diff --git a/R/example_code.R b/R/example_code.R
new file mode 100644
index 0000000..c290fa1
--- /dev/null
+++ b/R/example_code.R
@@ -0,0 +1,94 @@
+# filter_dt() -----------------------------------
+taxa.dt = stx_taxa()
+colnames(taxa.dt) # inspect column names to filter for
+
+# Specify taxonomy columns for which tax filtering can be applied.
+# Make sure that list names match the column names in your data table!
+var_ls = list(
+  family = "Cyprinidae",
+  genus  = c("Daphnia","Ceriodaphnia")
+)
+
+tax.out = filter_dt( taxa.dt, var_ls, silent = FALSE)
+View(tax.out) # inspect the output
+
+
+# stx_query() ---------------------------------
+
+# Example 1) - Basic stx_query() call
+# will return results filtered for default endpoint_group = c("XX50", "NOEX", "LOEX") and duration_unit = "h"
+dt = stx_query(verbose = T)
+
+# If you wish to filter for different endpoint groups, you can specify them in the query.
+stx_catalog()$endpoint_group # to view available endpoint groups
+dt1 = stx_query(endpoint_group = c("Bioconc","MATC","MCIG"))
+
+# if you wish to keep all duration_unit and endpoint_groups, set them to NULL. 
+dt2 = stx_query(duration_unit = NULL, endpoint_group = NULL, verbose = T) 
+# including "NR" (not reported) values. This is everything you can retrieve via stx_data() as well. 
+dt3 = stx_query(duration_unit = NULL, endpoint_group = NULL, verbose = T, rm_na = F) 
+
+
+# Example 2) - Filter for specific taxonomic groups
+# Filter for fish and algae for an exposure duration of 12 to 120 hours and concentration unit in g/l for endpoint group XX50 (50% effect/lethality values)
+stx_catalog()$group # to get an idea about available taxonomic groups
+stx_catalog()$concentration_unit
+dt4 = stx_query(
+  verbose = T, 
+  endpoint_group = "XX50",
+  duration = c(12, 120),
+  concentration_unit = "g/l", 
+  tax_group  = c("fish","algae")
+)
+
+
+# Example 3) - Filter for specific genus and chemical compounds + append reference data
+# make sure to extract only EC50/LC50 values from 12 - 96 hours and of comparable concentration units
+dt5 = stx_query(
+  verbose = T,
+  cas_number = c("1071-83-6","63-25-2","138261-41-3"), # glyphosate, carbaryl and imidacloprid 
+  endpoint_group = "XX50", # to get only 50% effect/lethality values
+  duration = c(12, 96),
+  concentration_unit = "g/l", 
+  tax_genus = c("Danio","Daphnia","Ceriodaphnia","Chironomus"),
+  include_reference = TRUE
+)
+
+
+# Example 4) - filter for specific taxonomic families and append reference data + more taxonomic lineage information
+stx_catalog()$family # get an idea about which family to use by inspecting the taxa catalog
+colnames(stx_taxa())[-1] # all possible taxonomic columns to extract from stx_taxa()
+
+dt6 = stx_query(
+  verbose = T, 
+  endpoint_group = "XX50",
+  duration = c(12, 120),
+  concentration_unit = "g/l", 
+  tax_family = c("Cyprinidae","Salmonidae","Daphniidae"),
+  tax_columns = c("group","taxon","genus","family","order","class","habitat"), # to get more taxonomic lineage information
+  include_reference = TRUE
+)
+
+
+# Example 5) - Specific data selection
+# get ALL LC50 values for 96 - 120 h of exposure for zebra fish (Danio rerio)
+danio = stx_query(
+  endpoint_group = "XX50",
+  duration = c(96, 120),
+  effect = "mortality",
+  concentration_unit = "g/l",
+  concentration_type = "active ingredient",
+  tax_genus = "Danio",
+  include_reference = TRUE
+)
+
+# get ALL LC50 values for 24 - 48 h of exposure for Daphnia
+dmag = stx_query(
+  endpoint_group = "XX50",
+  duration = c(24, 48),
+  effect = "mortality",
+  concentration_unit = "g/l",
+  concentration_type = "active ingredient",
+  tax_genus = "Daphnia",
+  include_reference = TRUE
+)
\ No newline at end of file
diff --git a/R/standartox.R b/R/standartox.R
index be0332c..aad3924 100644
--- a/R/standartox.R
+++ b/R/standartox.R
@@ -4,8 +4,9 @@
 #' 
 #' @return Returns a list of data.tables containing the downloaded data. 
 #'
-#' @param data_type character; Specify the type of data to download. Can be one of NULL (default, downloads and imports all), "meta.fst", "phch.fst", "refs.fst", "test_fin.fst", "taxa.fst", etc.
+#' @param data_type character; Specify the type of data to download. Select from c("meta", "phch", "refs", "test_fin", "taxa", "catalog"). NULL (default) will download and imports all,
 #' @param dir_out character; Directory to which the downloaded files should be saved. Default is a temporary directory.
+#' @param silent logical; If TRUE, suppresses messages. Default is TRUE.
 #' 
 #' @author Andreas Scharmueller \email{andschar@@protonmail.com}
 #' @author Hannes Reinwald
@@ -18,59 +19,367 @@
 #' }
 #' @noRd
 #' 
-stx_download = function(data_type, dir_out = file.path(tempdir(), "standartox")) {
+stx_download = function(data_type = NULL, dir_out = file.path(tempdir(),"standartox"), silent = TRUE) {
+  
+  # please keep this. Makes it easier to quickly pull everything without the need of having to specify specific 
+  stx_files = c("meta", "phch", "refs", "test_fin", "taxa", "catalog")
+  if(is.null(data_type)){ data_type = stx_files}
   # Check
-  data_type = match.arg(
-    data_type,
-    c("meta", "phch", "refs", "test_fin", "taxa", "catalog"),
-    several.ok = TRUE
-  )
+  data_type = match.arg( data_type, stx_files, several.ok = TRUE )
   
