ASHRAE Newsletter Testing of Laboratory Chemical Hoods

ASHRAE 110 INFORMATIONAL NEWSLETTER #1

Testing of Laboratory Chemical Hoods

This newsletter is to help people understand the myths surrounding testing of containment devices, specifically Laboratory Chemical Hoods (a.k.a. Chemical Fume Hoods; or for our good friends in Europe and Canada, Fume Cupboards). Many people have reservations about performing a more thorough test or they may be confused on what testing options are available to them. Other people are apprehensive about the higher cost inherent in the tracer gas test procedure. This newsletter will answer some Frequently Asked Questions that many people may contemplate but haven’t asked, including:

How should my Laboratory Chemical Hoods be tested (i.e. What is required)?
Do I need the more rigorous ASHRAE 110 test?
What is Micro-Clean’s Laboratory Ventilation Management Plan and how can I implement it at little cost to me?
Why perform the ASHRAE 110 test at all?

1. How should my Laboratory Chemical Hoods be tested?

This is a very good question, and one that has plagued mankind since . . . . . well, since the late 1970’s when an alternate method of testing Chemical Hoods was introduced, one that went beyond a basic face velocity and smoke test. In 1985 the American Society of Heating, Refrigeration and Air conditioning Engineers turned a society funded research project (RP-70) into the 110th standard to come from their organization. They took the current Chemical Fume Hood testing standard-bearer at the time, SAMA (Scientific Apparatus Makers Association) LF10-1980, and added testing with an easily detectable gas, Freon, and several additional smoke tests. Also added was a test to measure the response time for a Variable Air Volume system. The tracer gas test was performed with a mannequin, simulating an operator standing at the face of the hood. Previous tests did not show leakage (from smoke) with anyone/anything blocking the airflow into the hood.

So what is required when testing Laboratory Chemical Hoods? The only requirement that must be followed regarding Laboratory Chemical Hood testing, coming from the federal government, is in OSHA’s (Occupational Safety and Health Administration) standard 29 CFR 1910.1450 – Occupational Exposures to Hazardous Chemicals in Laboratories. This standard, however, does not describe a method of testing, only that hoods be tested at least annually. OSHA mentions implementing a Chemical Hygiene Plan; a written program developed and implemented by the employer, which sets forth the procedures for testing (e.g. Standard Operating Procedures), equipment in use (Laboratory Chemical Hoods), any personal protective equipment needed while working at the hood and the work practices utilized while working at the hood. OSHA 29 CFR 1910.1450 (1)(c)(iii) states:

“A requirement that fume hoods and other protective equipment are functioning properly and specific measures that shall be taken to ensure proper and adequate performance of such equipment”

From this, the question can be raised: Is face velocity testing sufficient enough to meet the “requirement that fume hoods. . . are functioning properly?” Even a smoke test with a small tube/vial or dry ice dissipates quickly in air, can containment be visually guaranteed with the quick dissipation times? A tracer gas test can be quantitatively verified and should be repeatable.

Two common standards that discuss Laboratory Chemical Hood testing procedures (besides ASHRAE 110) are SEFA 1-2002 (Scientific Equipment and Furniture Association) and AIHA Z9.5-2003 (American Industrial Hygiene Association). These two, plus the ASHRAE 110 standard, are recommended practices, or guidelines, on testing a Laboratory Chemical Hood and their methods are no more mandatory that the ASHRAE 110 procedure. As stated above, the OSHA standard is very vague on test procedures. If one wants to know how to test a Chemical Hood they have several options. The most popular of which comes from one of the following recommended practices: SEFA 1-2002, ANSI/AIHA Z9.5-2003 & ANSI/ASHRAE 110-1995.

