50th 75th 90th 95th 97.5th 99th other Total
Cumulative intake (percentile) for an adverse outcome linked to acute exposures (24 hour) – assuming you have an estimated intake for the specific substance of interest 12.20% 15 4.88% 6 14.63% 18 30.89% 38 7.32% 9 17.07% 21 13.01% 16 123
Cumulative intake (percentile) for an adverse outcome linked to chronic exposures – assuming you have an estimated intake for the specific substance of interest 21.77% 27 9.68% 12 14.52% 18 33.06% 41 3.23% 4 7.26% 9 10.48% 13 124

Answer Explanations 60

user-189445
Scenario50th75th90th95th97.5th99thother
Cumulative intake (percentile) for an adverse outcome linked to acute exposures (24 hour) – assuming you have an estimated intake for the specific substance of interest0000001
Cumulative intake (percentile) for an adverse outcome linked to chronic exposures – assuming you have an estimated intake for the specific substance of interest0001000
US-EPA suggest to use, for the acute exposures, the 99.9th percentile, while the 95th percentile is a good choice for the chronic exposures
user-484519
Scenario50th75th90th95th97.5th99thother
Cumulative intake (percentile) for an adverse outcome linked to acute exposures (24 hour) – assuming you have an estimated intake for the specific substance of interest0001000
Cumulative intake (percentile) for an adverse outcome linked to chronic exposures – assuming you have an estimated intake for the specific substance of interest0000001
Statistics selected ultimately depends on the sample size, number of detected analytes to non-detected and the use profile of what is being assessed. For chronic exposures, an upper bound on a central estimate (e.g. a 95UCLM) or an average may be appropriate if there is enough quality data. Otherwise, a higher percentile but not higher than 90th. Suggest using stat software. For acute, a more maximal statistic is appropriate (such as a 95th, or even the max, but it depends on sample size). Consider chemical half lives in relation to time between exposures as well - see Health Canada short-term exposure guidance (in Appendix of the latest Health Canada Preliminary Quantitative Risk Assessment Guidance, 2021).
user-280873
Scenario50th75th90th95th97.5th99thother
Cumulative intake (percentile) for an adverse outcome linked to acute exposures (24 hour) – assuming you have an estimated intake for the specific substance of interest0000010
Cumulative intake (percentile) for an adverse outcome linked to chronic exposures – assuming you have an estimated intake for the specific substance of interest0000010
You like t protect as large a proportion of the populations as possible
user-148776
Scenario50th75th90th95th97.5th99thother
Cumulative intake (percentile) for an adverse outcome linked to acute exposures (24 hour) – assuming you have an estimated intake for the specific substance of interest0001000
Cumulative intake (percentile) for an adverse outcome linked to chronic exposures – assuming you have an estimated intake for the specific substance of interest0001000
Conservative, health-protective; use has precedence; values of uncertainty factors do need to be appropriately adjusted.
user-371682
Scenario50th75th90th95th97.5th99thother
Cumulative intake (percentile) for an adverse outcome linked to acute exposures (24 hour) – assuming you have an estimated intake for the specific substance of interest0000001
Cumulative intake (percentile) for an adverse outcome linked to chronic exposures – assuming you have an estimated intake for the specific substance of interest0000001
In the case of heavy metals, which I am more familiar, it depends on the element in question. Some metals (Hg, Pb, Cd) intake should be zero or near zero; and others will vary.
user-734085
Scenario50th75th90th95th97.5th99thother
Cumulative intake (percentile) for an adverse outcome linked to acute exposures (24 hour) – assuming you have an estimated intake for the specific substance of interest0001000
Cumulative intake (percentile) for an adverse outcome linked to chronic exposures – assuming you have an estimated intake for the specific substance of interest0010000
A meaningful acute rxn more likely to have validity over a cumulative chronic exposure. The levels and activities of cytochrome P450 enzymes are influenced by a variety of factors, including the diet. While short term studies likely to have controlled baseline and some predictive outcome reliability, increased utility in animal experiments might occur if different P450 treated diets were used in generating possible acute toxicity profiles. A more comprehensive assessment system to elucidate the effects of 'probiotic' health foods from for P450 mediated metabolites might be required for possible adverse outcomes. Active culture foods, such as yogurt, sour dill pickles, kefir, · kimchi, · kombucha, miso, natto, sauerkraut and others are currently on the uptake in human dietary practices, need to be placed into a risk assessment strategy system.