-  # Output directory
-  dir.create(dir_out, showWarnings = FALSE, recursive = TRUE)
+  # Check if the output directory exists, if not create it
+  if (!dir.exists(dir_out)) { dir.create(dir_out, recursive = TRUE) }
   
-  # Find download URLS
   # HACK this has to be done, because doi.org is the only permanent link between versions
   qurl_permanent = 'https://doi.org/10.5281/zenodo.3785030'
   req = httr::GET(qurl_permanent)
   cont = httr::content(req, as = 'text')
-  
-  # Extract all zenodo download links from the content
+  # extract all zenodo download links from the content
   qurl = unique(stringr::str_extract_all(cont, 'https://zenodo.org/records/[0-9]+/files/.+')[[1]])
   qurl = grep("[.]rds|[.]fst", qurl, value = TRUE) # filter for .rsd and .fst files only! 
-  qurl = sub('\">', '', qurl, fixed = TRUE)
-  qurl = grep(qurl, pattern = paste0(data_type, collapse = '|'), value = TRUE) # filter for data_type
+  
+  # Filter for specific data_type if provided
+  if(!is.null(data_type)){
+    # could be one of: "meta.fst","phch.fst","refs.fst","test_fin.fst","taxa.fst", ...
+    regx_str = paste0("/files/", sub("[.]fst$","[.]fst", sub("[.]rds$","[.]rds", data_type)) )
+    regx_str = paste(regx_str, collapse = "|")
+    qurl = grep(regx_str, qurl, value = TRUE)
+  }
   
   # For each link in qurl check if destination file exists and if not download it.
-  l = list()
-  for(URL in qurl){
-    fl = basename(URL)
-    fl_name = sub('.rds|.fst', '', fl) # remove file extension for list name
-
+  stxDb_ls = list() # output list 
+  for(k in qurl){
+    URL = sub('\">','', k)
+    n   = sub("^.+/files/","", URL)
+    if(!silent) message('\nChecking standartox file: ', n)
+    
     # Define destination file path
-    destfile = file.path(dir_out, fl)
+    destfile = file.path(dir_out, n)
     
