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Carbon Dioxide CO2 Limits & Exposure FAQs Q&A about CO2 exposure effects & calculations
POST a QUESTION or COMMENT about Carbon Dioxide CO2 gas levels indoors, CO2outside, CO2testing, CO2poisoning symptoms, & CO2 exposure limits and toxicity for humans
Carbon Dioxide CO2 Exposure Limits & Toxicity to humans:
This article series discusses normal and abnormal CO2 gas levels, the toxicity and exposure limits for exposure to carbon dioxide gas (CO2). We discuss Carbon Dioxide gas levels in outdoor air, in buildings, typical CO2 levels and conditions under which levels are unsafe.
We discuss the symptoms of carbon dioxide poisoning, describe different types of risks where high levels of CO2 may be present, and present data about the effects of CO2 exposure. Seek prompt advice from your doctor or health/safety experts if you have any reason to be concerned about exposure to toxic gases. Links on this page also direct the reader to carbon monoxide gas information in a separate document.
We give references and explanation regarding toxicity of Carbon Dioxide. Links on this page also direct the reader to carbon monoxide gas information in a separate document.
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Q&A about Hazards & Concentrations of Carbon Dioxide - CO2 in Air
These questions & answers about carbon dioxide levels, hazards, and calculations were posted originally at CARBON DIOXIDE - CO2 - topic home - be sure to review that information.
Question:
progression of CO2 in the body at high levels
progression of high Carbon Dioxide in your body when it is 2% over the normal? / at what level do you do to STOP the the progression when it is 2% - E. Avery 7/23/2011
Reply:
unclear;
Question: where to place equipment to measure CO2 from a generator?
what is the distance i can plce the equipment in other to measure accurate reading of c02 emissions from a generator. - Afolabi 12/19/2011
Reply:
Afolabi
I'm sorry but I can't quite see how to answer your question. A "generator" ??
The sensitivity and design-operating range of different types of gas detection equipment vary widely.
For example a ceiling mounted home carbon monoxide detector is intended to be placed at a variety of locations in a home, some many rooms away from the most likely CO source. But other test equipment may require distances ranging from centimeters to many meters.
Our TIF 8800, for example, has a sensitivity adjustment. So without consulting the equipment instructions, there is no right answer to your question. And you scare us - let's hope no one's safety is relying on your approach.
Question: What is the math around PELS?
This article is interesting. I think I understand the concept but I have an application that use an analyzer.
To calibrate this instrument, I need to use an 8% SO2 compress gas cylinder (cylinder capacity 5m3). This is located in a sealed 10x10x10 room, so my room is 1000m3 and unventilated.
Worst case scenario, the cylinder empties in this room. Is this an accute risk knowing that 3000 ppm is the LC50 (1/2hour) limit and the bottle contains 80000ppm? I have a bit of difficulties to put some math around this. Could you please explain?
I think 8% concentration x 5m3 cylinder = 0.4m3 of SO2 release in the room.
The gas will occupy 0.4m3/1000m3 = 0.04% of the room volume which is 400ppm.
400ppm < LC50 3000ppm = Low Risk?
- Syl 4/4/2-12
Reply:
Syl, your question was a bit unclear and makes me worry that you are messing with gases without proper education or preparation. You are asking about Sulphur dioxide (SO2) in an article about Carbon dioxide (CO2) - in any event, if you are asking about recommended exposure limits for Sulphur dioxide SO2,
depending on the standard, SO2 PELs range among 0.25 ppm, 2 ppm, or 5 ppm.
please see details at
GAS EXPOSURE EFFECTS, TOXIC where below that title you'll see a link for Sulfur Dioxide Gas
those article links are at page top
Reader followup:
Dan, I can assure you that nobody will be put in danger. Proper assessment will be done by qualified people for installation certification. Let me reformulate my question. I am interested to know how we determine if an area could be potentially dangerous or not. I mentioned SO2 but we can do it with CO2 if you like. The math behind is what I am looking for.
