the control criteria has been met. Each tank farm will be evaluated separately with the appropriate respiratory protection for that farm determined.


1What is the progress on farm fugitive-emission source rounds & routines?
Mapping of 200-East area tank farms is completed with active routines in AP/A being completed at the current time. Work packages are being developed for identification of source locations for development of rounds and routines.
2How are we mapping fugitive-emission sources?
Industrial Hygiene is conducting readings and source sampling to identify source locations for rounds and routines. They are also using engineering information and drawings to help identify potential locations to search for fugitive emissions.


1How do we analyze for chemicals in the tanks that we don’t know about?
There are chemicals in the tanks that are at such low concentrations that it is difficult to test for them. WRPS is working with national laboratories to develop testing standards for these "trace" or Tentatively Identified Chemicals (TICs).
2Is all of the data that is being collected going into a database? Is it available to the workers?
Some recent industrial hygiene data is posted on the hanfordvapors.com website. All Industrial Hygiene data that is approved by procedure is collected is entered into a database. WRPS is working to make this data easily available to workers and stakeholders. The IH Vapor project team is conducting research and development with some equipment which will help evaluate the current characterization and determine a recommendation for the IH Program going forward for sampling.
3For training, we have Rad I/II. Will we have something similar for chemicals?
We are looking into expanding Chemical Hazards Awareness Training (CHAT) training into a CHEM I/II type training where CHEM I would be for general employees and CHEM II would be for those working in the Tank Farms. General awareness training is being evaluated to determine if updates to the Hanford General Employee Training (HGET) are needed. An update to CHAT has been conducted and is currently under evaluation.

Q&A Issue #2

This is an in-progress document providing answers to employee questions. Q&As have been placed in general categories for ease of use. Answers may be updated as new information is developed or when evaluations of the item are completed.


1The status board showing workers the conditions in the tank farms is a good idea. Is it possible to use other types of outdoor displays to show wind speed/direction or other information, from inside the farm?
This may be evaluated as part of the pilot test for the Industrial Hygiene communication boards. Operations is conducting an evaluation of both audible and visual alerting systems for farm locations.
2Can we expand the communication boards to show status before workers enter the change trailers (such as flashing light, TV screens, etc.)?
This may be evaluated as part of the pilot for the IH communication boards.


1What improvements are leading to new engineered controls?
Evaluation of engineering controls is part of the TVAT Phase 1 Implementation Plan evaluation. Recommendations will be provided to senior management.
2Why don’t we install scrubbers or place chemical filters at the sources?
WRPS Engineering is evaluating engineering controls is part of the Phase 1 Implementation Plan. Recommendations will be provided to senior management.
3Is a powered filtration system being considered for the exhausters?
WRPS Engineering is evaluating engineering controls is part of the Phase 1 Implementation Plan. Recommendations will be provided to senior management.


1What is the turnaround time from Hanford’s 222-S Laboratory for the analysis of tank headspace samples?
It takes the 222-S Laboratory four weeks to process the headspace samples, analyze the samples and interpret the results.


1How far out does the dispersion modeling go (distance wise), and does it impact other contractors on site?
Currently, the dispersion modeling covers the 200 East site.
2Are we planning any testing for radio-tropic fungus within the tanks or systems?
Additional studies will be conducted as part of the Phase 2 Vapor Project after additional characterization studies have been conducted.
3Are we creating lessons learned during the vapor review process?
Yes, developing lessons learned is part of the pilot process within the scope of the Phase 1 vapor program.
4Are we fully funded by congress to implement the TVAT recommendations?
The Vapors Project has dedicated DOE funds committed to address the TVAT recommendations.
5Are we working on a correlation between weather changes, seasons and exposure events? If there is a correlation, can we watch the weather so it there is a likely situation for a vapor event we have IHTs ready?
The Phase 1 Vapor Project will evaluate possible correlations and make appropriate recommendations.
6Has DOE established the TVAT as a living document that stays with Tank Farms no matter who the contractor is?
Yes, improvements for the Tank Farms reside with DOE for the resolution of this issue.

Technical Evaluation

1Are we waiting for Phase II before putting the new equipment in the field?
New technologies have been deployed for pilot testing in A and AP farms. The equipment recommendations from Phase 1 will be reviewed and implemented in Phase 2.


1Are we saying that we are currently inadequate in our training and programs? If so why are we continuing to work?
WRPS has a world-class program and is enhancing current programs/training as new training and information becomes available. Using SCBA, workers are safe to continue to work using WRPS’ current work practices and plans.


1What are we going to do about sensitized workers or workers with allergies?
Additional studies will be conducted as part of the Phase 2 Vapor Project after additional characterization studies have been conducted.
2What does "taking care of the employee" mean?
WRPS is going to ensure that all affected employees receive the medical attention they need at HPMC or other medical providers.
3How would I know if I'm sensitized to chemical vapors?
This issue will be studied as part of the Phase 2 Vapor Project following conduct of additional vapors characterization studies.
4Health effects of the unknowns?
Studies have identified 1,800 chemicals in Hanford’s tanks. One of the purposes of the Phase 1 Vapor Project is to identify any additional chemical constituents in the tanks.
5What about chronic exposure that has not been documented (those who have never had any symptoms, but have had exposures for many years, then have symptoms)?
Additional studies will be conducted as part of the Phase 2 Vapor Project after additional characterization studies have been conducted.
6How are the workers covered if they never go to medical to be evaluated?
WRPS conducts Job Task Analyses for each of its employees. These “EJTAs” will be updated as new hazards are identified.
7Employee medical records may not be complete when dealing with exposure?
WRPS conducts Job Task Analyses for each of its employees. These “EJTAs” will be updated as new hazards are identified.