     # Check if the file already exists
     if ( !file.exists(destfile) ) {
+      if(!silent) message('Downloading standartox ',n,' ...')
       curl::curl_download(url = URL,
                           destfile = destfile,
                           quiet = TRUE)
+      if(!silent) message('Done! Downloaded to:\n', destfile)
     }
+    else { if(!silent) message('File ', n, ' already exists, skipping download.') }
     
+    if(!silent) message('Reading in file:\t', n)
     # Read in the downloaded files based on their extension 
-    sfx = sub("^.+[.]", "", fl)
+    # for .fst: fst::read_fst(); for .rds: readRDS()
+    sfx = sub("^.+[.]","", basename(destfile))
     if( sfx == "fst" ) { 
-      out = fst::read_fst(destfile, as.data.table = TRUE)
+      stxDb_ls[[n]] = try ( fst::read_fst(destfile) )
+      if(!silent) message("Done!\n")
     } else if (sfx == "rds") { 
-      out = readRDS(destfile)
-    } else { 
-      stop("Unknown file format: ", sfx, "Expecting .fst or .rds files.")
-    }
+      stxDb_ls[[n]] = readRDS(destfile)
+      if(!silent) message("Done!\n")
+    } else { warning("Unknown file format: ", sfx, "Expecting .fst or .rds files.\n") }
   }
+  # Return the list of data frames
+  return(stxDb_ls)
+}
+
+
+#' Filter data.table based on a list of variables
+#' 
+#' This function filters a data.table based on specified values in one or more columns. 
+#' It checks for the existence of the specified columns and applies the filters accordingly.
+#' 
+#' @param dt data.table; The data.table to filter.
+#' @param var_ls list; A named list where each element is a vector of values to filter the corresponding column in the data.table. The names of the list should match the column names in the data.table.
+#' @param silent logical; If TRUE, suppresses messages. Default is TRUE.
+#' 
+#' @return Returns a filtered data.table containing only the rows that match the specified values in the columns. If no matches are found, a warning is issued and NULL is returned.
+#' 
+#' @author Hannes Reinwald
+#' 
+#' 
+#' @examples
+#' \donttest{
+#' # Import the standartox taxonomy data table as example
+#' taxa.dt = stx_taxa()
+#' colnames(taxa.dt) # inspect column names to filter for
+#' 
+#' # Specify taxonomy columns for which tax filtering can be applied.
+#' # Make sure that list names match the column names in your data table!
+#' var_ls = list(
+#' family = 'Cyprinidae',
+#' genus  = c('Daphnia','Ceriodaphnia')
+#' )
+#' 
+#' # Filter your taxonomy table for genus and family specified.
+#' tax.out = filter_dt( taxa.dt, var_ls, silent = FALSE)
+#' View(tax.out) # inspect the output
+#' }
+#' 
+#' @noRd
+filter_dt = function(dt, var_ls, silent = TRUE){
+  stopifnot(is.data.frame(dt))
+  stopifnot(is.list(var_ls))
+  data.table::setDT(dt) # Ensure dt is a data.table
   
-  return(out)
+  var_check = !unlist( lapply(var_ls, is.null) )
+  var_check = names( which(var_check) ) # select only those variables that are not NULL
+  
+  # Loop through the variables and filter the taxa.fst data frame 
+  if (length(var_check) > 0) {
+    dt.out = list()
+    
+    for(var in var_check){
+      if(!silent) message("Filtering for variable: ", var)
+      if (var %in% colnames(dt)) { # Check if the variable exists as a column in data table
+        if( !is.null(var_ls[[var]]) ){
+          # Filter the data table based on the specified column and the values in the variable
+          filter_val = var_ls[[var]]
+          dt.out[[var]] <- dt[ dt[[var]] %in% filter_val ]
+          if(nrow(dt.out[[var]]) == 0){ warning( paste("No query matches found for:\t", var) ) } 
+        }
+      } else {
+        warning(paste("Variable", var, "not found in data table. Skipping filter."))
+      }
+    }
+    
+    # Combine results
+    dt.out = unique( data.table::rbindlist(dt.out) )
+    # Check 
+    if( nrow(dt.out) == 0 ) {
+      warning("No query results for the provided ",paste(var_check, collapse = " & "),
+              ". Please check the input values.")
+      return(NULL) }
+    return(dt.out)
+  } else { dt }
 }
 
