Record of Communication

Subject: Logistics for Cylinder Analysis

On December 7, 2009, Lyn Gameson of the National Institute of Standards and Technology

(NIST) responded to an inquiry from John Schakenbach of the Environmental Protection Agency

(EPA) regarding Protocol Gas Verification Program (PGVP) logistics that would allow accurate, 

low cost, and fast cylinder analysis.

EPA Assumptions:

a.) We believe there are approximately 14 specialty gas companies that market EPA Protocol 

gases; some of these companies have multiple production sites. We estimate there are about 30 

EPA Protocol gas production sites in the U.S.

b.) Each of these production sites would enter into an agreement with NIST each year to analyze 

cylinders and produce and send to EPA reports and to determine whether the certification label 

accompanying each cylinder meets the requirements of the Traceability Protocol for up to 4

cylinders from each production site, for a total of 120 cylinders.

c.) Therefore, in less than one year, each year, NIST would need to analyze and produce and 

send to EPA reports for up to 120 cylinders, and determine whether the certification label 

accompanying each cylinder meets the requirements of the Traceability Protocol.

d.) EPA (through our contractor) would send NIST 6 batches of 20 cylinders each. Each batch 

would have cylinders of similar composition and concentration.

EPA Questions:

- Is 20 cylinders per batch optimum for you?

- How long should we wait between batch shipments?

- Assuming the appropriate interval between batches, how long would it take NIST to complete 

all of the tasks in b.) above for all 120 cylinders?

- Can cylinder batches arrive at NIST and can analysis start at any time during the year?

NIST Assumptions:

a) All audit cylinders will be purchased by the contractor and stored by them.

b) We will be sent a list of the cylinders purchased, including copies of the vendor 

Certificates of Analysis.

c) We will inform the contractor what cylinders to ship and when - most probably in batches 

of 20 cylinders of the same range.

d) The audit gas mixtures will be in three ranges, currently:
2

High: CO2 at 20%; NO at 900 ppm; SO2 at 1000 ppm

Mid: CO2 at 12%; NO at 400 ppm; SO2 at 500 ppm

Low: CO2 at 5%; NO at 50 ppm; SO2 at 50 ppm

e) We understand that the gas mixture compositions may change in the future. If the 

following hold true for future changes, then there will be little or no impact on our schedule:

e1) No more than three gas mixture ranges

e2) The concentration for each component falls under the following ranges:

CO: 2 - 20%

NO: 50 - 1000 ppm

SO2: 50 - 1000 ppm

If future changes fall outside these assumptions, then we need to be informed as soon as possible 

so that we can discuss the impact on our schedule (and costs).

f) No impurity (including NOx) analysis is required.

NIST Answers:

If the above assumptions hold, then the answers are:

Question: Is 20 cylinders per batch optimum for you?

Answer: Yes.

Question: How long should we wait between batch shipments?

Answer: As per our instructions / schedule. Typically, two weeks.

Question: Assuming the appropriate interval between batches, how long would it take NIST to 

complete all of the tasks in b.) above for all 120 cylinders?

Answer: Six months (including report write up) - maximum.

Question: Can cylinder batches arrive at NIST and can analysis start at any time during the 

year?

Answer: As per our instructions / schedule. We are planning to be in position to take delivery of 

the first batch in early February.