EFSA guidance document on clustering and ranking of emissions of active substances of plant protection products and transformation products of these active substances from protected crops (greenhouses and crops grown under cover) to relevant environmental compartments : guidance of EFSA.
Date: 2014-06-05
Institutions: European Food Safety Authority
Subjects: European Food Safety Authority, crop production, dangerous substance, dissemination of EU information, food safety, glasshouse cultivation, plant health product, plant health treatment, public health

EFSA Journal 2014;12(3):3615 

GUIDANCE OF EFSA 

EFSA Guidance Document on clustering and ranking of emissions of active 
substances of plant protection products and transformation products of 
these active substances from protected crops (greenhouses and crops grown 
under cover) to relevant environmental compartments1 

European Food Safety Authority 

European Food Safety Authority (EFSA), Parma, Italy2,3 

ABSTRACT 

EFSA  was  asked  by  the  Commission  to  prepare  an  EFSA  Guidance  document  on  clustering  and  ranking  of 
emissions of  active substances of  plant protection products (PPPs) and transformation products of these active 
substances  from  protected  crops  (greenhouses  and  crops  grown  under  cover)  to  relevant  environmental 
compartments.  This  EFSA  Guidance  Document  provides  guidance  for  users  on  how  to  assess  these  emissions 
when performing risk assessments according to Regulation EC no 1107/2009 of the European Parliament and the 
Council.  

© European Food Safety Authority, 2014 

KEY WORDS 

risk assessment, protected crop, covered crop, environmental fate, pesticide, glasshouse, environmental receptor 

1  On request from European Commission, Question No EFSA-Q-2012-00874, approved on 13 March 2014. 
2  Correspondence: pesticides.ppr@efsa.europa.eu   
3  Acknowledgement:  EFSA  wishes  to  thank  the  members  of  the  EFSA  Working  Group  on  Clustering  and  Ranking  of 
Emissions of Plant Protection Products from Protected Crop systems: Ton van der Linden, Adi Cornelese, Jonas Östgren 
and Alberto Pardossi for the preparatory work on this scientific output and EFSA staff: Mark Egsmose, Jose Oriol Magrans 
and Alessandra Caffi (until November 2013) for the support provided to this scientific output. 

Suggested  citation:  EFSA  Guidance  Document  on  clustering  and  ranking  of  emissions  of  active  substances  of  plant 
protection  products  and  transformation  products  of  these  active  substances  from  protected  crops  (greenhouses  and  crops 
grown  under  cover) 
Journal  2014;12(3):3615,  43  pp., 
to 
doi:10.2903/j.efsa.2014.3615 

relevant  environmental 

compartments.  EFSA 

Available online: www.efsa.europa.eu/efsajournal 

© European Food Safety Authority, 2014 

  
 
 
 
 
 
 
                                                      
Emission routes of PPPs from greenhouses and covered crops 

SUMMARY 

A  number  of  EU  Member  States  (MSs) requested  guidance  on  how  to  carry  out  environmental  risk 
assessment of Plant Protection Products (PPPs) emitted from protected crops in response to EFSA‘s 
consultation of Member States. EFSA was asked by the Commission to prepare a Guidance of EFSA 
on clustering and ranking of emissions of PPPs and transformation products of these active substances 
from  protected  crops  (greenhouses  and  crops  grown  under  cover)  to  relevant  environmental 
compartments. This guidance also addresses elements that should be considered in deriving exposure 
scenarios  to  be  used  in  risk  assessment,  for  both  soil-bound  and  soil-less  production  systems  in 
greenhouses following the Panel‘s recommendations (EFSA, 2012a). 

Receptor soil 

For  all  structures  that  can  be  considered  non-permanent,  risk  assessment  for  the  soil  compartment 
should be performed using the approaches for open field. For permanent structures a risk assessment is 
only  necessary  for  persistent  substances  (DT90 >1  year,  according  to  the  Uniform  principles 
(Regulation (EU no 546/2011)). 

Receptor groundwater 

Leaching  to  groundwater  from  protected  crop  systems  may  occur,  depending  on  environmental 
conditions, the construction technology of the system and the substance properties. For all protection 
structures mentioned in Table 1, except walk-in tunnels and greenhouses, it is proposed to use current 
open-field  approaches  for  exposure  of  groundwater.  For  walk-in  tunnels  and  greenhouses,  example 
scenarios are given. 

Receptor air 

For  all  protection  structures  mentioned  in  Table  1  it  is  proposed  to  use  the  current  approaches 
addressing long-range transport according to FOCUS Air (SANCO/10553/2006 Rev 2 June 2008).  

Receptor surface water 

For all structures mentioned in Table 1, except walk-in tunnels, closed buildings and greenhouses, the 
same approach as for open field should be used as the situation is similar to the open field. For walk-in 
tunnels  it  is  proposed  that  the  FOCUS  surface  water  drainage  scenarios  are  used.  For  greenhouses 
drainage,  example  scenarios  are  presented  in  this  guidance.  These  example  drainage  scenarios  also 
account for re-use of condensation water. 

The full listing of the example scenarios can be found on the EFSA website after the finalisation of the 
guidance. 

It is recommended  that representative exposure scenarios  be developed for greenhouses and walk-in 
tunnels with regard to groundwater and surface water and that the example scenarios be replaced by 
these. 

EFSA Journal 2014;12(3):3615 

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TABLE OF CONTENTS 

Emission routes of PPPs from greenhouses and covered crops 

4.1. 

3.1. 
3.2. 
3.3. 
3.4. 
3.5. 