+
+#' Query Standartox Toxicity Data
+#'
+#' Retrieve and filter toxicity data from the Standartox database (\url{https://doi.org/10.5281/zenodo.3785030}) using chemical, experimental, and taxonomic criteria.
+#'
+#' @param cas_number character; Optional. Vector of CAS numbers to filter chemicals (e.g. \code{c("1071-83-6","63-25-2","138261-41-3")}). Default is \code{NULL} (no filtering).
+#' @param endpoint_group character; Optional. Endpoint group(s) to filter results. All possible endpoint groups can be checked via \code{stx_catalog()$endpoint_group}. Default is \code{c("XX50", "NOEX", "LOEX")}.
+#' @param exposure character; Optional. Vector of exposure types (e.g. \code{"aquatic"}). All possible exposure types can be checked via \code{stx_catalog()$exposure}. Default is \code{NULL}.
+#' @param effect character; Optional. Vector of effect types (e.g. \code{"Mortality", "Growth"}). All possible effect types can be checked via \code{stx_catalog()$effect}. Default is \code{NULL}.
+#' @param duration numeric; Optional. Numeric vector of length two specifying minimum and maximum test duration (in hours), e.g. \code{c(0, 48)}. Default is \code{c(0, Inf)}.
+#' @param duration_unit character; Optional. Filter by duration unit (e.g. \code{"h"} for hours). All possible duration units can be checked via \code{stx_catalog()$duration_unit}. Set to \code{NULL} to keep all. Default is \code{"h"}.
+#' @param concentration_unit character; Optional. Filter by concentration unit (e.g. \code{"g/l"}). All possible concentration units can be checked via \code{stx_catalog()$concentration_unit}. Default is \code{NULL}.
+#' @param concentration_type character; Optional. Filter by concentration type (e.g. \code{"active ingredient"}). All possible concentration types can be checked via \code{stx_catalog()$concentration_type}. Default is \code{NULL}.
+#' @param tax_columns character; Columns of taxonomic information to append to results. All possible columns can be checked via \code{colnames(stx_taxa())}. Default is \code{c("group", "taxon", "genus", "family")}.
+#' @param tax_genus character; Optional. Filter by genus. All possible genera can be checked via \code{stx_catalog()$genus}. Default is \code{NULL}.
+#' @param tax_family character; Optional. Filter by family. All possible families can be checked via \code{stx_catalog()$family}. Default is \code{NULL}.
+#' @param tax_order character; Optional. Filter by order. All possible orders can be checked via \code{stx_catalog()$order}. Default is \code{NULL}.
+#' @param tax_class character; Optional. Filter by class. All possible classes can be checked via \code{stx_catalog()$class}. Default is \code{NULL}.
+#' @param ecotox_grp character; Optional. Filter by one or more ecotoxicological groups. Possible values are \code{"invertebrate"}, \code{"plant"}, \code{"fish"}, \code{"fungi"}, \code{"algae"}, \code{"aves"}, \code{"amphibia"}, \code{"mammalia"}, \code{"reptilia"}, \code{"macrophyte"}. All possible ecotox groups can be checked via \code{stx_catalog()$group}. Multiple entries possible. Default is \code{NULL}.
+#' @param include_reference logical; If \code{TRUE}, append reference information. Default is \code{FALSE}.
+#' @param rm_na logical; If \code{TRUE}, remove rows with "NR" (not reported) values. Default is \code{TRUE}.
+#' @param verbose logical; If \code{TRUE}, print progress messages. Default is \code{FALSE}.
+#' @param ... Additional arguments passed to \code{stx_download}.
+#'
+#' @return Returns a \code{data.table} with filtered Standartox toxicity data.
+#'
+#' @author Hannes Reinwald
+#'
+#' @examples
+#' \donttest{
+#' 
+#' Basic stx_query() call: Will return results filtered for default endpoint_group = c("XX50", "NOEX", "LOEX") and duration_unit = "h"
+#' stx_query(verbose = T)
+#' 
+#' # If you wish to filter for different endpoint groups, you can specify them in the query.
