Compound intake estimator: Difference between revisions

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Compound intake estimator calculates intakes of compounds based on food or food supplement intake, compound concentration in food, and guidance values for the compound. In the text, we talk about plant-based food supplements (PFSs), but the tool is generic and is usable for other products as well as long as the required concentration data is made available.

Question

How to estimate intakes of chemical compounds in plant-based food supplements and compare them to guidance values?

Answer

The compound intake estimator calculates intakes and levels of health concern of plant-based food supplements based on product-specific concentration data and usage information provided by the user. The tool works online simply with a web browser. For user instructions and some data used, see below.

Compound intakes and risk estimates

A concern indicator is calculated for each compound separately. If the intake is smaller than the threshold of concern, the indicator is < 1 and there is no concern. The threshold of concern is acceptable daily indake (ADI), tolerable daily intake (TDI), lower confidence limit of benchmark dose (BMDL10), or threshold of toxicological concern (TTC), depending on what data is available for each compound.

Compound concentrations

The following code allows to calculate the mean and median value of the concentration of each compound in the input data.

For seeing details of what the code actually does, click Show code. The code will appear, with documentation of each part on rows starting with ###. In brief, the code reads a piece of concentration and other data from Opasnet database, selects the rows defined by the user through the interface above, and shows the data on a summary table and a few graphs.

Rationale

For successful benefit-risk assessment of plant-based food supplements (PFSs), there is a need to estimate intakes of relevant compounds in a product. The health impacts of this exposure are then estimated based on available exposure-response functions. Optimally, all health impacts can be aggregated into e.g. disability-adjusted life years (DALYs) using disability weights or similar importance weights. However, the tool presented here does not go so far. Rather, it compares the intakes of each relevant compound to a guidance value, which is thought to separate safe intakes from non-safe intakes. Non-safe does not mean that the compound is causing health problems; it merely tells about compromised safety margins that are inherently embedded in the guidance values. Small exceedances are most likely harmless, but if the intake is clearly beyond its guidance value, careful consideration of potential risk is warranted.

This web tool, Compound intake estimator, was developed in Plantlibra project to promote the use of quantitative estimates of compound intakes and health risks. The tool consists of open data about guidance values (in the Opasnet database), an open source model (running on R software) to compute intakes and risk estimates, product-specific concentration data that is only partially available, and a user interface where the user can choose modelling options and add case-specific compound concentration data as input to the model. Detailed user guide, and the data and the model are available at http://en.opasnet.org/w/Compound_intake_estimator.

Users who are skilful with R can download the whole model to their own computers and use and develop it further as they please. This requires an R package called OpasnetUtils, which is available from the CRAN repository http://www.cran.r-project.org. It is also possible to develop a new page in Opasnet for a new product and its concentration data. Those who are interested in such work should contact the tool developer Jouni Tuomisto at THL, Finland.

Guidance values

There are several possible approaches for deriving guidance values. In this approach, we use acceptable daily intake (ADI), tolerable daily intake (TDI), lower confidence limit for benchmark dose 10 (BMDL10), and threshold for toxicological concern (TTC). If there are several guidance values available for a single compound, they are used in the preference order mentioned here.

Acceptable daily intake (ADI): An estimate of the amount of a chemical or toxin that a person can ingest daily over a human’s lifetime without appreciable health risk, divided by an average person’s lifespan. The concept of the ADI was developed by the WHO and FAO for chemicals such as additives to foods, pesticide residues and veterinary drugs in foods; ADIs are derived from lab toxicity data and from human experiences of such chemicals when available, and incorporate a safety factor; the ADI is an estimate of the amount of a substance in food that can be ingested over a lifetime by humans without significant risk to health.^[1]

Tolerable daily intake (TDI): Refers to the daily amount of a chemical that has been assessed safe for human being on long-term basis (usually whole lifetime). Originally acceptable daily intake (ADI) was introduced in 1961 to define the daily intake of a food additive which, during the entire lifetime, appears to be without appreciable risk. For contaminants and other foreign chemicals not used intentionally, the term TDI is often preferred.^[2]

Lower confidence limit for benchmark dose 10 (BMDL10): For the dose-response function of a health impact, it is possible to estimate the dose that causes on average 10 % response compared with the highest achievable response. This is called the benchmark dose (BMD10). BMDL10 is the lower confidence limit of BMD10, typically the 2.5th percentile of the probability distribution of the BMD10 estimate.^[3]

Threshold for toxicological concern (TTC): According to the TTC concept, a "safe" level of exposure can be identified for many chemicals based on their chemical structure and the known toxicity of chemicals that share similar structural characteristics. The TTC approach is exclusively designed as a substitute for substance-specific information in situations where there is limited or no information on the toxicity of the compound and information on exposure indicates that human exposure is very low.^[4]

If a compound in a PFS does not have any information on these guidance values, it is ignored in this analysis. The same happens to compounds that exist in the compound but do not have any concentration information.

