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ChemDAQ, a manufacturer of ethylene oxide (EtO) monitoring systems, has posted a pdf of a comparison matrix on its website, pitting their systems against ours. Fair enough. We felt it only proper to reproduce their table, adding a fourth column with our comments. Since the tabular format is not...
For any gas to be detectable by an electrochemical sensor, it must first be "electroactive." As defined by the International Union of Pure and Applied Chemistry (IUPAC) Analytical Chemistry Division Commission on Electroanalytical Chemistry, an electroactive substance is... In voltammetry and...
Background In the continuing regulatory assault on ethylene oxide, more rules now apply. Fortunately, these latest statutes are not at all difficult to comply with. The new rule is called "National Emission Standards for Hospital Ethylene Oxide Sterilizers." It was published on 28 December 2007 as...
Written in response to a particular inquiry, this article is posted since it is of general interest. Calibration is a very important issue. One of Interscan's competitors recommends calibrating its EtO monitor with CO (Carbon Monoxide). There is nothing wrong with using CO to calibrate an analyzer,...
Badges are integrating rather than real-time devices, yielding an accumulated value—often incorrectly interpreted as an "average"—calculated over the time period the badge was active. The advantage of real time monitoring is that it WILL keep track of spikes and excursions, while a...
The original reference for periodic leak testing comes from 29 CFR 1910.1047 App A, and is entitled "Substance safety data sheet for ethylene oxide (non-mandatory)." Section VII-2-i of the document states: Leak detection. Sterilizer door gaskets, cylinder and vacuum piping, hoses, filters, and...
EPA and FIFRA While most matters regarding occupational exposure to toxic compounds—in the United States—fall under the purview of the Occupational Safety & Health Administration (OSHA), in some cases, other federal agencies are also involved. Under the Federal Insecticide, Fungicide,...
On 30 April 2009, OSHA released a comprehensive document entitled "Small Business Guide for Ethylene Oxide." This new publication is available as a spiffy pdf (14.2 MB) or as a more browsable web page. The agency considers it to be a "guidance document," in that it is advisory in nature, is...
Gas detection methods have been changing and evolving and awareness has heightened as well, along with the ever changing methods of sterilization. To answer your question regarding what "most" hospitals are using to monitor EtO, a fair response would be narrowed down to either electrochemical...
Sometimes, we are asked about the 0-50 ppm measuring range offered on our ethylene oxide (EtO) instruments. After all, a founding principle for direct-reading instruments, used in occupational health work, was that the range should be set up to cover one-tenth to 10 times the TLV-TWA, or as OSHA...
Hydrogen peroxide (H2O2 or simply "peroxide") has long been the subject of regulatory agency interest. The current allowable 8-hour time weighted average of 1 ppm dates back to 1992, if not earlier. The signs and symptoms of acute exposure to hydrogen peroxide include irritation of the eyes, nose,...
It should be noted that long before OSHA, and long before direct-reading instruments were available, people were doing toxic gas detection to protect their employees; combustible gas detection to protect their employees and their facilities; and, of course, they also did this to obtain lower...
This article is based on a request from Frank Denny, Director of the Office of Occupational Safety and Health of the United States Department of Veterans Affairs. During a recent conversation, Mr. Denny had indicated that two of the most frequently asked questions to personnel in his office...
Background In the continuing regulatory assault on ethylene oxide, more rules now apply. Fortunately, these latest statutes are not at all difficult to comply with. The new rule is called "National Emission Standards for Hospital Ethylene Oxide Sterilizers." It was published on 28 December 2007 as...
Virtually every industrial facility has some kind of gas detection in place: Millions of portable units are in service, and at least a million points of continuous gas detection have been deployed. However, what is being done with all the data? The first and most vital use of this data, of course,...
Background Gas detection instruments must often be used or installed in areas considered to be "hazardous locations." Generically, all sorts of hazards might be recognized in a particular environment, but the term "hazardous locations," as it applies to electrically-operated equipment refers to...
The original reference for periodic leak testing comes from 29 CFR 1910.1047 App A, and is entitled "Substance safety data sheet for ethylene oxide (non-mandatory)." Section VII-2-i of the document states: Leak detection. Sterilizer door gaskets, cylinder and vacuum piping, hoses, filters, and...
There are two classic aspects of toxic gas detection— a) Monitoring normal employee exposure, to determine if regulatory levels have been exceeded in the long-term b) Monitoring to warn of hazardous levels that might occur in the short term Of course, both of these functions can be...