+#' stx_catalog()$endpoint_group # to view available endpoint groups
+#' stx_query(endpoint_group = c("Bioconc","MATC","MCIG"))
+#' 
+#' # Query for a specific CAS number, endpoint group, and tax group(s)
+#' stx_query(
+#'   cas_number = "1071-83-6",
+#'   endpoint_group = "NOEX",
+#'   duration = c(0, 48),
+#'   ecotox_group = c("invertebrate", "fish"),
+#'   tax_family = "Daphniidae"
+#' )
+#' 
+#' # get ALL LC50 values for 96 - 120 h of exposure for zebra fish (Danio rerio)
+#' stx_query(
+#'   endpoint_group = "XX50",
+#'   duration = c(96, 120),
+#'   effect = "mortality",
+#'   concentration_unit = "g/l",
+#'   concentration_type = "active ingredient",
+#'   tax_genus = "Danio",
+#'   include_reference = TRUE
+#' )
+#' 
+#' # get ALL LC50 values for 24 - 48 h of exposure for Daphnia
+#' stx_query(
+#'   endpoint_group = "XX50",
+#'   duration = c(24, 48),
+#'   effect = "mortality",
+#'   concentration_unit = "g/l",
+#'   concentration_type = "active ingredient",
+#'   tax_genus = "Daphnia",
+#'   include_reference = TRUE
+#' )
+#' }
+#'
+#' @export
+#' 
+stx_query = function(
+  ## COMPOUND FILTERING ##
+  cas_number = NULL,
+  ## BASIC TOX DATA FILTERING ##
+  endpoint_group = c('XX50', 'NOEX', 'LOEX'),
+  exposure = NULL,           # character vector
+  effect = NULL,             # character vector
+  duration = c(0, Inf),      # numeric vector 
+  duration_unit = "h",       # character vector; set to NULL if you want to keep all results!
+  concentration_unit = NULL, # character vector
+  concentration_type = NULL, # character vector
+  ## TAXA FILTERING ##
+  tax_columns = c('group', 'taxon', 'genus', 'family'), # Taxonomy columns to append to the query results. DEFAULT: c('tax_group', 'tax_taxon', 'tax_genus', 'tax_family')
+  tax_genus  = NULL, # character vector
+  tax_family = NULL, # character vector
+  tax_order  = NULL, # character vector
+  tax_class  = NULL, # character vector
+  tax_group = NULL, # character vector
+  ## REFERENCE SECTION ##
+  include_reference = FALSE, # Default FALSE
+  rm_na = TRUE, # Default TRUE; if FALSE, keep NR values in the result
+  verbose = FALSE, # Default TRUE; if FALSE, print messages
+  ...){
+  message("Querying Standartox data base ...")
+  
+  # Import stxDb 
+  if(verbose) message("Reading in Standartox Data ...")
+  stx_table = c('test_fin','phch','taxa') # 
+  if(include_reference) { stx_table = unique(c(stx_table,'refs')) }
+  stxDb =  stx_download(data_type = stx_table) #, ...)
+  names(stxDb) = sub("[.]fst$","",names(stxDb)) # FIX
+  
+  # Convert data frame to data table
+  stxDb = lapply( stxDb, function(dt) data.table::setDT(dt) )
+  tox.dt = stxDb$test_fin # final output object. LARGE right after import!
+  stxDb  = stxDb[stx_table[-1]] # dump the largest object! <- hope to save some memory with that.
+
+  # First quick filter steps:
+  # Remove rows where the specified columns contain "NR" <- NA values
+  if(rm_na){
+    if(verbose) message("Removing 'NA' values ...")
+    tox.dt = tox.dt[!grepl("NR", endpoint) & !grepl("NR", duration_unit) ] 
+  }
+  
+  # Quick fix for endpoint values - some contain weird string endings.
+  tox.dt[, endpoint := sub("[/*]+$","", endpoint)]
+  if(!is.null(endpoint_group)){
+    tmp_var = endpoint_group # quick fix
+    tox.dt = tox.dt[endpoint_group %in% tmp_var]
+  }
+  if(!is.null(duration_unit)){
+    tmp_var = duration_unit # quick fix
+    tox.dt = tox.dt[duration_unit %in% tmp_var]
+  }
+  if( nrow(tox.dt) == 0 ) {
+    warning("No query matches found for the provided endpoint_group or duration_unit. Please check the input values.")
+  }
+  
+  # Step 1: Filter for cas_number then merge with toxdata
+  if(verbose) message("Appending chemical information ...")
+  ## Filter chem data for cas_number
+  if(!is.null(cas_number)){
+    stxDb$phch <- stxDb$phch[cas %in% cas_number]
+    if( nrow(stxDb$phch) == 0 ) {