Let's say for instance that a 5m3 gas cylinder containing 2000 ppm of CO2 is totally released in a 1000m3 closed room. What would be the indication of a gas detector located in the room, assuming the gas occupy the whole area due to an internal air movement (I understand that some area can have a higher concentration than other depending of the gas properties). I don’t think that a meter would read 1000ppm of CO2 because it is diluted in the air. What would be the reading in the middle of the room?
Question: are there carbon dioxide hazards in the Space Station?
Why the health problems in space station reported by NASA long ago---at 500 ppm CO2 ? - Ron Schmoller 8/5/2012
Reply:
Ron, if you can give us a citation, article, document source I'd be glad to take a look. A Google Scholar search for "Carbon dioxide hazards in the space station" didn't return a single article that addressed your question.
Question: question about CO Carbon Monoxide ... let's not confuse CO with CO2
can a person whose had serious exposure to carbon monoxide still be experiencing some symptons such as memory lost and irrasionality 2-3 years after their exposure? - (Aug 11, 2012) dubose_gloria@yahoo.com
Reply:
Dubose,
Your question is posted on a carbon DIOXIDE page - please take a look at the Carbon MONOXIDE article (as that's what you're asking about) see
CARBON MONOXIDE - CO in the ARTICLE INDEX for more details.
In general, your question is important enough that you should take it to your physician or to a physician who specializes in environmental medicine or gas exposure effects.
You don't define serious: serious to me could be a short term exposure to very high level of a gas, or a long term exposure to a lower level, perhaps even chronic exposure to a low level of a gas. The potential effects of gas exposure thus vary by type of exposure as well, of course, as by the gas itself and by individual susceptability.
With those general remarks, and the "serious" exposure not described, we can only engage in guessing and arm-waving.
Usually people recover fine from short term exposure to CO; chronic exposure, or prolonged exposure to a gas that basically is depriving a person of sufficient oxygen, could potentially cause more lasting problems. But if you are saying that the problems did not manifest themselves until two or three years later, I'd expect your doctor to be also considering some other, more immediate conditions.
Question: will people in a car suffocate from CO2
Wonder if two people staying in a sedan car (sealed windows, no AC) will be suffocated of C02 in 30 minutes? - Atoi 9/10/2012
Reply:
Atoi I think you are confusing CO (carbon monoxide) with CO2 (carbon dioxide) - or perhaps you are postulating that the automobile is airtight and that people are going to exhaust the available oxygen or suffer from high CO2 levels. In our experience, vehicles are not air tight, and the hazards arise from carbon monoxide from an idling engine or an exhaust leak, though I would agree that people breathing in an enclosed space will indeed push the CO2 numbers up.
Take a look at TYPICAL CO2 LEVELS - separate article for some examples of indoor or enclosed space carbon dioxide levels.
Question:
What is the mechanism of action in cases of carbon dioxide poisoning, assuming that the organism is provided adequate oxygen, that is, it does not suffocate? - H Durden 10/8/2012
Reply:
The question you pose, along with both high CO2 effects and reduced oxygen efffects, is discussed in the article above.
Question: how long would it take for the CO2 levels to get dangerous in a closed room?
5/18/2014 Anonymous said:
I have tried many times but fail to get a reply on how long it would take for the CO2 levels to get to dangerous levels in a closed sealed room. I am of course well aware that few rooms are really tightly sealed but in fact with better doors and window seatings this is becoming an iffy point and with security concerns my wife at least insists on closing the bedroom door. Surely some kind of measures can be given to a moderately intelligent person to guage likely extreme points.Also of course likely effects of worsening states can be given .. headaches ? etc.
(Aug 26, 2014) Anonymous said: what is the standard management as work up and treatment approach
will you explain the approach consideration as regard the investigative tools for diagnosis and treatment protocol for CO2 poisoning cases
(Oct 8, 2014) joy said: pls what are the mechanism toxic action of carbon oxide as an indoorpollutant
Reply:
Anon, the problem may be the way you phrase the question.
There are clearly published exposure limits.