Prior to 2002, the SEFA 1.2 field evaluation test was taken directly from SAMA LF10-1980 and discussed a method of face velocity and smoke testing (outside the hood, at the face of the hood and around the side walls and equipment in the hood). In 1980 ASHRAE 110 wasn’t even a standard, a good reason why for many years face velocity and smoke testing was the only test method performed. Since 2002, SEFA and AIHA have updated their guidelines and have put more emphasis on the tracer gas testing outlined in the ASHRAE 110 standard. SEFA, which originally just copied SAMA LF10, has updated their standard to include references to the ASHRAE 110 standard in its’ three test modes, “As Manufactured”, “As Installed” and “As Used.” SEFA 1-2002, whose committee is comprised solely of Chemical Hood manufacturers, references the ASHRAE 110 test in its’ Section 5 of the standard discussing testing of a Chemical Hood when it is first installed in a facility. The air balancing must be completed before testing can be performed. SEFA 1-2002, section 5.3, states:

“It is recommended that hoods be tested in accordance with ASHRAE 110-1995 (or most current edition) before put into service”

It further states (also in 5.3):

“The ASHRAE 110 (test) is the recognized method for evaluating the performance of fume hoods.”

Lastly, the ANSI/AIHA Z9.5-2003 standard on Laboratory Ventilation talks about the entire laboratory system, not just the Chemical Hood. It discusses:
· exhaust stack discharge rates
· work practices for users
· preventative maintenance schedules for facilities
· test methods for the testing agency
· shows an example of a Laboratory Ventilation Management Plan
· discusses other containment devices
· addresses commissioning plans

Section 3.3.1 states why face velocity testing alone is inadequate:

“Factors including the design of the hood, the laboratory layout, and cross-drafts created by supply air and traffic all influence hood performance as much as or more than the face velocity.”

It goes on to state:

“An adequate face velocity is necessary but is not the only criterion to achieve acceptable performance and shall not be used as the only performance indicator.”

A study was performed a few years back that indicated approximately 17% of hoods tested using the ASHRAE 110 method had “acceptable” face velocities in the common range of 80-120 fpm, but “failed” the tracer gas containment test with recommended control levels exceeding 0.10 ppm, per ACGIH (American Conference of Governmental Industrial Hygienists) (Smith and Crooks, 1996). AIHA Z9.5 is very specific on newly installed or renovated hoods, stating:

“All newly installed, renovated or moved hoods shall be commissioned to ensure proper operation prior to use by laboratory personnel.”

2. Do I need the more rigorous ASHRAE 110 test?

The SEFA and AIHA standards on Laboratory Ventilation agree in semantics, both agree that the ASHRAE 110 tracer gas test is important. SEFA’s stance is that ASHRAE 110 testing is recommended when a hood is first installed, renovated or the Local Exhaust system is modified (i.e. fan belts changed, motor replaced, additional local exhaust devices added to a manifold system). AIHA’s stance is that ASHRAE 110 testing is required when a hood is first installed, renovated or modified.

Both standards agree that routine testing shall be conducted at least annually; they do not specify what type of testing to perform. ASHRAE 110 testing does not need to be performed at every annual interval, however it should be performed every few years as the operational process changes over time as the belts and bearings wear.

A very important feature of the ASHRAE 110 test that is not seen in a “basic” face velocity and smoke test is the Response Test on VAV systems. This determines how quickly the system responds to a change in sash elevation/opening. An additional test, the Sash Movement Effect Test, utilizing the tracer gas, determines if the system is containing as the sash is opened/closed. The “basic” tests do nothing to show containment in a dynamic condition, only static conditions, and proper use of a Laboratory Chemical Hood has the sash being lowered whenever the hood is not in use. So this brings up the question, Wouldn’t you want to know if the hood is containing properly as the sash is opened/closed?

The “As Installed” ASHRAE 110 test is performed before there is any equipment in the hood. This is a good reason to have the ASHRAE 110 test performed in an “As Used” condition.

Performing ASHRAE 110 tests annually on a facilities’ Chemical Hoods does not have to be a “break-the-bank” procedure. We realize ASHRAE 110 testing can be a major undertaking, which is why we work with our clients to install a cost effective Laboratory Ventilation Management Plan.