Intake and guidance value calculations

The total intake of essential oil is calculated like this:

intake_oil = amount_suppl * fraction_oil + amount_oil

where

intake is the total intake of essential oil
amount_suppl is the intake of food supplement
fraction_oil is the fraction of essential oil in the food supplement
amount_oil is the intake of the essential oil consumed directly, i.e. in addition to what is in the food supplement.

The intakes of individual compounds are calculated like this:

intake_comp (mg /kg /d) = intake_oil (g /d) * conc_comp (mg /g) / 60 (kg)

where

intake_comp are the intakes of each compound
intake_oil is the total intake of essential oil
conc_comp are the concentrations of each compound in the essential oil.
60 kg is the assumed body weight of the person

The concern indicator is calculated like this:

concern indicator_comp = intake_comp (mg /kg /d) / guidance value_comp (mg /kg /d) * safety factor_i

where

concern indicator_comp are the preferred indicators for each compound,
guidance value_comp are the guidance values for each compound,
safety factor_i are the safety factors used for each indicator (10000 for BMDL10, 1 for others)

The concern indicator is calculated for each compound separately. If the intake is smaller than the guidance value, the indicator is < 1 and there is no concern. Only one guidance value is used for each compound, the preference order is explained in the previous section. For BMDL10, the typical approach is to divide BMDL10 by the intake and interpret values > 10000 as safe. However, it would be confusing for the user to treat one guidance value differently. Therefore, this tool applies the same equation to all guidance values and uses 10000 as the default safety factor for BMDL10. For all other guidance values, the default safety factor is 1, because they already have embedded safety factors for interspecies and intraspecies variation.

User interface

You can fill in the following information:

Name of plant food supplement (PFS) product. If this is given, it is shown on the graphs and outputs as title.
Fraction of essential oil in the supplement. How much (as a percentage) does the total product contain the essential oil?
Amount of supplement per day. How much is the supplement (the total product) consumed per day (given as grams of product per day)?
The compound concentration data is taken from a table in the Opasnet database. However, if you know that the product contains something that is not listed in the table, you may add the information here.
- Name of additional compound. The name is used to combine the concentration data with toxicological data. So, the name should be found in one of these two tables on this page: Cramer classes of compounds, or Guidance values. If the name is not found, the new piece of information is ignored.
- Concentration of the additional compound in the supplement. This is given as mg of compound per g of PFS product.
- Technical note: You should enter the name of a single compound between quotation marks, e.g. 'Estragol'. If you add several compounds, you should use vector formatting for R, e.g. c('Estragole', 'Fenchone'). The concentration value can be without quotation marks unless it is a distribution or a vector. Acceptable entries for concentrations are e.g. 2.1, '21.4-24.5' and c('2.1', '21.4-24.5').
Show intermediate results? If Yes is selected, you will see two tables of concentration and intake estimates for each compound. Otherwise, only a default output is shown (see below).
Which extraction techniques to consider? Different extraction methods result in different concentration estimates even from the same product. Some of the toxicological information is given having a particular extraction method in mind, and it is not always possible to use toxicological information with any concentration information. Therefore, if you know that some extraction methods should not be used to estimate toxicology, you can unselect them from the list. The default is to use all data, but you can select Yes, let me choose to the extraction techniques, and then select from the list that appears.
The default outcome shows a table and a graph where the level of concern is shown for each compound. However, because there are dozens of compounds in any product, the graph shows only those which has the level more than one, i.e. those compounds that need further scrutiny.

Concentrations

The concentration code allows to calculate the mean and median value of the concentration of each compound that appear in table. In addition, it is possible to plot the concentration (expressed as percentage of essential oil) of each compound reported in the data table. Each single value is reported in the chart.

Data

This is an example data to show what kind of information is used by the tool. It is also used to calculate the example results. Some of the actual data for PFSs is proprietary and is currently only available to the partners of the Plantlibra project.