user-424090
Scenario50th75th90th95th97.5th99thother
Cumulative intake (percentile) for an adverse outcome linked to acute exposures (24 hour) – assuming you have an estimated intake for the specific substance of interest0001000
Cumulative intake (percentile) for an adverse outcome linked to chronic exposures – assuming you have an estimated intake for the specific substance of interest0001000
The use of higher percentiles (i.e., >95P) may be necessary/warranted when there is low confidence in the estimates. As was pointed out by Paustenbach, the selection of the 95P for each individual input variable for Estimated Daily Intake would cause the EDI selection to actually exceed >99th percentile.
user-684816
Scenario50th75th90th95th97.5th99thother
Cumulative intake (percentile) for an adverse outcome linked to acute exposures (24 hour) – assuming you have an estimated intake for the specific substance of interest0010000
Cumulative intake (percentile) for an adverse outcome linked to chronic exposures – assuming you have an estimated intake for the specific substance of interest0010000
According to the FDA guidance
Scenario50th75th90th95th97.5th99thother
Cumulative intake (percentile) for an adverse outcome linked to acute exposures (24 hour) – assuming you have an estimated intake for the specific substance of interest0000010
Cumulative intake (percentile) for an adverse outcome linked to chronic exposures – assuming you have an estimated intake for the specific substance of interest0000010
Assuming the largest consumer’s exposure would encompass the light to moderate exposure as well.
user-726131
Scenario50th75th90th95th97.5th99thother
Cumulative intake (percentile) for an adverse outcome linked to acute exposures (24 hour) – assuming you have an estimated intake for the specific substance of interest0001000
Cumulative intake (percentile) for an adverse outcome linked to chronic exposures – assuming you have an estimated intake for the specific substance of interest0001000
(1) The 95th percentile offers a credible conservative estimate of exposure, (2) Estimated consumption percentiles >95th percentile tend to be affected by small sample size, and as such, don't tend to be very reliable.
Scenario50th75th90th95th97.5th99thother
Cumulative intake (percentile) for an adverse outcome linked to acute exposures (24 hour) – assuming you have an estimated intake for the specific substance of interest0001000
Cumulative intake (percentile) for an adverse outcome linked to chronic exposures – assuming you have an estimated intake for the specific substance of interest0001000
As once mentioned to me by a high level FDA Foods branch head: our job is to protect people and fools, not damn fools.
user-370908
Scenario50th75th90th95th97.5th99thother
Cumulative intake (percentile) for an adverse outcome linked to acute exposures (24 hour) – assuming you have an estimated intake for the specific substance of interest0010000
Cumulative intake (percentile) for an adverse outcome linked to chronic exposures – assuming you have an estimated intake for the specific substance of interest1000000
On a general condition, it causes an adverse effect. Therefore, when being exposed to such pollutant in 75 % within 24 hrs, it will cause acute effect while in 50% for a long period, it will cause chronic effect since the higher the accumulation, the faster its reaction and the higher it's the effect. It's always SN1 reaction which is being determined by one reactant that is the pollutant.
user-678105
Scenario50th75th90th95th97.5th99thother
Cumulative intake (percentile) for an adverse outcome linked to acute exposures (24 hour) – assuming you have an estimated intake for the specific substance of interest0000001
Cumulative intake (percentile) for an adverse outcome linked to chronic exposures – assuming you have an estimated intake for the specific substance of interest0000001
Can't rely on estimated intake. Need to consider outliers as well.
user-777357
Scenario50th75th90th95th97.5th99thother
Cumulative intake (percentile) for an adverse outcome linked to acute exposures (24 hour) – assuming you have an estimated intake for the specific substance of interest1000000
Cumulative intake (percentile) for an adverse outcome linked to chronic exposures – assuming you have an estimated intake for the specific substance of interest1000000
Any intake of a substance that leads to an adverse outcome is of immediate concern.
user-747537
Scenario50th75th90th95th97.5th99thother
Cumulative intake (percentile) for an adverse outcome linked to acute exposures (24 hour) – assuming you have an estimated intake for the specific substance of interest0001000
Cumulative intake (percentile) for an adverse outcome linked to chronic exposures – assuming you have an estimated intake for the specific substance of interest0001000
Just a common sense
user-37600
Scenario50th75th90th95th97.5th99thother
Cumulative intake (percentile) for an adverse outcome linked to acute exposures (24 hour) – assuming you have an estimated intake for the specific substance of interest0000010
Cumulative intake (percentile) for an adverse outcome linked to chronic exposures – assuming you have an estimated intake for the specific substance of interest0000100
I hope no one treats these answers (anyone's own or the group mean or upper bound) as a single "right answer." If allowed, I would have chosen different percentiles depending on important things such as (1) the number of people exposed (1% left behind of 100 million is a lot worse than 1% left behind of 100 people!); or (2) the ratio of the 99th/95th etc (if the tail isn't long, the percentile doesn't matter as much). anyway, because intakes vary much more person-to-person over a day than over a lifetime, one can use a less strict %ile for the latter-- but still, risk assessment should strive to protect-- or at least honestly DESCRIBE the risks to-- as many people as reasonable.