What's missing from the question as you put it is any data about concentrations. The concentration level of a ga in a space depends on a number of variables, such as (for an incomplete example)
Joy you'll want to take another look at the article above. Bascially, if high CO2 levels arise indoors the effect can be the replacement of oxygen. These articles, linked just above contain exposure limits & toxicity data
- the concentration of the gas that is entering the space
- the rate at which the gas is entering the space
- the rate at which fresh air is also entering or ventilating the space
- the volume of the space
Below at Continue Reading you'll find articles contain carbon dioxide exposure limits & toxicity data
Please take a look at them and let me know if questions remain.
...
Continue reading at CARBON DIOXIDE - CO2 - topic home, or select a topic from the closely-related articles below, or see the complete ARTICLE INDEX.
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In addition to any citations in the article above, a full list is available on request.
Bakó-Biró, Zs, Derek J. Clements-Croome, Neena Kochhar, Hazim B. Awbi, and Marilyn J. Williams. "Ventilation rates in schools and pupils’ performance." Building and Environment 48 (2012): 215-223.
Abstract:
This paper is a development of our earlier work [5], [6], [11]. The effects of classroom ventilation on pupils’ performance were investigated in 8 primary schools in England.
In each school the concentrations of carbon dioxide and other parameters were monitored for three weeks in two selected classrooms. In 16 classrooms interventions were made to improve the ventilation rate and maintain the temperature within an acceptable range using a purpose-built portable mechanical ventilation system.
As a result of the interventions the provision of outdoor air to the classrooms was improved from the prevailing levels of about 1 l/s per person to about 8 l/s per person.
The pupils and teachers in the classrooms studied were usually exposed to unacceptably poor air quality conditions, with CO2 concentrations of up to 5000 ppm, much higher than the average recommended levels of 1500 ppm and the preferred level of 1000 ppm.
The results of computerized performance tasks performed by more than 200 pupils showed significantly faster and more accurate responses for Choice Reaction (by 2.2%), Colour Word Vigilance (by 2.7%), Picture Memory (by 8%) and Word Recognition (by 15%) at the higher ventilation rates compared with the low ventilation conditions.
The present investigation provides strong evidence that low ventilation rates in classrooms significantly reduce pupils’ attention and vigilance, and negatively affect memory and concentration. The physical environment therefore affects teaching and learning.
Excerpt: Increased levels of CO2 from a mean of 690 ppm to a mean of 2909 ppm lead to a detriment
in power of attention of about 5%.". Satish et al
Dooley et al, GTSP, 2006: Carbon Dioxide Capture and Geologic Storage: A Core Element of a A Global
Energy Technology Strategy to Address Climate Change (PDF, 37 pp., 6.05 MB, About PDF).
April 2006, JJ Dooley et al. Global Energy Technology Strategy Program (GSTP)
[3] Fisher, Stephen, Australian and New Zealand Sales Director, K.D.Fisher & Company, Pty., Ltd. 18 Benjamin Street, St. Mary's, Adelaide, South Australia, 5042, Australia. Ph: (08) 8277-3288 (Int): +61-8-8277-3288 Fax: (08) 8276-4024 (Int): +61-8-8276-4024 E-mail: stevef@kdfisher.com.au [by email, Feb 2012] website: http://www.kdfisher.com.au/ Quoting from the company's website
KD Fisher & Co. Pty. Ltd., Safety and Welfare: OHS & W training facilities located on premises; Gas detection monitoring & consultation; Safety & Security products; Electric components, Power & switchgear products, Electrical/Electronic service & engineering
Mr. Fisher adds "Our company is family owned, and employs 30 personnel, and has been specifying, and designing gas detection systems, using "bought in" detectors from overseas manufacturers, and developing sampling systems to allow the most proficient system for many applications, including jet fuel leakage detection systems for military aircraft hangars, and tanker parking shelters, for the Australian Dept. of Defence. "
[3-a] Fisher, Stephen, "DANGERS OF CARBON DIOXIDE, HEALTH EFFECTS OF CARBON DIOXIDE GAS" [PDF], K.D. Fisher & Co. Pty, Ltd., 18 Benjamn St., St. Marys, Adelaide, South Australia 5042, website: www.kdfisher.com.au, Tel: 08-8277-3288. Offices in Sydney & Melbourne.