With the advent, in 2005, of a practical ozone-based sterilizer by TSO3, Inc. (Model 125L), and its subsequent installation into sterile processing facilities, ChemDAQ added ozone monitoring to its product line. Need we mention that Interscan has offered ozone monitoring instruments for...
While guidelines may exist that mandate monitoring of an area for any number of toxic compounds, no official government recommendations are made as to the detailed design of such a monitoring system. In practice, the design of a toxic gas area monitoring system results from a collaboration between...
EPA and FIFRA While most matters regarding occupational exposure to toxic compounds—in the United States—fall under the purview of the Occupational Safety & Health Administration (OSHA), in some cases, other federal agencies are also involved. Under the Federal Insecticide, Fungicide,...
On 30 April 2009, OSHA released a comprehensive document entitled "Small Business Guide for Ethylene Oxide." This new publication is available as a spiffy pdf (14.2 MB) or as a more browsable web page. The agency considers it to be a "guidance document," in that it is advisory in nature, is...
EPA's Method 21, entitled "Determination Of Volatile Organic Compound Leaks," calls for a portable instrument to be used for this purpose, and details certain specifications and calibration requirements. "Volatile Organic Compounds," better known as VOC's, have been defined by EPA to include in...
As landlord for the civilian federal government, the Public Buildings Service—a principal division of the General Services Administration (GSA)—owns and leases over 354 million square feet of space in 8,600 buildings in more than 2,200 communities nationwide. For several years, the GSA...
Most codes and standards—at least regarding allowable concentrations of various substances—are promulgated by domestic jurisdictions, whether at the state/province or national governmental level. However, there are numerous international organizations that publish recommendations on...
Note: All exposure limits cited in this article are current as of 31 December 2006 Ultimately, the entire matter of where to set the instantaneous concentration alarm(s) is tied into what is expected by the regulatory agency. In the United States, for most workplace...
Ever since Interscan developed a portable hydrazine analyzer for Brooks Air Force Base, way back in the late 1970's, our instruments have been widely deployed in all facets of hypergol (pertaining to fluid propellant) fuel and oxidizer measurements. A new wrinkle was brought in when NASA requested...
For any gas to be detectable by an electrochemical sensor, it must first be "electroactive." As defined by the International Union of Pure and Applied Chemistry (IUPAC) Analytical Chemistry Division Commission on Electroanalytical Chemistry, an electroactive substance is... In voltammetry and...
It should be noted that long before OSHA, and long before direct-reading instruments were available, people were doing toxic gas detection to protect their employees; combustible gas detection to protect their employees and their facilities; and, of course, they also did this to obtain lower...
This article is based on a request from Frank Denny, Director of the Office of Occupational Safety and Health of the United States Department of Veterans Affairs. During a recent conversation, Mr. Denny had indicated that two of the most frequently asked questions to personnel in his office...
Thanks for your question. The answer depends on what you mean by "double," and even on how we define "detector." Usually, "detector" means the sensing element within the instrument. But, people sometimes refer to the entire instrument as the detector. Now, if the sensor for carbon monoxide also...
First, let's define the terms: "Continuous" monitoring means that each sampling point is being monitored all the time, and in most cases, the concentration displayed reflects what is truly happening at the point in real time. There are certain exceptions to this involving instrument techniques...
A detector tube is a graduated glass tube filled with a chemical reagent that will produce a color change, when exposed to the gas in question. It is used with a hand pump that will draw a sample into the tube. The tubes are generally supplied in packages of ten, and are sealed at both ends. In...
Badges are integrating rather than real-time devices, yielding an accumulated value—often incorrectly interpreted as an "average"—calculated over the time period the badge was active. The advantage of real time monitoring is that it WILL keep track of spikes and excursions, while a...
While guidelines may exist that mandate monitoring of an area for any number of toxic compounds, no official government recommendations are made as to the detailed design of such a monitoring system. In practice, the design of a toxic gas area monitoring system results from a collaboration between...
Very simply, since no two toxic gas detection applications are the same. We admit that this concept has been obscured under the quite false rubric that "All gas detection is confined entry." Certainly, a goodly percentage of all portable gas detection instruments are designed as if they are...
Note: All exposure limits cited in this article are current as of 31 December 2006 Ultimately, the entire matter of where to set the instantaneous concentration alarm(s) is tied into what is expected by the regulatory agency. In the United States, for most workplace...
NOTE: This application was cited in the last section of another Knowledge Base article, and is also referred to here. A large, enclosed, arena-like structure is used for testing heavy construction vehicles. The facility has high ceilings [>50 feet (15.2 m)] to accommodate the large vehicles....