Scenario50th75th90th95th97.5th99thother
Cumulative intake (percentile) for an adverse outcome linked to acute exposures (24 hour) – assuming you have an estimated intake for the specific substance of interest1000000
Cumulative intake (percentile) for an adverse outcome linked to chronic exposures – assuming you have an estimated intake for the specific substance of interest1000000
You always have a safety margin of 1000.
user-960199
Scenario50th75th90th95th97.5th99thother
Cumulative intake (percentile) for an adverse outcome linked to acute exposures (24 hour) – assuming you have an estimated intake for the specific substance of interest0001000
Cumulative intake (percentile) for an adverse outcome linked to chronic exposures – assuming you have an estimated intake for the specific substance of interest0100000
I am assuming that the link to the adverse outcome is one related to the estimated safe dose. If not, for example, if the link is to the benchmark dose of NOAEL, then the percentiles would be higher in both categories.
user-13124
Scenario50th75th90th95th97.5th99thother
Cumulative intake (percentile) for an adverse outcome linked to acute exposures (24 hour) – assuming you have an estimated intake for the specific substance of interest0000010
Cumulative intake (percentile) for an adverse outcome linked to chronic exposures – assuming you have an estimated intake for the specific substance of interest0000010
I take a conservative approach to risk assessment. Using the 99th percentile still has potential consequences for a portion of the population but it is probable the best we can do.
user-641377
Scenario50th75th90th95th97.5th99thother
Cumulative intake (percentile) for an adverse outcome linked to acute exposures (24 hour) – assuming you have an estimated intake for the specific substance of interest0000100
Cumulative intake (percentile) for an adverse outcome linked to chronic exposures – assuming you have an estimated intake for the specific substance of interest0010000
Choice may be more of a policy decision, but this is consistent with how most risk assessment agencies conduct their assessments (US GRAS typically used 90th for chronic effects, these values are referenced in EHC 240)
user-802001
Scenario50th75th90th95th97.5th99thother
Cumulative intake (percentile) for an adverse outcome linked to acute exposures (24 hour) – assuming you have an estimated intake for the specific substance of interest0000010
Cumulative intake (percentile) for an adverse outcome linked to chronic exposures – assuming you have an estimated intake for the specific substance of interest0001000
Acute exposure can be relatively well evaluated, with small error bars. Societal policies on precaution have less impact. Chronic exposure has far greater errors associated with the exposure modeling and its use in an overall assessment of risk/safety.
user-223762
Scenario50th75th90th95th97.5th99thother
Cumulative intake (percentile) for an adverse outcome linked to acute exposures (24 hour) – assuming you have an estimated intake for the specific substance of interest0000100
Cumulative intake (percentile) for an adverse outcome linked to chronic exposures – assuming you have an estimated intake for the specific substance of interest0100000
For both intake values, I try to be conservative. However, for acute exposure, we have less buffer zone for mitigating uncertainty, therefore, I choose 97.5th to be more conservative. On the other hand, I choose 75th percentile for chronic exposures.
user-863552
Scenario50th75th90th95th97.5th99thother
Cumulative intake (percentile) for an adverse outcome linked to acute exposures (24 hour) – assuming you have an estimated intake for the specific substance of interest0100000
Cumulative intake (percentile) for an adverse outcome linked to chronic exposures – assuming you have an estimated intake for the specific substance of interest1000000
Chronic assessment estimates average (mean) dietary exposure of an individual over a long term. While acute assessment estimates range of exposure of individual in a day as well as exposure to which high-end individual could be subjected. This is mainly adopted in Monte Carlo 99.9th percentile assessment. Nevertheless, the default intake value that should be used to guide in risk assessment is a value that reflect the amount of the toxicant to which an individual may be safely be exposed in a day (I.e acute or chronic Population Adjusted Dose).
user-568577
Scenario50th75th90th95th97.5th99thother
Cumulative intake (percentile) for an adverse outcome linked to acute exposures (24 hour) – assuming you have an estimated intake for the specific substance of interest0000001
Cumulative intake (percentile) for an adverse outcome linked to chronic exposures – assuming you have an estimated intake for the specific substance of interest0001000
For acute exposure, the cumulative intake for an adverse outcome is 99.9th percentile.
user-420611
Scenario50th75th90th95th97.5th99thother
Cumulative intake (percentile) for an adverse outcome linked to acute exposures (24 hour) – assuming you have an estimated intake for the specific substance of interest0001000
Cumulative intake (percentile) for an adverse outcome linked to chronic exposures – assuming you have an estimated intake for the specific substance of interest0001000
Any value of 95 or above would be fine.