3. What is Micro-Clean’s Laboratory Ventilation Management Plan and how can I implement it at little cost to me?

Micro-Clean understands the desire of our clients and potential clients to have the most accurate, dependable, cost efficient testing performed on their hoods. The ASHRAE 110 test procedure takes about 3-4 times as long as a “basic” face velocity and smoke test. This is reflected in the higher cost to perform an ASHRAE 110 test. To offset the higher cost, Micro-Clean will work with the Chemical Hygiene Officer/Industrial Hygienist/Environmental Health & Safety in putting together a Laboratory Ventilation Management Plan that consists of cyclic ASHRAE 110/Basic testing.

Based on the number of units to be serviced annually, we can suggest a 3-, 4- or 5-year plan where ASHRAE 110 testing is performed on a number of hoods annually (33%, 25% or 20%) while performing the “basic” testing on the remainder of the Chemical Hoods. In doing this it is assured that the ASHRAE 110 test is performed on all hoods at least every 3, 4 or 5 years. A savings of over 50% can be realized by performing ASHRAE 110 testing on a percentage of hoods each year. Contact our sales department for a cost comparison model. We can develop a program that averages only a few dollars annually over “basic” testing alone.

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4. Why perform the ASHRAE 110 test at all?

The “basic” tests as outlined in the now defunct SAMA LF10 standard included face velocity testing and smoke testing at the sash opening. This was mirrored when SEFA 1.2 was introduced, and is performed (with modifications) to this day. So why is the ASHRAE 110 test needed? Here are ten compelling reasons why ASHRAE 110 testing should be performed:

1. Safety of the user is the utmost concern – why only perform a test that gives a potentially meaningless face velocity number (which says nothing about containment) and a smoke test that dissipates the smoke quickly in air (which may cause the tester to miss small leakage areas) when a test exists that shows how well a hood contains with a “body” at the face of the hood and gives repeatable results.
2. Quantitative vs. Qualitative – “basic” testing only gives qualitative information on containment under static conditions, ASHRAE 110 gives quantitative data through several tracer gas tests in both static and dynamic conditions
3. Dynamic testing is invaluable – the “basic” test does not show how well the hood contains when the sash is raised/lowered. ASHRAE 110 test has a dynamic Sash Movement Effect test which raises/lowers the sash while releasing tracer gas and monitoring the leakage
4. Litigations and lawsuits – with ASHRAE 110 the best test method available is being performed to create a safe working environment
5. Large smoke test gives better visualization of airflows within hood
6. Crossdraft test – smoke released outside hood to determine effect of turbulent airflows exterior to the Chemical Hood
7. Re-entrainment – exhausted gas coming back through supply air handler system will be noticed when performing ASHRAE 110 test
8. More realistic test with body (mannequin) at face of hood
9. Testing of VAV system performed during ASHRAE 110 test; not performed during “basic” test
10. More tests performed = more knowledge of hood containment abilities

This newsletter hopefully answered some questions that many people have been asking, but if it does not, feel free to request further information, or a clarification, on our web site, www.microcln.com. From our Home Page click on “Request Information”. At the bottom of the page is a section to write in your questions/comments. Our knowledgeable staff will be able to assist you with your inquiries. Also, if you would like to discuss implementing a Laboratory Ventilation Management Plan feel free to contact our sales team, or leave your question on our website under the “Request Information” page (from Micro-Clean’s Home Page).

Back to Top

NEXT NEWSLETTER

Our next ASHRAE 110 Informational Newsletter will show the results of a year-long study of approximately 1700 ASHRAE 110 tests, it will show the percentage of Laboratory Chemical Hoods that passed a face velocity test and local smoke study (i.e. small volume smoke output) but failed a tracer gas test or large volume smoke study. Why is this number important? It shows the percentage of hoods that pass a “basic” test but actually have leakage, in some cases gross leakage, in the breathing zone on an operator.