Ever since Interscan developed a portable hydrazine analyzer for Brooks Air Force Base, way back in the late 1970's, our instruments have been widely deployed in all facets of hypergol (pertaining to fluid propellant) fuel and oxidizer measurements. A new wrinkle was brought in when NASA requested...
EPA's Method 21, entitled "Determination Of Volatile Organic Compound Leaks," calls for a portable instrument to be used for this purpose, and details certain specifications and calibration requirements. "Volatile Organic Compounds," better known as VOC's, have been defined by EPA to include in...
Following the active hurricane seasons of 2004 and 2005, there was an upsurge in home construction. Demand for drywall exceeded the domestic supply, and a certain amount of drywall was imported from China. In June, 2008, the State of Florida's Department of Health received its first call from a...
As landlord for the civilian federal government, the Public Buildings Service—a principal division of the General Services Administration (GSA)—owns and leases over 354 million square feet of space in 8,600 buildings in more than 2,200 communities nationwide. For several years, the GSA...
Hydrogen peroxide (H2O2 or simply "peroxide") has long been the subject of regulatory agency interest. The current allowable 8-hour time weighted average of 1 ppm dates back to 1992, if not earlier. The signs and symptoms of acute exposure to hydrogen peroxide include irritation of the eyes, nose,...
There are two classic aspects of toxic gas detection— a) Monitoring normal employee exposure, to determine if regulatory levels have been exceeded in the long-term b) Monitoring to warn of hazardous levels that might occur in the short term Of course, both of these functions can be...
For some time, ChemDAQ has been touting its capability of monitoring hydrogen peroxide, in addition to its original EtO product line. As you may be aware, Interscan also offers hydrogen peroxide monitoring instrumentation, and—unlike ChemDAQ—our line includes portable analyzers, as...
ChemDAQ, a manufacturer of ethylene oxide (EtO) monitoring systems, has posted a pdf of a comparison matrix on its website, pitting their systems against ours. Fair enough. We felt it only proper to reproduce their table, adding a fourth column with our comments. Since the tabular format is not...
Thanks for your question. The answer depends on what you mean by "double," and even on how we define "detector." Usually, "detector" means the sensing element within the instrument. But, people sometimes refer to the entire instrument as the detector. Now, if the sensor for carbon monoxide also...
First, let's define the terms: "Continuous" monitoring means that each sampling point is being monitored all the time, and in most cases, the concentration displayed reflects what is truly happening at the point in real time. There are certain exceptions to this involving instrument techniques...
Gas detection methods have been changing and evolving and awareness has heightened as well, along with the ever changing methods of sterilization. To answer your question regarding what "most" hospitals are using to monitor EtO, a fair response would be narrowed down to either electrochemical...
Definitions A sample draw system uses a pump to draw sample back into the instrument, where it enters the sensor for analysis, and is then exhausted to the atmosphere or vent line. Gas detection instruments with diffusion sensors do not use a pump to pull the sample to the sensor. Instead, they...
Very simply, since no two toxic gas detection applications are the same. We admit that this concept has been obscured under the quite false rubric that "All gas detection is confined entry." Certainly, a goodly percentage of all portable gas detection instruments are designed as if they are...
Virtually every industrial facility has some kind of gas detection in place: Millions of portable units are in service, and at least a million points of continuous gas detection have been deployed. However, what is being done with all the data? The first and most vital use of this data, of course,...
When a gas concentration is measured or reported, we may talk in terms of ppm, but in reality we are measuring the partial pressure of the gas. (Refer to Dalton's Law of Partial Pressures) Thus, any instrument reading is going to be affected by changes in ambient pressure. It is necessary to...
"Dew Point" is defined as the temperature to which a given volume of air must be cooled at constant pressure and constant water vapor content in order for saturation to occur. If the air is cooled further, some of the moisture will condense. The notion of "Saturated Vapor Pressure" can be...
Go directly to conversion calculators Early on, in our first chemistry classes, we learn about solutions, and different ways of expressing their concentrations. Since a solution is any homogeneous mixture of two or more substances, gas mixtures are indeed solutions. In the world of gas detection,...
Definitions"Accuracy" as defined in the ANSI/ISA—51.1—1979 (R1993) standard Process Instrumentation Terminology is:[T]he degree of conformity of an indicated value to a recognized accepted standard value, or ideal value.Two common methods of rating or expressing accuracy are: As a percent of...
"Minimum Detectability" is one of those instrumentation terms that is used frequently, but is seldom defined. Indeed, even though you will encounter this term on many data sheets, its definition does not appear in any of the usual learned references, including Process Instrumentation Terminology,...