This document consists of selected reproductions from the CCOHS (Canada's National Occupational Health & Safety Resource) with minor Australian applications & modifications, and cites the InspectAPedia carbon dioxide gas hazards article found on this page.
[9] Bruggeman et al. 2007 Acid-base balance in chicken embryois...incubated under high CO2 concentrations... Respiratory Physiology and Neurobiology 159:147-154
[11] Bar-Ilan, Amir and Jacob Marder, Adaptations to Hypercapnic conditions in the Nutria..., Comp. Biochem. Physiol. Vol 75A, No 4, pp 603-608, 1983
[12] CCOHS "Health Effects of Carbon Dioxide Gas", CCOHS, Canadian Centre for Occupational Health and Safety, web search 02/15/2012, original source: http://www.ccohs.ca/oshanswers/chemicals/chem_profiles/carbon_dioxide/health_cd.html
[10] De Smit et al, 2006 Emryonic developmental plasticity of the chick: Increased CO2 ... Comparative Biochemistry and Physiology, Part A 145: 166-175
[8] Holloway and Heath, 1984 Ventilatory Changes in the Golden Hamster..., Laboratory Rat...., Comp. Biochem. Physiol., Vol. 77A, No 2, pp. 267-273
James, John T. "Surprising effects of CO2 exposure on decision making." In 43rd international conference on environmental systems, p. 3463. 2013. https://doi.org/10.2514/6.2013-3463 or https://arc.aiaa.org/doi/pdf/10.2514/6.2013-3463
Abstract: Carbon dioxide (CO2 ) is released from humans while they live and work in spacecraft or spacesuites. Removal of this anthropogenic pollutant requires major resources, which increase dramatically as the permissible levels of CO2 set to protect human health and performance are reduced.
The current Spacecraft Maximum Allowable Concentration (SMAC) of CO2 aboard the ISS is 5.3 mmHg; however, according to Chits (mission action requests), NASA and its international partners havce agreed to control CO2 levels to less than 4 mmHg.
In the meantime, retrospective investigations attempting to associate crew symptoms with elevated CO2 levels over the life of the International Space Station (ISS) are underway to determine if this level is sufficient to protect against health and performance decrements.
Anecdotal reports suggest that crewmembers are not able to perform complex tasks as readily in spaceflight as they were able to during ground-based training. Recently the effects of CO2 on decision making have been investigated. Using data from this one study, we show that there are obvious adverse effects of CO2 exposures on decision making above 1.5 mmHg.
The impications and limitations of this study are paramount in determining future CO2 SMACs for human spaceflight, both aboard the ISS and in exploration-class missions.
[6] Klemens C. Baczewski PE, email correspondence, 4/29/2009
discussed correct CO2 calculations.
Liu, Weiwei, Weidi Zhong, and Pawel Wargocki. "Performance, acute health symptoms and physiological responses during exposure to high air temperature and carbon dioxide concentration." Building and Environment 114 (2017): 96-105.
Abstract
Human subjects were exposed for 3 h in a climate chamber to the air temperature of 35 °C that is an action level, at which the working time needs to be diminished in China.
The purpose was to put this action level to test by measuring physiological responses, subjective ratings and cognitive performance, and compare them with responses at temperature of 26 °C (reference exposure). Moreover, CO2 was increased to 3000 ppm (CO2 exposure) at 35 °C to further examine, whether this change will have any effect on the measured responses.
Compared with the reference exposure, exposure to 35 °C caused subjects to report feeling uncomfortably warm, to rate the air quality as worse, to report increased sleepiness and higher intensity of several acute health symptoms.
Eardrum temperature, skin temperature, heart rate and body weight loss all increased significantly at this exposure, arterial oxygen saturation decreased significantly, while the percentage of adjacent inter-beat cardiac intervals differing by > 50 m (pNN50) decreased significantly, indicating elevated stress.
The performance of addition and subtraction tasks decreased significantly during this exposure, as well.