Example data(%)
Obs	Extraction.technique	Compound	Result	Reference
1	Superheated water extraction, 100 °C	2-Carene	0.08; 0.1; 0.12	Jayawardena & Smith, 2010
2	Superheated water extraction, 100 °C	Z-Cinnamaldehyde	1.63; 2.1; 2.57	Jayawardena & Smith, 2010
3	Superheated water extraction, 100 °C	Cinnamaldehyde	81.14; 83.7; 86.26	Jayawardena & Smith, 2010
4	Superheated water extraction, 100 °C	Eugenol	0.45; 0.8; 1.15	Jayawardena & Smith, 2010
5	Hydrodistillation	1,8-Cineole	0.2	Chericoni et al, 2005
6	Superheated water extraction, 100 °C	Cinnamyl acetate	5.47; 7.2; 8.93	Jayawardena & Smith, 2010

Calculations

This is the code for the actual compound intake estimator model. You need to run the code below only if you update the guidance value tables on this page.

+ Show code - Hide code


library(OpasnetUtils)

################## PRE-DEFINED INPUTS

# compound.conc is the concentration of a compound in the critical constituent (or food, if fr.const == 1) 
# fr.const is the fraction of the critical constituent in the whole food
# extraction is a criteria to select specific extraction techniques
# addcomp is an additional compound not in the product. Data about its concentration in food is given by the user.

# compound.intake is the intakes of the compounds via food or food supplement, each given as mg /kg /d.

compound.intake <- Ovariable("compound.intake", 
	dependencies = data.frame(Names = c(
		"food.amount", # amount of food supplement consumed
		"compound.conc", # concentration of compounds in essential oil
		"oil.amount", # amount of essential oil consumed in addition to the supplement product
		"fr.const", # fraction of essential oil in the supplement product
		"extraction", # Which extraction methods the user wants to consider
		"addcomp" # concentrations of compounds in the essential oil (missing from default data)
		# conc is the temporary ovariable for compound.conc used in calculations
	)), 
	formula = function(...) {

		conc <- compound.conc * 10 * extraction 
		# remove extractions that are not considered.
		# compound.conc from w/w% to mg/g

#		oapply would be an alternative to remove extra indices, but there is a bizarre error.
#		compound.conc <- oapply(compound.conc, cols = "Extraction.technique", fun = mean)

		test <- colnames(conc@output) != "Extraction.technique"
		conc@marginal	<- conc@marginal[test]
		conc@output 	<- conc@output[test] # unit: mg /g
		# removes index Extraction.technique, which is no longer needed.

		conc@output <- orbind(conc, addcomp * 1)
		# addcomp must not contain columns that are not in conc. It must contain Compound.
		# It is multiplied by 1 to make the result column name "Result".

		out <- (food.amount * fr.const / 100 + oil.amount) * conc / 60 
		# calculates the oil intake from food supplement and then adds direct oil intake.
		# scale to 60 kg person
		# fr.const from % to fraction

		test2 <- unique(out@output$Compound[result(out) > 0]) # remove all compounds where intake = 0
		out@output <- out@output[out@output$Compound %in% test2 , ]

		return(out)
	}
)

# guidance.values is the guidance value (ADI, BMDL10, TTC or similar) for compounds. unit: mg /kg /d
# cramer is cramer classes of compounds (temporary)
# cramer.values are the thresholds of toxicological concern for each Cramer class (temporary)

cramer <- tidy(opbase.data("Op_en6193", subset = "cramer_classes_of_compounds"))
cramer$Result <- NULL
cramer$Guidance <- "TTC" # Threshold for toxicological concern

cramer.values <- tidy(opbase.data("Op_en6193", subset = "cramer_values"))
cramer.values <- merge(cramer, cramer.values)
cramer.values[["Cramer class"]] <- NULL
cramer.values$Result <- cramer.values$Result / 1000 # from ug /kg /d to mg /kg /d

guidance.values <- tidy(opbase.data("Op_en6193", subset = "guidance_values"))
guidance.values <- orbind(cramer.values, guidance.values)
guidance.values <- Ovariable("guidance.values", data = guidance.values)

safety.factor <- Ovariable("safety.factor", ddata = "Op_en6193.safety_factors") #  [[Compound intake estimator]]

# food.risk calculates "hazard quotients" or risks relative to guidance values. Value < 1 are of minimal concern

food.risk <- Ovariable(name = "food.risk",
	dependencies = data.frame(Name = c("compound.intake", "guidance.values", "safety.factor")),
	formula = function(...) {