user-824954
Scenario50th75th90th95th97.5th99thother
Cumulative intake (percentile) for an adverse outcome linked to acute exposures (24 hour) – assuming you have an estimated intake for the specific substance of interest0000010
Cumulative intake (percentile) for an adverse outcome linked to chronic exposures – assuming you have an estimated intake for the specific substance of interest0000010
Dietary Risk Evaluation System DRES standard is 95th percentile while Monte Carlo analysis standard is 99.9th percentile for acute exposure risk assessment. For chronic exposure, estimates are made for the average amount of toxin/intake substance a person might consume over extended periods, potentially ranging from several months to a lifetime to cause chronic exposure effects. For acute exposure, the estimates are made for amount that might be ingested on a single day without adverse effects. Total margin of exposure (MOET), the ratio of the toxicological reference dose to the estimated exposure is often used for chronic exposure, MOET of 100 at 99.9th percentile of exposure at whole population level is considered as the threshold for regulatory consideration. The MOET could be calculated from 50th percentile up to 99.9th percentile and depending on the toxicity of the substance actions could be implemented.
user-971739
Scenario50th75th90th95th97.5th99thother
Cumulative intake (percentile) for an adverse outcome linked to acute exposures (24 hour) – assuming you have an estimated intake for the specific substance of interest0000001
Cumulative intake (percentile) for an adverse outcome linked to chronic exposures – assuming you have an estimated intake for the specific substance of interest0000001
Answer depends on confidence bounds of the estimated intake and associated toxic/adverse outcome. It is also relevant if any additional uncertainty or precautionary multiple is factored into the risk assessment.
user-44105
Scenario50th75th90th95th97.5th99thother
Cumulative intake (percentile) for an adverse outcome linked to acute exposures (24 hour) – assuming you have an estimated intake for the specific substance of interest1000000
Cumulative intake (percentile) for an adverse outcome linked to chronic exposures – assuming you have an estimated intake for the specific substance of interest0100000
First would be for acute and second for exposure over long term which would be more exact.
user-153764
Scenario50th75th90th95th97.5th99thother
Cumulative intake (percentile) for an adverse outcome linked to acute exposures (24 hour) – assuming you have an estimated intake for the specific substance of interest0010000
Cumulative intake (percentile) for an adverse outcome linked to chronic exposures – assuming you have an estimated intake for the specific substance of interest0010000
In general the 90% is selected as a default value. Rather than an 'estimated' numerical value, using a range of measured dietary intake values to determine exposure provides the risk manager with a view of the full range of plausible values.
user-265194
Scenario50th75th90th95th97.5th99thother
Cumulative intake (percentile) for an adverse outcome linked to acute exposures (24 hour) – assuming you have an estimated intake for the specific substance of interest0000001
Cumulative intake (percentile) for an adverse outcome linked to chronic exposures – assuming you have an estimated intake for the specific substance of interest0000001
The goal of risk managers is to protect everyone. Thus you want to model 100%. A Monte Carlo analysis approach has the ability to assess the typical individuals and some of the individuals out at the tails. But the percentiles that can be modeled accurately are limited by 1) the quality of the data on the variation in critical inputs, and 2) the accuracy of the model for individuals at the extremes. Monte Carlo analysis of interindividual variation should generally be done on the largest percentiles possible. The expectation is that interindividual variation in chronic exposures will be smaller than inter individual variation in chronic exposures but the goal is the same - as far out as you can.
user-360527
Scenario50th75th90th95th97.5th99thother
Cumulative intake (percentile) for an adverse outcome linked to acute exposures (24 hour) – assuming you have an estimated intake for the specific substance of interest0000100
Cumulative intake (percentile) for an adverse outcome linked to chronic exposures – assuming you have an estimated intake for the specific substance of interest0001000
In case of chronic (lifetime) exposures for budget method 95th should be used. The choice of upper percentile of dietary expose is dependent on the purpose of dietary exposure assessment and data available. For statistically valid estimates 95-97.5th. For population subgroups when some data sets may not be met 90th percentile should be used.
user-864496
Scenario50th75th90th95th97.5th99thother
Cumulative intake (percentile) for an adverse outcome linked to acute exposures (24 hour) – assuming you have an estimated intake for the specific substance of interest0010000
Cumulative intake (percentile) for an adverse outcome linked to chronic exposures – assuming you have an estimated intake for the specific substance of interest1000000
For acute exposures, I would be more conservative to use a high-end exposure level. As the US EPA often uses the 90th percentile exposure as a conservative estimate, I prefer the 90th percentile. For chronic exposure, I would use the median.