	Providing Cleanroom Certification, ASHRAE 110 Testing, Calibration, Decontamination, USP 797 Solutions, Compressed Air Line Testing, Environmental Monitoring and Qualification Services


How should my Laboratory Chemical Hoods be tested (i.e. What is required)? Do I need the more rigorous ASHRAE 110 test? What is Micro-Clean’s Laboratory Ventilation Management Plan and how can I implement it at little cost to me? Why perform the ASHRAE 110 test at all? Next Newsletter Request Information Also see our other Web pages on Laboratory Ventilation and ASHRAE 110 Testing A savings of over 50% can be realized by performing ASHRAE 110 testing on a percentage of hoods each year.	ASHRAE 110 INFORMATIONAL NEWSLETTER #1 Testing of Laboratory Chemical Hoods This newsletter is to help people understand the myths surrounding testing of containment devices, specifically Laboratory Chemical Hoods (a.k.a. Chemical Fume Hoods; or for our good friends in Europe and Canada, Fume Cupboards). Many people have reservations about performing a more thorough test or they may be confused on what testing options are available to them. Other people are apprehensive about the higher cost inherent in the tracer gas test procedure. This newsletter will answer some Frequently Asked Questions that many people may contemplate but haven’t asked, including: How should my Laboratory Chemical Hoods be tested (i.e. What is required)? Do I need the more rigorous ASHRAE 110 test? What is Micro-Clean’s Laboratory Ventilation Management Plan and how can I implement it at little cost to me? Why perform the ASHRAE 110 test at all? 1. How should my Laboratory Chemical Hoods be tested? This is a very good question, and one that has plagued mankind since . . . . . well, since the late 1970’s when an alternate method of testing Chemical Hoods was introduced, one that went beyond a basic face velocity and smoke test. In 1985 the American Society of Heating, Refrigeration and Air conditioning Engineers turned a society funded research project (RP-70) into the 110th standard to come from their organization. They took the current Chemical Fume Hood testing standard-bearer at the time, SAMA (Scientific Apparatus Makers Association) LF10-1980, and added testing with an easily detectable gas, Freon, and several additional smoke tests. Also added was a test to measure the response time for a Variable Air Volume system. The tracer gas test was performed with a mannequin, simulating an operator standing at the face of the hood. Previous tests did not show leakage (from smoke) with anyone/anything blocking the airflow into the hood. So what is required when testing Laboratory Chemical Hoods? The only requirement that must be followed regarding Laboratory Chemical Hood testing, coming from the federal government, is in OSHA’s (Occupational Safety and Health Administration) standard 29 CFR 1910.1450 – Occupational Exposures to Hazardous Chemicals in Laboratories. This standard, however, does not describe a method of testing, only that hoods be tested at least annually. OSHA mentions implementing a Chemical Hygiene Plan; a written program developed and implemented by the employer, which sets forth the procedures for testing (e.g. Standard Operating Procedures), equipment in use (Laboratory Chemical Hoods), any personal protective equipment needed while working at the hood and the work practices utilized while working at the hood. OSHA 29 CFR 1910.1450 (1)(c)(iii) states: “A requirement that fume hoods and other protective equipment are functioning properly and specific measures that shall be taken to ensure proper and adequate performance of such equipment” From this, the question can be raised: Is face velocity testing sufficient enough to meet the “requirement that fume hoods. . . are functioning properly?” Even a smoke test with a small tube/vial or dry ice dissipates quickly in air, can containment be visually guaranteed with the quick dissipation times? A tracer gas test can be quantitatively verified and should be repeatable. Two common standards that discuss Laboratory Chemical Hood testing procedures (besides ASHRAE 110) are SEFA 1-2002 (Scientific Equipment and Furniture Association) and AIHA Z9.5-2003 (American Industrial Hygiene Association). These two, plus the ASHRAE 110 standard, are recommended practices, or guidelines, on testing a Laboratory Chemical Hood and their methods are no more mandatory that the ASHRAE 110 procedure. As stated above, the OSHA standard is very vague on test procedures. If one wants to know how to test a Chemical Hood they have several options. The most popular of which comes from one of the following recommended practices: SEFA 1-2002, ANSI/AIHA Z9.5-2003 & ANSI/ASHRAE 110-1995. Prior to 2002, the SEFA 1.2 field evaluation test was taken directly from SAMA LF10-1980 and discussed a