		# guidance.risk is intake compared with guidance values.

		out <- compound.intake / (guidance.values / safety.factor)

		removepoorguidance <- function(dat, goodg) { # Remove inferior guidance values

			# Compounds that have good guidance values (goodg).
			hasgoodg <- unique(dat[dat$Guidance == goodg , "Compound"])

			# The row contains data about a chemical with a good guidance value
			# but the data is about an inferior guidance value.

			out <- dat[!(dat$Compound %in% hasgoodg & dat$Guidance != goodg) , ]

			return(out)
		}

		out <- removepoorguidance(out@output, "ADI")
		out <- removepoorguidance(out, "TDI")
		out <- removepoorguidance(out, "BMDL10")

		test2 <- unique(out$Compound[out$Result > 0]) # remove all compounds where risk = 0
		out <- out[out$Compound %in% test2 , ]

		return(out)
	}
)

extraction <- Ovariable("extraction", ddata = "Op_en6193.extraction_techniques")
extraction@data$extractionResult <- 1

### Define formatting for the concentration graphs that will be shown.

concplot <- function(condition) {
	dat <- compound.conc@output[condition, ]
	if(nrow(dat) != 0) {
		out <- ggplot(dat, 
			aes(
				x = Compound, 
				y = compound.concResult, 
				colour = Extraction.technique
			)) + 
			geom_point(size=5) +
			theme_grey(base_size = 24) +
			theme(axis.text.x = element_text(angle = 90, hjust = 1)) + 
			labs(y = "Concentration (%)")
		return(out)
	} else {
		 warning("No data to show")
	}
}

objects.store(compound.intake, guidance.values, food.risk, extraction, concplot, safety.factor)

cat("The following objects were successfully stored:
compound.intake, guidance.values, food.risk, extraction, concplot, safety.factor\n")

Using different data on different layers: [4].

Extraction techniques

Extraction techniques(-)
Obs	Extraction.technique	Notes
1	Not known
2	Hydrodistillation
3	Solvent extraction
4	Steam distillation
5	Supercritical fluid extraction, 120 bar, 40 °C
6	Supercritical fluid extraction, 90 bar, 40 °C
7	Supercritical fluid extraction, 90 bar, 50 °C
8	Superheated water extraction, 100 °C
9	Superheated water extraction, 150 °C
10	Superheated water extraction, 200 °C
11	Solid phase

Data about guidance values

Generic data about guidance values

Safety factors(-)
Obs	Guidance	Safety factor
1	ADI	1
2	BMDL10	10000
3	TDI	1
4	TTC	1

Cramer values(µg /kg-BW /d)
Obs	Cramer class	Threshold of toxicological concern	Description
1	1	30
2	2	1.5
3	3	1.5
4	4	0.0025	This comes from Apiole?! Is this correct?

Values 30 and 1.5 µg /kg /d come from EFSA (2012)^[5]

Compound-specific data about guidance values

^[6]

Guidance values(mg /kg-BW /d)
Obs	Compound	Guidance	Result	Notes
1	1,8-Cineole	ADI	2.8
2	4-Terpineol	ADI	1.2
3	Benzylbenzoate	ADI	5
4	Cinnamaldehyde	ADI	0.7
5	Coumarin	TDI	0.1
6	Estragole	BMDL10	3.3-6.5	Data said BMD10 but this is BMDL10 (confirmed by Antonella 9th April)
7	Eugenol	ADI	2.5
8	Fenchone	ADI	10.64
9	Limonene	ADI	1
10	Linalool	ADI	0.5
11	Myrcene	ADI	2.5
12	Trans-anethole	ADI	2
13	Safrole	BMDL10	1.9-5.1
14	α-Terpineol	ADI	1.2