user-351505
Scenario50th75th90th95th97.5th99thother
Cumulative intake (percentile) for an adverse outcome linked to acute exposures (24 hour) – assuming you have an estimated intake for the specific substance of interest0001000
Cumulative intake (percentile) for an adverse outcome linked to chronic exposures – assuming you have an estimated intake for the specific substance of interest0001000
Typical FDA uses 90% as threshold for chronic assessment while EFSA uses much higher threshold of 97.5% for their risk assessment. I would land at 95% for our internal risk assessment for internal projects.
user-294539
Scenario50th75th90th95th97.5th99thother
Cumulative intake (percentile) for an adverse outcome linked to acute exposures (24 hour) – assuming you have an estimated intake for the specific substance of interest0001000
Cumulative intake (percentile) for an adverse outcome linked to chronic exposures – assuming you have an estimated intake for the specific substance of interest1000000
Acute: I think it should vary between 90-99% depending upon the situation, including size and nature of population at risk, quality and quantity of data, other assumptions used in the assessment, severity of toxic effect, confidence of toxicology endpoint, etc. 95 is probably a reasonable default starting point
user-152430
Scenario50th75th90th95th97.5th99thother
Cumulative intake (percentile) for an adverse outcome linked to acute exposures (24 hour) – assuming you have an estimated intake for the specific substance of interest0000010
Cumulative intake (percentile) for an adverse outcome linked to chronic exposures – assuming you have an estimated intake for the specific substance of interest1000000
Acute effects need to be assessed based on the highest possible exposure.
user-821082
Scenario50th75th90th95th97.5th99thother
Cumulative intake (percentile) for an adverse outcome linked to acute exposures (24 hour) – assuming you have an estimated intake for the specific substance of interest0000100
Cumulative intake (percentile) for an adverse outcome linked to chronic exposures – assuming you have an estimated intake for the specific substance of interest0001000
When the survey has two days of records for each respondent, these data are pooled (as individual eating days, not averaged across two days) before deriving the 97.5th (for acute) and 90th (for chronic) percentile food consumption.
user-320876
Scenario50th75th90th95th97.5th99thother
Cumulative intake (percentile) for an adverse outcome linked to acute exposures (24 hour) – assuming you have an estimated intake for the specific substance of interest0000001
Cumulative intake (percentile) for an adverse outcome linked to chronic exposures – assuming you have an estimated intake for the specific substance of interest0000001
The question is somewhat confusing--Other factors should be included before duration or frequency of an individual exposure to toxic substances are dealt with.
user-200863
Scenario50th75th90th95th97.5th99thother
Cumulative intake (percentile) for an adverse outcome linked to acute exposures (24 hour) – assuming you have an estimated intake for the specific substance of interest0000001
Cumulative intake (percentile) for an adverse outcome linked to chronic exposures – assuming you have an estimated intake for the specific substance of interest0000001
We usually use the maximum exposure possible unless specific information of exposure is available. Using the maximum possible exposure values provides worst-case scenarios and be conservative enough to make sure that none of the outliers (sensitive individuals in a population) are left. In an industrial setting, we use the maximum possible exposure when details are not available; however, whenever we have more detailed information like use patterns of chemicals (e.g., pesticides), residue levels, gender, age, etc. then we refine exposure (acute or chronic daily) for the risk assessment as needed.
user-891891
Scenario50th75th90th95th97.5th99thother
Cumulative intake (percentile) for an adverse outcome linked to acute exposures (24 hour) – assuming you have an estimated intake for the specific substance of interest0000010
Cumulative intake (percentile) for an adverse outcome linked to chronic exposures – assuming you have an estimated intake for the specific substance of interest0001000
Risk assessment is meant to provide protection for all population including the high-end users, so worst-case estimates should be taken. A person may take in an extremely high amount of substance in a short period so I recommend using the 99th percentile for acute exposures, but it's probably unlikely that a person would consume an extremely high amount of substance every day over a long period so I would use the 95th percentile for chornic exposures.
user-324000
Scenario50th75th90th95th97.5th99thother
Cumulative intake (percentile) for an adverse outcome linked to acute exposures (24 hour) – assuming you have an estimated intake for the specific substance of interest0000010
Cumulative intake (percentile) for an adverse outcome linked to chronic exposures – assuming you have an estimated intake for the specific substance of interest0000001
It is important to consider both the percentile of the distribution as well as the method by which the distribution is calculated. The tails of the distribution are very sensitive to the shape of the curve and the extent and quality of the data. It is my understanding that OPP uses the 99.9th percentile of the distribution to estimate acute dietary food exposures but does not use Monte Carlo techniques for chronic exposures (https://www.epa.gov/sites/default/files/2015-07/documents/trac2b054_0.pdf) due to data limitations.