+      warning("No query matches found for the provided CAS numbers. Please check the input values.")
+    }
+    merge(stxDb$phch, tox.dt, all.x = TRUE, by = "cl_id") -> tox.dt
+  } else {
+    merge(stxDb$phch, tox.dt, all.y = TRUE, by = "cl_id") -> tox.dt
+  }
+  suppressWarnings( tox.dt[, c("chem_class","casnr", "cl_id") := NULL] ) # don't need the cl_id column anymore.
+  
+  
+  # Step 2: Filter for taxonomic groups then merge with toxdata
+  if(verbose) message("Appending taxonomic information ...")
+  
+  # Append 'tax_' prefix to the taxonomic columns (except for tax_key)
+  tax_key = "tl_id"
+  tax_col = paste0("tax_", colnames(stxDb$taxa))
+  tax_col[ grep(paste0("^tax_",tax_key,"$"),tax_col) ] <- tax_key # replace tax_key with tl_id
+  colnames(stxDb$taxa) <- tax_col # set new column names
+  tax_columns = paste0("tax_", tax_columns) # append 'tax_' prefix to tax_columns
+  
+  # Select pre-defined columns for output
+  tax.out = stxDb$taxa[, c(tax_key, tax_columns), with = FALSE]
+  # Merge taxonomy data with tox data by tl_id
+  tox.dt = merge(tox.dt, tax.out, all.x = TRUE, by = tax_key)
+  
+  ## Filtering ecotox_grp ##
+  if(!is.null(tax_group)){
+    regstr = paste(tax_group, collapse = "|")
+    tox.dt = tox.dt[ grepl(regstr, tox.dt$tax_group) ]
+    if( nrow( tox.dt ) == 0 ) {
+      warning("No query matches found for the provided tax_group. Please check the input values.")
+      return(NULL)
+    }
+  }
+  ## Filtering tax_columns ##
+  var_ls = list( # Specify taxonomy columns for which tax filtering can be applied
+    tax_class  = tax_class,
+    tax_order  = tax_order, 
+    tax_family = tax_family,
+    tax_genus  = tax_genus
+  )
+  tox.dt = filter_dt( tox.dt, var_ls)
+  if( is.null(tox.dt) ) { return(NULL) } # Check
+  suppressWarnings( tox.dt[, (tax_key) := NULL] ) # don't need the tl_id column anymore.
+  
+  # Step 3: Final Tox data filtering 
+  tox.dt = tox.dt[!is.na(result_id)] # rmv any rows with NA in result_id <- this should not be the case but to be save!
+  # Filter for the selected columns 
+  var_ls = list(
+    concentration_unit  = concentration_unit,
+    concentration_type  = concentration_type, 
+    effect = effect,
+    exposure  = exposure
+  )
+  tox.dt = filter_dt( tox.dt, var_ls )
+  if( is.null(tox.dt) ) { return(NULL) } # Check 
+  
+  # Filter for duration
+  lower = min(duration)
+  upper = max(duration)
+  if (lower != 0 | upper != Inf) {
+    #tox.dt = tox.dt[duration %between% c(lower, upper)] # <- this works only when data.table is loaded
+    tox.dt = tox.dt[duration >= lower & duration <= upper] # <- this works always
+  }
+  
+  # Check
+  if( nrow( tox.dt ) == 0 ) {
+    warning("No query matches found. Please check the input filter values.")
+    return(NULL)
+  }
+  
+  # Step 4: Append references if wanted 
+  if(include_reference){
+    if(verbose) message("Appending reference information ...")
+    tox.dt = merge(tox.dt, stxDb$refs, all.x = TRUE, by = "ref_number")
+    tox.dt[, c("ref_number") := NULL]
+  } 
+  
+  # Step 5: Final Cleanup 
+  # Replace all occurrences of "NR" with NA
+  tox.dt = tox.dt[, lapply(.SD, function(x) {
+    if (is.character(x)) {
+      x[x == "NR"] <- NA  # Replace "NR" with NA for character columns
+    }
+    return(x)  # Return the modified column
+  })]
+  # Filter out the "result_id" column
+  message("Done!\n")
+  return( tox.dt[, c("result_id") := NULL] )
+} 
+
+
 #' Retrieve data catalog
 #' 
 #' Retrieve a data catalog for all variables (and their values) that can be retrieved with stx_query()
@@ -101,14 +410,14 @@ stx_download = function(data_type, dir_out = file.path(tempdir(), "standartox"))
 #' 
 stx_catalog = function(silent = FALSE, dir_out = file.path(tempdir(), "standartox")) {
   if (!silent) message('Retrieving Standartox catalog..')
-  l = stx_download(data_type = 'catalog', dir_out = dir_out)
+  ls = stx_download(data_type = 'catalog', dir_out = dir_out)[[1]]
 