method of face velocity and smoke testing (outside the hood, at the face of the hood and around the side walls and equipment in the hood). In 1980 ASHRAE 110 wasn’t even a standard, a good reason why for many years face velocity and smoke testing was the only test method performed. Since 2002, SEFA and AIHA have updated their guidelines and have put more emphasis on the tracer gas testing outlined in the ASHRAE 110 standard. SEFA, which originally just copied SAMA LF10, has updated their standard to include references to the ASHRAE 110 standard in its’ three test modes, “As Manufactured”, “As Installed” and “As Used.” SEFA 1-2002, whose committee is comprised solely of Chemical Hood manufacturers, references the ASHRAE 110 test in its’ Section 5 of the standard discussing testing of a Chemical Hood when it is first installed in a facility. The air balancing must be completed before testing can be performed. SEFA 1-2002, section 5.3, states: “It is recommended that hoods be tested in accordance with ASHRAE 110-1995 (or most current edition) before put into service” It further states (also in 5.3): “The ASHRAE 110 (test) is the recognized method for evaluating the performance of fume hoods.” Lastly, the ANSI/AIHA Z9.5-2003 standard on Laboratory Ventilation talks about the entire laboratory system, not just the Chemical Hood. It discusses: · exhaust stack discharge rates · work practices for users · preventative maintenance schedules for facilities · test methods for the testing agency · shows an example of a Laboratory Ventilation Management Plan · discusses other containment devices · addresses commissioning plans Section 3.3.1 states why face velocity testing alone is inadequate: “Factors including the design of the hood, the laboratory layout, and cross-drafts created by supply air and traffic all influence hood performance as much as or more than the face velocity.” It goes on to state: “An adequate face velocity is necessary but is not the only criterion to achieve acceptable performance and shall not be used as the only performance indicator.” A study was performed a few years back that indicated approximately 17% of hoods tested using the ASHRAE 110 method had “acceptable” face velocities in the common range of 80-120 fpm, but “failed” the tracer gas containment test with recommended control levels exceeding 0.10 ppm, per ACGIH (American Conference of Governmental Industrial Hygienists) (Smith and Crooks, 1996). AIHA Z9.5 is very specific on newly installed or renovated hoods, stating: “All newly installed, renovated or moved hoods shall be commissioned to ensure proper operation prior to use by laboratory personnel.” Back to Top 2. Do I need the more rigorous ASHRAE 110 test? The SEFA and AIHA standards on Laboratory Ventilation agree in semantics, both agree that the ASHRAE 110 tracer gas test is important. SEFA’s stance is that ASHRAE 110 testing is recommended when a hood is first installed, renovated or the Local Exhaust system is modified (i.e. fan belts changed, motor replaced, additional local exhaust devices added to a manifold system). AIHA’s stance is that ASHRAE 110 testing is required when a hood is first installed, renovated or modified. Both standards agree that routine testing shall be conducted at least annually; they do not specify what type of testing to perform. ASHRAE 110 testing does not need to be performed at every annual interval, however it should be performed every few years as the operational process changes over time as the belts and bearings wear. A very important feature of the ASHRAE 110 test that is not seen in a “basic” face velocity and smoke test is the Response Test on VAV systems. This determines how quickly the system responds to a change in sash elevation/opening. An additional test, the Sash Movement Effect Test, utilizing the tracer gas, determines if the system is containing as the sash is opened/closed. The “basic” tests do nothing to show containment in a dynamic condition, only static conditions, and proper use of a Laboratory Chemical Hood has the sash being lowered whenever the hood is not in use. So this brings up the question, Wouldn’t you want to know if the hood is containing properly as the sash is opened/closed? The “As Installed” ASHRAE 110 test is performed before there is any equipment in the hood. This is a good reason to have the ASHRAE 110 test performed in an “As Used” condition. Performing ASHRAE 110 tests annually on a facilities’ Chemical Hoods does not have to be a “break-the-bank” procedure. We realize ASHRAE 110 testing can be a major undertaking, which is why we work with our clients to install a cost effective Laboratory Ventilation Management Plan. Back to Top 3. What is Micro-Clean’s Laboratory Ventilation Management Plan and how can I implement it at little cost to me? Micro-Clean understands