Cramer classes of compounds

Cramer classes of compounds(-)
Obs	Compound	Cramer class	Notes
1	1,8-Cineole	3	A new line was created for 1.8-Cineole based on "ß-Phellandrene + 1,8-Cineole: 1+3"
2	2-Carene	1
3	2-Methoxycinnamaldehyde	1
4	3-Phenylpropyl acetate	1
5	4-Methoxyphenylacetone	1
6	4-Terpineol	3
7	Allo-ocimene	1
8	Apiole	4	This is 0.0025 ug/kg/d!? Is this Cramer class at all?
9	Aromadendrene	1
10	Aromatic compound		Class could not be assigned
11	Benzaldehyde	1
12	Benzenepropanal	1
13	Benzenepropanol acetate	1
14	Benzenepropanol	1
15	Benzylbenzoate	1
16	Borneol	1
17	Cadinene	1
18	Calamenene	2
19	Camphene	1
20	Camphor	3
21	Carvacrol	1
22	Carveol isomere	1	Carveol (2-methyl-5-prop-1-en-2-ylcyclohex-2-en-1-ol) is 1. Isomere is not specified so the class was assigned to the general compound
23	Caryophyllene alcohol	3
24	Caryophyllene oxide	3
25	Caryophyllene	1
26	Chavicol	1
27	Cinnamaldehyde	1
28	Cinnamic acid	1
29	Cinnamyl acetate	1
30	Cinnamyl alcohol	1
31	Cis-anethole	2
32	Cis-limonene oxide	2
33	Cis-P-menth-2-en-1-ol	3
34	Cis-sabinene hydrate	2
35	Cis-ß-Ocimene	1
36	Cis-α-ocimene	1
37	Cis-β-ocimene	1
38	Coumarin	3
39	Cryptone	2
40	Cymene isomere	1	cymene is 1. Isomere is not specified so the class was assigned to the general compound
41	E-Anethole	1
42	e-Cadinene + Pioncarvone		Class could not be assigned
43	E-Cinnamyl acetate	1
44	E-o-Methoxycinnamaldehye	1
45	Epoxy-6.7-Humulene + Mw=220		Class could not be assigned
46	Estragole	1	Test compound, not real value
47	Eugenol acetate	3
48	Eugenol	1
49	Fenchyl acetate	1
50	Humulene epoxide II	3
51	Isoledene	1
52	Limonene	1
53	Linalool	3
54	Methoxy eugenol	3
55	Methyl cinnamaldehyde	1
56	Methyl eugenol	1
57	Monoterpenes		Class could not be assigned
58	N-Hexadecanoic acid	1
59	N-Octadecanoic acid	1
60	o-Cymene	1
61	p-Anisaldehyde	1
62	Para-Methoxy cinnamic aldehyde	1
63	p-Cymene	1
64	P-Cymene-8-ol	3
65	Phenyl cyclohexene	2
66	Phenylmethyle isovalerate	1
67	Rutin	1	Test compound, not real value
68	Sabinene	1
69	Safrole	3
70	Sesquiterpene epoxide		Class could not be assigned. Sesquierpene is class 3, but don't now if something changes with epoxide
71	Sesquiterpenol Mw=220		Class could not be assigned
72	Sesquiterpenol Mw=222		Class could not be assigned
73	Spathulenol	3
74	ß-Bisabolene	1
75	ß-Cubebene	1
76	ß-Elemene	1
77	ß-Myrcene	1
78	ß-Phellandrene	1	ß-Phellandrene + 1,8-Cineole: 1+3
79	ß-Pinene	1
80	Styrene	1
81	Terpinen-4-ol	3
82	Terpinolene isomere	1	terpinolene is 1 , isomere not known. Isomere is not specified so the class was assigned to the general compound
83	Terpinolene	1
84	Tetradecanal	1
85	Trans-2-methoxycinnamaldehyde	1
86	Trans-limonene oxide	2
87	Trans-pinene hydrate	2
88	Trans-Pinocarveol	1
89	Trans-Piperitol	1
90	Trans-P-menth-2-en-1-ol	3
91	Trans-ß-Ocimene	1
92	Z-Cinnamaldehyde	1
93	α-Cadinol	3
94	α-Calacorene	2
95	α-Copaene	1
96	α-Cubebene	1
97	α-Famesene		Class could not be assigned
98	α-Gurjunene	1
99	α-Humulene	1
100	α-Muurolene	1
101	α-Muurolol	3
102	α-P-Dimethylstyrene	1
103	α-Phellandrene	1
104	α-Pinene	1
105	α-Selinene	1
106	α-Terpinene	1
107	α-Terpineol	3
108	α-Thujene	1
109	β-Anise aldehyde	1
110	β-Phellandrene	1
111	β-Pinene	1
112	γ-Cadinene	1
113	γ-terpinene	1
114	γ-Terpinene	1
115	Δ3-Carene	1
116	δ-Cadinene	1