Increasing CO2 to 3000 ppm at 35 °C caused no significant changes in responses. Present results reaffirm the selection of 35 °C as an action level, and show that concurrently occurring high CO2 levels should not exacerbate the hazards.
Metz, Bert, Davidson, Ogunlade,
de Coninck, Heleen, Loos, Manuela, and Meyer, Leo (Eds.) IPCC, 2005: Special Report on Carbon Dioxide Capture and Storage, Special Report of the
Intergovernmental Panel on Climate Change []. Cambridge University Press, The
Edinburgh Building Shaftesbury Road, Cambridge CB2 2RU England
[5] OSHA, TABLE Z-1 LIMITS FOR AIR CONTAMINANTS, 1910.1000 TABLE Z-1 [PDF] OSHA standard for air contaminant limits (http://www.osha.gov/pls/oshaweb/owadisp.show_document?p_table=STANDARDS&p_id=9992) - includes for CO2, Carbon dioxide.........| CAS No. 124-38-9 | 5000 ppm | 9000 mg/m3 limits for carbon dioxide as an air contaminant.
[1] Per Levéen, email comments 23 May 2009
. Mr. Levéen is with Telia, the leading mobile telephone operator in Sverige (Sweden). By telephone Telia (not Mr. Levéen) can be reached at
90 200 or From abroad at +46-771-99 02 00
Satish, Usha, Mark J. Mendell, Krishnamurthy Shekhar, Toshifumi Hotchi, Douglas Sullivan, Siegfried Streufert, and William J. Fisk. "Is CO2 an indoor pollutant? Direct effects of low-to-moderate CO2 concentrations on human decision-making performance." Environmental health perspectives 120, no. 12 (2012): 1671-1677. Retrieved 2019/05/13, original source: https://ehp.niehs.nih.gov/doi/full/10.1289/ehp.1104789
Sliwka, U., J. A. Krasney, S. G. Simon, and P. Schmidt. "Effects of sustained low-level elevations of carbon dioxide on cerebral blood flow and autoregulation of the intracerebral arteries in humans." (1996).
[7] Taylor, Lewis G. and G. Oscar Kreutziger, The Gaseous Environment of the Chick Embryo in Relation to Its Development and Hatchability, 1968 (printout does not include the Journal)
Zhang, Xiaojing, Pawel Wargocki, and Zhiwei Lian. "Physiological responses during exposure to carbon dioxide and bioeffluents at levels typically occurring indoors." Indoor Air 27, no. 1 (2017): 65-77.
Zhang, Xiaojing, Pawel Wargocki, Zhiwei Lian, and Camilla Thyregod. "Effects of exposure to carbon dioxide and bioeffluents on perceived air quality, self‐assessed acute health symptoms, and cognitive performance." Indoor air 27, no. 1 (2017): 47-64.
Abstract: The purpose of this study was to examine the effects on humans of exposure to carbon dioxide (CO2) and bioeffluents. In three of the five exposures, the outdoor air supply rate was high enough to remove bioeffluents, resulting in a CO2 level of 500 ppm.
Chemically pure CO2 was added to this reference condition to create exposure conditions with CO2 at 1000 or 3000 ppm. In two further conditions, the outdoor air supply rate was restricted so that the bioeffluent CO2 reached 1000 or 3000 ppm. The same 25 subjects were exposed for 255 min to each condition. Subjective ratings, physiological responses, and cognitive performance were measured.
No statistically significant effects on perceived air quality, acute health symptoms, or cognitive performance were seen during exposures when CO2 was added.
Exposures to bioeffluents with CO2 at 3000 ppm reduced perceived air quality; increased the intensity of reported headache, fatigue, sleepiness, and difficulty in thinking clearly; and reduced speed of addition, the response time in a redirection task, and the number of correct links made in the cue‐utilization test.
This suggests that moderate concentrations of bioeffluents, but not pure CO2, will result in deleterious effects on occupants during typical indoor exposures.
In addition to citations & references found in this article, see the research citations given at the end of the related articles found at our suggested
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