the desire of our clients and potential clients to have the most accurate, dependable, cost efficient testing performed on their hoods. The ASHRAE 110 test procedure takes about 3-4 times as long as a “basic” face velocity and smoke test. This is reflected in the higher cost to perform an ASHRAE 110 test. To offset the higher cost, Micro-Clean will work with the Chemical Hygiene Officer/Industrial Hygienist/Environmental Health & Safety in putting together a Laboratory Ventilation Management Plan that consists of cyclic ASHRAE 110/Basic testing. Based on the number of units to be serviced annually, we can suggest a 3-, 4- or 5-year plan where ASHRAE 110 testing is performed on a number of hoods annually (33%, 25% or 20%) while performing the “basic” testing on the remainder of the Chemical Hoods. In doing this it is assured that the ASHRAE 110 test is performed on all hoods at least every 3, 4 or 5 years. A savings of over 50% can be realized by performing ASHRAE 110 testing on a percentage of hoods each year. Contact our sales department for a cost comparison model. We can develop a program that averages only a few dollars annually over “basic” testing alone. Back to Top 4. Why perform the ASHRAE 110 test at all? The “basic” tests as outlined in the now defunct SAMA LF10 standard included face velocity testing and smoke testing at the sash opening. This was mirrored when SEFA 1.2 was introduced, and is performed (with modifications) to this day. So why is the ASHRAE 110 test needed? Here are ten compelling reasons why ASHRAE 110 testing should be performed: 1. Safety of the user is the utmost concern – why only perform a test that gives a potentially meaningless face velocity number (which says nothing about containment) and a smoke test that dissipates the smoke quickly in air (which may cause the tester to miss small leakage areas) when a test exists that shows how well a hood contains with a “body” at the face of the hood and gives repeatable results. 2. Quantitative vs. Qualitative – “basic” testing only gives qualitative information on containment under static conditions, ASHRAE 110 gives quantitative data through several tracer gas tests in both static and dynamic conditions 3. Dynamic testing is invaluable – the “basic” test does not show how well the hood contains when the sash is raised/lowered. ASHRAE 110 test has a dynamic Sash Movement Effect test which raises/lowers the sash while releasing tracer gas and monitoring the leakage 4. Litigations and lawsuits – with ASHRAE 110 the best test method available is being performed to create a safe working environment 5. Large smoke test gives better visualization of airflows within hood 6. Crossdraft test – smoke released outside hood to determine effect of turbulent airflows exterior to the Chemical Hood 7. Re-entrainment – exhausted gas coming back through supply air handler system will be noticed when performing ASHRAE 110 test 8. More realistic test with body (mannequin) at face of hood 9. Testing of VAV system performed during ASHRAE 110 test; not performed during “basic” test 10. More tests performed = more knowledge of hood containment abilities This newsletter hopefully answered some questions that many people have been asking, but if it does not, feel free to request further information, or a clarification, on our web site, www.microcln.com. From our Home Page click on “Request Information”. At the bottom of the page is a section to write in your questions/comments. Our knowledgeable staff will be able to assist you with your inquiries. Also, if you would like to discuss implementing a Laboratory Ventilation Management Plan feel free to contact our sales team, or leave your question on our website under the “Request Information” page (from Micro-Clean’s Home Page). Back to Top NEXT NEWSLETTER Our next ASHRAE 110 Informational Newsletter will show the results of a year-long study of approximately 1700 ASHRAE 110 tests, it will show the percentage of Laboratory Chemical Hoods that passed a face velocity test and local smoke study (i.e. small volume smoke output) but failed a tracer gas test or large volume smoke study. Why is this number important? It shows the percentage of hoods that pass a “basic” test but actually have leakage, in some cases gross leakage, in the breathing zone on an operator.
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Providing Cleanroom Certification, ASHRAE 110 Testing, Calibration, Decontamination, USP 797 Solutions, Compressed Air Line Testing, Environmental Monitoring and Qualification Services

ASHRAE 110 INFORMATIONAL NEWSLETTER #1

Testing of Laboratory Chemical Hoods

1. How should my Laboratory Chemical Hoods be tested?

2. Do I need the more rigorous ASHRAE 110 test?

Back to Top

4. Why perform the ASHRAE 110 test at all?

Back to Top

NEXT NEWSLETTER