user-250140
Scenario50th75th90th95th97.5th99thother
Cumulative intake (percentile) for an adverse outcome linked to acute exposures (24 hour) – assuming you have an estimated intake for the specific substance of interest0010000
Cumulative intake (percentile) for an adverse outcome linked to chronic exposures – assuming you have an estimated intake for the specific substance of interest1000000
For acute adverse outcome, occasional high intake should be taken in account, but for chronic adverse outcome, cumulative average intake value will be sufficient.
user-852334
Scenario50th75th90th95th97.5th99thother
Cumulative intake (percentile) for an adverse outcome linked to acute exposures (24 hour) – assuming you have an estimated intake for the specific substance of interest0000010
Cumulative intake (percentile) for an adverse outcome linked to chronic exposures – assuming you have an estimated intake for the specific substance of interest1000000
Acute toxicity is usually examined in oral/inhalation dosing animal studies of short (4h) exposure duration over a period of 1 to a few days and is expressed in terms of LD50/LC50. Hence, the risk assessment is interested in a high-end single day exposures (i.e. sum(food item intake * conc. of chemical in food item)), which can be best described with higher percentiles (e.g. P99.9 in US EPA 2001 guidance https://www.epa.gov/sites/default/files/2015-07/documents/trac2b054_0.pdf). However, the choice of the percentile will very much depend on: 1. the quality of the survey underpinning the exposure estimates, incl. sample size, data collection and exposure estimation method, treatment of outliers, etc. It is therefore advisable to always include a quality check of all high-end exposures to evaluate the impact of high-end consumption levels on these exposure levels. 2. the margin of safety that is already incorporated into the toxicological value of the risk evaluation. 3. percentage of the population potentially at risk that is considered to be acceptable. Further references: Boon et al. (2004) https://edepot.wur.nl/28647 Section 3.5 Bokkers et al. (2009) https://www.rivm.nl/bibliotheek/rapporten/320121001.pdf
user-571430
Scenario50th75th90th95th97.5th99thother
Cumulative intake (percentile) for an adverse outcome linked to acute exposures (24 hour) – assuming you have an estimated intake for the specific substance of interest0010000
Cumulative intake (percentile) for an adverse outcome linked to chronic exposures – assuming you have an estimated intake for the specific substance of interest1000000
In such studies, researchers face two challenges: the effect size, and the number of the "exposed". In the case of acute effects. it is reasonable to isolate those with an intake at least above the 90th percentile. In the case of long-term outcomes, having a low intake reference would allow to look at dose-response gradients in risk.
user-604552
Scenario50th75th90th95th97.5th99thother
Cumulative intake (percentile) for an adverse outcome linked to acute exposures (24 hour) – assuming you have an estimated intake for the specific substance of interest0100000
Cumulative intake (percentile) for an adverse outcome linked to chronic exposures – assuming you have an estimated intake for the specific substance of interest0100000
There is no a right or wrong answer. It depends from many parameters such as the way and level of estimation of hazard, the uncertainty of the exposure estimation, politically set level of desired safety etc. Though high percentages on both hazard and exposure can leed to non realistic scenarios I consider that 50% is too low and excludes high consumers. 75% is again low but it is a more balanced value.
user-574134
Scenario50th75th90th95th97.5th99thother
Cumulative intake (percentile) for an adverse outcome linked to acute exposures (24 hour) – assuming you have an estimated intake for the specific substance of interest0000001
Cumulative intake (percentile) for an adverse outcome linked to chronic exposures – assuming you have an estimated intake for the specific substance of interest0000001
Adopting a conservative approach by considering maximum published intake values across a population ensures all the population is protected and not just a portion eg 5% at the 95th percentile of intakes. If this then generates a problem refinement of the intake values can be undertaken through robust and rigorous experimental work. This thus adopts the precautionary principle in public health with evidenced-based refinement as may be required. In my experience its that small highly sensitive sub-group in the population that needs this type of protection.