-  return(l)
+  return(ls)
 }
 
 #' Retrieve Standartox toxicity values
 #' 
-#' Retrieve a data.table contianing the Standartox toxicity data
+#' Retrieve a data.table containing the Standartox toxicity data
 #' 
 #' @param silent logical; If TRUE, suppresses messages. Default is FALSE.
 #' @param dir_out character; Directory to which the catalog should be downloaded. Default is a temporary directory.
@@ -123,14 +432,14 @@ stx_catalog = function(silent = FALSE, dir_out = file.path(tempdir(), "standarto
 #' # might fail if there is no internet connection or Zenodo.org not not available
 #' # basic function call
 #' 
-#' l = stx_data()
+#' dt = stx_data()
 #' 
 #' }
 #' @export
 #' 
 stx_data = function(silent = FALSE, dir_out = file.path(tempdir(), "standartox")) {
-  if (!silent) message('Retrieving Standartox data..')
-  out = stx_download(data_type = 'test_fin', dir_out = dir_out)
+  if(!silent) message('Retrieving Standartox data..')
+  out = stx_download(data_type = 'test_fin', dir_out = dir_out)[[1]]
 
   return(out)
 }
@@ -166,7 +475,7 @@ stx_data = function(silent = FALSE, dir_out = file.path(tempdir(), "standartox")
 #' 
 stx_chem = function(silent = FALSE, dir_out = file.path(tempdir(), "standartox")) {
   if (!silent) message('Retrieving Standartox chemical information..')
-  out = stx_download(data_type = 'phch', dir_out = dir_out)
+  out = stx_download(data_type = 'phch', dir_out = dir_out)[[1]]
 
   return(out)
 }
@@ -202,7 +511,7 @@ stx_chem = function(silent = FALSE, dir_out = file.path(tempdir(), "standartox")
 #' 
 stx_taxa = function(silent = FALSE, dir_out = file.path(tempdir(), "standartox")) {
   if (!silent) message('Retrieving Standartox taxa information..')
-  out = stx_download(data_type = 'taxa', dir_out = dir_out)
+  out = stx_download(data_type = 'taxa', dir_out = dir_out)[[1]]
 
   return(out)
 }
@@ -268,7 +577,7 @@ stx_aggregate = function(dat = NULL) {
 #' 
 stx_meta = function(silent = FALSE, dir_out = file.path(tempdir(), "standartox")) {
   if (!silent) message('Retrieving Standartox meta information..')
-  out = stx_download(data_type = 'meta', dir_out = dir_out)
+  out = stx_download(data_type = 'meta', dir_out = dir_out)[[1]]
 
   return(out)
-}
+}
\ No newline at end of file