References

↑ Segen's Medical Dictionary. 2012 Farlex, Inc. [1] accessed 15th April, 2014.
↑ Wikipedia: [[:en:Tolerable daily intake|]] accessed 15th April 2014
↑ U.S.EPA: Benchmark Dose (BMD) Methodology [2] accessed 15th April, 2014.
↑ Opinion on the Use of the Threshold of Toxicological Concern (TTC) Approach for Human Safety Assessment of Chemical Substances with focus on Cosmetics and Consumer Products. European Union (2012) SCCP/1171/08. [3] acessed 15th April 2014.
↑ EFSA (2012). Scientific Opinion on Exploring options for providing advice about possible human health risks based on the concept of Threshold of Toxicological Concern (TTC). EFSA Journal 2012;10(7):2750
↑ New data obtained from Antonella Guzzon, personal communication (email) 31 March 2014.

[1] Segen's Medical Dictionary. 2012 Farlex, Inc. [1] accessed 15th April, 2014.

[2] Wikipedia: [[:en:Tolerable daily intake|]] accessed 15th April 2014

[3] U.S.EPA: Benchmark Dose (BMD) Methodology [2] accessed 15th April, 2014.

[4] Opinion on the Use of the Threshold of Toxicological Concern (TTC) Approach for Human Safety Assessment of Chemical Substances with focus on Cosmetics and Consumer Products. European Union (2012) SCCP/1171/08. [3] acessed 15th April 2014.

[EFSA_2012-5] EFSA (2012). Scientific Opinion on Exploring options for providing advice about possible human health risks based on the concept of Threshold of Toxicological Concern (TTC). EFSA Journal 2012;10(7):2750

[6] New data obtained from Antonella Guzzon, personal communication (email) 31 March 2014.

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@@ Line 365: / Line 365: @@
 The intakes of individual compounds are calculated like this:
-  intake<sub>comp</sub> = intake<sub>oil</sub> * conc<sub>comp</sub>
+  intake<sub>comp</sub> (mg /kg /d) = intake<sub>oil</sub> (g /d) * conc<sub>comp</sub> (mg /g) / 60 (kg)
 where
@@ Line 371: / Line 371: @@
 * intake<sub>oil</sub> is the total intake of essential oil
 * conc<sub>comp</sub> are the concentrations of each compound in the essential oil.
+* 60 kg is the assumed body weight of the person
-The generic equation above looks like this when the units and constants used are included:
+The concern indicator is calculated like this:
+ concern indicator<sub>comp</sub> = intake<sub>comp</sub> (mg /kg /d) / guidance value<sub>comp</sub> (mg /kg /d) * safety factor<sub>i</sub>
- compound intakes = oil intake (g /day) * concentration of each compound in the oil (mg /g) / 60
+where
-     (60 kg is the assumed body weight of the person)
+* concern indicator<sub>comp</sub> are the preferred indicators for each compound,
+* guidance value<sub>comp</sub> are the guidance values for each compound,
- concern indicator = compound intakes (mg /kg /d) / guidance values for the compounds (mg /kg /d) * safety factor
+* safety factor<sub>i</sub> are the safety factors used for each indicator (10000 for BMDL10, 1 for others)
-The concern indicator is calculated for each compound separately. If the intake is smaller than the guidance value, the indicator is < 1 and there is no concern. For BMDL10, the typical approach is to divide BMDL10 by the intake and interpret values > 10000 as safe. However, it would be confusing for the user to treat one guidance value differently. Therefore, this tool applies the same equation to all guidance values and uses 10000 as the default safety factor for BMDL10. For all other guidance values, the default safety factor is 1, because they already have embedded safety factors for interspecies and intraspecies variation.
+The concern indicator is calculated for each compound separately. If the intake is smaller than the guidance value, the indicator is < 1 and there is no concern. Only one guidance value is used for each compound, the preference order is explained in the previous section. For BMDL10, the typical approach is to divide BMDL10 by the intake and interpret values > 10000 as safe. However, it would be confusing for the user to treat one guidance value differently. Therefore, this tool applies the same equation to all guidance values and uses 10000 as the default safety factor for BMDL10. For all other guidance values, the default safety factor is 1, because they already have embedded safety factors for interspecies and intraspecies variation.
 === User interface ===

Compound intake estimator: Difference between revisions

Revision as of 09:16, 16 April 2014

Contents

Question

Answer

Compound intakes and risk estimates

Compound concentrations

Rationale

Guidance values

Intake and guidance value calculations

User interface

Concentrations

Data

Calculations

Extraction techniques

Data about guidance values

See also

References

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