user-581005
Scenario50th75th90th95th97.5th99thother
Cumulative intake (percentile) for an adverse outcome linked to acute exposures (24 hour) – assuming you have an estimated intake for the specific substance of interest0000001
Cumulative intake (percentile) for an adverse outcome linked to chronic exposures – assuming you have an estimated intake for the specific substance of interest0001000
In the current state of controls in Europe it is likely that any reaction in 24 hours ( excluding contamination ) will be allergic in pathogenesis. No centile value can deal with this. My "later effects" answer assumes that this is not based on extreem consumers
user-742167
Scenario50th75th90th95th97.5th99thother
Cumulative intake (percentile) for an adverse outcome linked to acute exposures (24 hour) – assuming you have an estimated intake for the specific substance of interest0000001
Cumulative intake (percentile) for an adverse outcome linked to chronic exposures – assuming you have an estimated intake for the specific substance of interest0000001
I propose to use the usual descriptive statistics for the assessment. With statistics software, it is easy to change from mean or median values to 75% or higher. The histogram and an assessment of quality of data will be further guidance to exclude outliers; measured values for good quality data, even if are far above 95% or in case of many values below liit of detection should be included in first approach; later with the matehamtical handling can be excluded. I suggest to consult the European database on concrete numbers for intake of food groups https://www.efsa.europa.eu/en/data-report/food-consumption-data#the-efsa-comprehensive-european-food-consumption-database There is also a lot of information on nutrients, energy, etc.from the EFSA website available (database and reports)
user-805266
Scenario50th75th90th95th97.5th99thother
Cumulative intake (percentile) for an adverse outcome linked to acute exposures (24 hour) – assuming you have an estimated intake for the specific substance of interest0000010
Cumulative intake (percentile) for an adverse outcome linked to chronic exposures – assuming you have an estimated intake for the specific substance of interest0010000
For GRAS conclusions, we would assume intake of a substance at the 90th percentile of all consumers, which would be more representative of lifetime exposure in the food supply. However for acute exposures, I would likely assume a worst case 99th percentile or higher.
Scenario50th75th90th95th97.5th99thother
Cumulative intake (percentile) for an adverse outcome linked to acute exposures (24 hour) – assuming you have an estimated intake for the specific substance of interest0001000
Cumulative intake (percentile) for an adverse outcome linked to chronic exposures – assuming you have an estimated intake for the specific substance of interest0010000
95% represents 4 times the average intake and 90% represents 2 times the average intake.
user-97194
Scenario50th75th90th95th97.5th99thother
Cumulative intake (percentile) for an adverse outcome linked to acute exposures (24 hour) – assuming you have an estimated intake for the specific substance of interest
Cumulative intake (percentile) for an adverse outcome linked to chronic exposures – assuming you have an estimated intake for the specific substance of interest0000010
Dietary exposures are best represented by chronic exposures. I would use 99th percentile value to be more protective. Nevertheless, I would not ignore acute exposure doses if the values derived from acute exposures are lower for health outcomes.
user-604069
Scenario50th75th90th95th97.5th99thother
Cumulative intake (percentile) for an adverse outcome linked to acute exposures (24 hour) – assuming you have an estimated intake for the specific substance of interest0000001
Cumulative intake (percentile) for an adverse outcome linked to chronic exposures – assuming you have an estimated intake for the specific substance of interest0001000
A cumulative intake for acute exposure needs further explanation.
user-526834
Scenario50th75th90th95th97.5th99thother
Cumulative intake (percentile) for an adverse outcome linked to acute exposures (24 hour) – assuming you have an estimated intake for the specific substance of interest0000010
Cumulative intake (percentile) for an adverse outcome linked to chronic exposures – assuming you have an estimated intake for the specific substance of interest0001000
The percentile should be matched to the severity of effect. Acute toxicity effects tend toward severe effects, thus a more extreme percentile is desirable. Chronic exposures tend to be set on much more mild effects, hence a 95th percentile is more acceptable.
user-97622
Scenario50th75th90th95th97.5th99thother
Cumulative intake (percentile) for an adverse outcome linked to acute exposures (24 hour) – assuming you have an estimated intake for the specific substance of interest0000001
Cumulative intake (percentile) for an adverse outcome linked to chronic exposures – assuming you have an estimated intake for the specific substance of interest0000001
Ideally, 95th - 99th percentile would be appropriate as a reasonably foreseeable worst (or "conservative" or "very conservative") case but need to consider/assess the quality and representativeness of the information going into the assessment's calculations/assumptions. Also, consider the goals of the risk assessment vs. the information/assumptions being used. Are they representative of the population of the country/state/region and the diet, e.g., possible/likely heterogeneity of the diet and in the consumers of the food(s)? Further, see the Chapter 4 (Exposure to Substances via Food Consumption) and other content in chapters of "The Practice of Consumer Exposure Assessment" book (numerous pages mention "default" if you check the index.