Interscan provides detailed sensor response data in our Tech Center. Rise time to 90% of final value, rise time to 50% of final value, and fall time to 10% of original value are given for all gases, and specialized sensor types for hydrazine and hydrogen sulfide. It is noted there that the 50%...
Introduction It is quite unlikely that you will ever use an absolute method for gas detection. Rather, you will employ any one of dozens of "relative" [or "reference," but not necessarily EPA Reference] methods—that is, methods that produce some output that must be calibrated against a known...
The answer to your question is YES. You are correct in noting that the response of our instruments is linear. More than that, electrochemical voltametric sensors (such as we use) are inherently linear, with no electronic compensation required. However, for optimum accuracy in most applications,...
Written in response to a particular inquiry, this article is posted since it is of general interest. Calibration is a very important issue. One of Interscan's competitors recommends calibrating its EtO monitor with CO (Carbon Monoxide). There is nothing wrong with using CO to calibrate an analyzer,...
As you may know, surrogate gas calibration for chlorine dioxide is recommended because it is extremely difficult to generate a stable source of ClO2, especially for practical field use. Indeed, the use of chlorine as a surrogate for chlorine dioxide calibration is one of the very few instances...
As discussed in the Calibration Basics Knowledge Base article, Interscan's gas analyzers, and virtually all other direct-reading gas analyzers are not absolute methods. Rather, they employ "relative" [or "reference," but not necessarily EPA Reference] methods. That is, methods that produce some...
The term "surrogate calibration" refers to a practice in instrument calibration whereby a standard different from the entity to be measured is utilized. For example, thermal flowmeters are based on convective heat transfer effects, and can be calibrated at ambient conditions on a specific gas, and...
See our article entitled "Calibration Basics." For ammonia, we would recommend permeation tubes.
Background Gas detection instruments must often be used or installed in areas considered to be "hazardous locations." Generically, all sorts of hazards might be recognized in a particular environment, but the term "hazardous locations," as it applies to electrically-operated equipment refers to...
In the wake of the FEMA trailers and the recalled toys from China—to say nothing of the hype surrounding the Consumer Product Safety Improvement Act of 2008 (CPSIA)—you may have heard some pundit say that "There is no safe level of (fill in the name of your favorite toxic substance)."...
The dictionary defines "danger" as "the state of being exposed to harm : liability to injury, pain, or loss." Typically, gas detection is deployed in areas that contain potential danger. This danger may result from some sort of upset condition, as in a leak—representing an immediate toxic or...
This is a follow-up to our earlier article on Using Common Sense and Science in Expressing Gas Concentrations, inspired by a real-life adventure of one of our sales engineers. As our hero was slogging through some e-mail inquiries, he came upon two units of measurement he had not seen...
Go directly to conversion calculators Early on, in our first chemistry classes, we learn about solutions, and different ways of expressing their concentrations. Since a solution is any homogeneous mixture of two or more substances, gas mixtures are indeed solutions. In the world of gas detection,...
As if it weren't bad enough that clueless environmental authorities try to impose their ignorance on the field by using so-called "metric" units of gas concentration, another trap may be lurking for you. Everyone around the world agrees that a part-per-million (ppm) equals 10-6. Unfortunately,...
Definitions"Accuracy" as defined in the ANSI/ISA—51.1—1979 (R1993) standard Process Instrumentation Terminology is:[T]he degree of conformity of an indicated value to a recognized accepted standard value, or ideal value.Two common methods of rating or expressing accuracy are: As a percent of...
In many cases, the terms "gas detector" and "gas monitor" are used interchangeably, and this can lead to confusion. When the word "detector" is mentioned in the context of a detector tube, it is clear that we are referring to short term or even one-shot grab sample measurements. Moreover, when...
"Minimum Detectability" is one of those instrumentation terms that is used frequently, but is seldom defined. Indeed, even though you will encounter this term on many data sheets, its definition does not appear in any of the usual learned references, including Process Instrumentation Terminology,...
Interscan provides detailed sensor response data in our Tech Center. Rise time to 90% of final value, rise time to 50% of final value, and fall time to 10% of original value are given for all gases, and specialized sensor types for hydrazine and hydrogen sulfide. It is noted there that the 50%...
As if it weren't bad enough that clueless environmental authorities try to impose their ignorance on the field by using so-called "metric" units of gas concentration, another trap may be lurking for you. Everyone around the world agrees that a part-per-million (ppm) equals 10-6. Unfortunately,...