Scenario50th75th90th95th97.5th99thother
Cumulative intake (percentile) for an adverse outcome linked to acute exposures (24 hour) – assuming you have an estimated intake for the specific substance of interest0001000
Cumulative intake (percentile) for an adverse outcome linked to chronic exposures – assuming you have an estimated intake for the specific substance of interest0001000
Most dietary intake surveys are questionnaire based and rely on the memory of the respondents. Most are single day or 2 day surveys. Consequently aberrant responses can create quite a tail at wither end of the distribution and data at the very high or very low end is relatively unreliable particularly for chronic intake. Someone who loves cherries might eat a kilo of cherries on two consecutive days when they come into season but is very unlikely to do so over a prolonged period for example. Equally intakes for many foods at the extreme end are unhealthy regardless of the presence of additives or contaminants and risk assessments at such extremes are arguable inappropriate for additives or contaminants.
user-874787
Scenario50th75th90th95th97.5th99thother
Cumulative intake (percentile) for an adverse outcome linked to acute exposures (24 hour) – assuming you have an estimated intake for the specific substance of interest0010000
Cumulative intake (percentile) for an adverse outcome linked to chronic exposures – assuming you have an estimated intake for the specific substance of interest0010000
Using the 90th percentile as a threshold to guide the risk assessments for adverse outcomes for both acute and chronic exposure seems acceptable looking at the distribution of extreme values of the risk assessment
user-248520
Scenario50th75th90th95th97.5th99thother
Cumulative intake (percentile) for an adverse outcome linked to acute exposures (24 hour) – assuming you have an estimated intake for the specific substance of interest0000100
Cumulative intake (percentile) for an adverse outcome linked to chronic exposures – assuming you have an estimated intake for the specific substance of interest0001000
Depending on the region, for chronic exposure, FDA may use 90th percentile or above while EFSA uses 95th
catherine_sherwin
Scenario50th75th90th95th97.5th99thother
Cumulative intake (percentile) for an adverse outcome linked to acute exposures (24 hour) – assuming you have an estimated intake for the specific substance of interest0000010
Cumulative intake (percentile) for an adverse outcome linked to chronic exposures – assuming you have an estimated intake for the specific substance of interest0000100
Based on recommendations for dietary exposure assessment for chemicals in foods.
user-209936
Scenario50th75th90th95th97.5th99thother
Cumulative intake (percentile) for an adverse outcome linked to acute exposures (24 hour) – assuming you have an estimated intake for the specific substance of interest0000010
Cumulative intake (percentile) for an adverse outcome linked to chronic exposures – assuming you have an estimated intake for the specific substance of interest0000010
Using the 99th percentile will give a conservative answer, protetive of the most vulnerable person. This value will likely be exaggerated for most of the population, will will be erring on the side of safety. In the worst case, the value will be two fold higher which is an acceptable degree of safety. If the body weiight used is also on the high end of the spectrum, dose per kg will be corrected.
user-659046
Scenario50th75th90th95th97.5th99thother
Cumulative intake (percentile) for an adverse outcome linked to acute exposures (24 hour) – assuming you have an estimated intake for the specific substance of interest0000001
Cumulative intake (percentile) for an adverse outcome linked to chronic exposures – assuming you have an estimated intake for the specific substance of interest0000001
10th percentile, to be on the precautionary side
user-100225
Scenario50th75th90th95th97.5th99thother
Cumulative intake (percentile) for an adverse outcome linked to acute exposures (24 hour) – assuming you have an estimated intake for the specific substance of interest0000001
Cumulative intake (percentile) for an adverse outcome linked to chronic exposures – assuming you have an estimated intake for the specific substance of interest0000001
There should not be a one-size-fits-all approach. Example: ethanol. It is acutely and chronically toxic and a known human teratogen with a sensitivity window, plus zero order kinetics versus first order. Even for this one substance the risk assessment needs to be tailored to the specific area of concern and the known metabolic features of the substance. A single number approach is inappropriate. For a food contaminant with acute tox potential, e.g. organophosphate pesticide residue, which has a reversible effect and is rapidly metabolized, the cumulative intake for a chronic risk endpoint may be the same as for the acute effect. If a high-confidence intake assessment is available, use it. Any warranted intake adjustment, up or down, acute or chronic, should be scientifically justified based on the specific case. A degree of uncertainty underlies all risk assessments. Considering that uncertainty in each risk assessment is a necessary undertaking. We create a false impression of accuracy by using "default" values.
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user-42852
05/05/2022 03:52

FDA regulations vary from one country to the other. While making food risk assessments, generally the acute and chronic exposures of food component/s or food additive/s in question has to be tested by employing model organism. Due to restrictions imposed by animal ethics in the use of mammalian models, it can be tested on a limited number of animals. However, animal models like C. elegans or Drosophila can be employed in greater numbers to determine toxicity under various environmental conditions and 95% survival denotes safety. In addition, the populations that have been exposed to sub-lethal doses can be utilized for evaluating various parameters such as life span, reproductive safety, recessive mutations, biochemical changes etc.,

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