 ............................................................................................................................................. 1 
Abstract 
Summary 
 ............................................................................................................................................. 2 
Table of contents ...................................................................................................................................... 3 
Background as provided by EFSA ........................................................................................................... 4 
Terms of reference as provided by the Commission ................................................................................ 4 
Context of the scientific output ................................................................................................................ 4 
Assessment   ............................................................................................................................................. 5 
1. 
Introduction ..................................................................................................................................... 5 
2.  Details on structures ........................................................................................................................ 7 
Low (mini) tunnel ................................................................................................................... 8 
2.1. 
Plastic shelter .......................................................................................................................... 9 
2.2. 
2.3. 
Net shelter and shade house .................................................................................................... 9 
2.4.  Walk-in tunnel ........................................................................................................................ 9 
Greenhouse ........................................................................................................................... 10 
2.5. 
3.  Receptors ....................................................................................................................................... 11 
Conclusions for receptor section ........................................................................................... 11 
Receptor soil ......................................................................................................................... 12 
Receptor groundwater ........................................................................................................... 13 
Receptor air ........................................................................................................................... 15 
Receptor surface water .......................................................................................................... 16 
4.  Existing and proposed procedures and models .............................................................................. 17 
Existing procedures and models ........................................................................................... 17 
4.1.1.  Receptor soil ..................................................................................................................... 17 
4.1.2.  Receptor groundwater ....................................................................................................... 17 
4.1.3.  Receptor air....................................................................................................................... 18 
4.1.4.  Receptor surface water ..................................................................................................... 18 
Proposed procedures and models .......................................................................................... 19 
4.2.1.  Receptor soil ..................................................................................................................... 19 
4.2.2.  Receptor groundwater ....................................................................................................... 19 
4.2.3.  Receptor air....................................................................................................................... 19 
4.2.4.  Receptor surface water ..................................................................................................... 19 
5.  Assessments for walk-in tunnels and greenhouses ........................................................................ 19 
Receptor air ........................................................................................................................... 19 
Receptor soil ......................................................................................................................... 19 
Receptors groundwater and surface water ............................................................................ 20 
5.3.1.  Soil-bound crops, leaching and drainage scenarios .......................................................... 20 
5.3.2.  Soil-less crops ................................................................................................................... 21 
Conclusion and recommendations .......................................................................................................... 24 
References   ........................................................................................................................................... 25 
Appendices   ........................................................................................................................................... 27 
Appendix A. Example leaching scenario concerning a covered soil-bound tomato crop in Italy .......... 27 
Appendix B.Example drainage scenario concerning a soil-bound chrysanthemum crop in a high-tech 
greenhouse in the Netherlands ............................................................................................................... 31 
Appendix C.Example of a soil-less rose scenario in a high-tech greenhouse in the Netherlands .......... 34 
Appendix D.Tiered approach surface water (SW) with respect to covered crops .................................. 36 
Appendix E. Greenhouse leaching scenario; climate input files ............................................................ 38 
Appendix F. Greenhouse drainage scenario; climate input files (PEARL) ............................................ 39 
Appendix G. Greenhouse surface water scenario; input files for temperature and water streams ......... 40 
Glossary and abbreviations .................................................................................................................... 41 

5.1. 
5.2. 
5.3. 

4.2. 

EFSA Journal 2014;12(3):3615 

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Emission routes of PPPs from greenhouses and covered crops 

BACKGROUND AS PROVIDED BY EFSA 

During a general consultation of Member States, through the Standing Committee on the Food Chain 
and Animal Health, on needs for updating existing Guidance Documents and developing new ones, a 
number of EU Member States (MSs) requested environmental fate and behaviour guidance on how to 
carry out environmental risk assessment of PPPs emitted from protected crops. 

Based  on  the  Member  State  responses  and  the  Opinions  prepared  by  the  PPR  Panel  (EFSA,  2010, 
2012a)  the  Commission  tasked  EFSA  to  prepare  a  Guidance  of  EFSA  on  clustering  and  ranking  of 
emissions  of  PPPs  and  transformation  products  of  these  active  substances  from  protected  crops 
(greenhouses  and  crops  grown  under  cover)  to  relevant  environmental  compartments  in  letter  of  31 
July 2012. EFSA accepted this task in response to the Commission in letter dated 9 October 2012. The 
Commission  requests  this  scientific  and  technical  assistance  from  EFSA  according  to  Article  31  of 
Regulation (EC) no 178/2002 of the European Parliament and of the Council. 

Following public consultations on the Opinion (EFSA, 2012a), Member States and other stakeholders 
requested  ―an  easy  to  use  Guidance  Document”  to  facilitate  the  use  of  the  proposed  guidance  and 
methodology for the evaluation of PPPs according to Regulation (EC) No 1107/2009. 

Once this Guidance Document is delivered, the Commission will initiate the process for the formal use 
of the Guidance Documents within an appropriate time frame for applicants and evaluators.  

TERMS OF REFERENCE AS PROVIDED BY THE COMMISSION 

EFSA,  and  in  particular  the  Pesticides  Unit,  is  asked  by  the  Commission  (DG  SANCO)  to  draft  an 
EFSA Guidance Documents as mentioned below:  

1)  EFSA  Guidance  Document  on  clustering  and  ranking  of  emissions  of  active  substances  of 
PPPs  and  transformation  products  of  these  active  substances  from  protected  crops 
(greenhouses and crops grown under cover) to relevant environmental compartments. 

The EFSA Guidance Documents should respect the science proposed and methodology developed in 
the two adopted PPR opinions mentioned in this document (EFSA, 2010, 2012a). 

EFSA  is requested to  organise  public  consultations on  the  draft  Guidance  Documents,  to ensure  the 
full involvement of Member States and other stakeholders. To support the use of the new guidance, 
EFSA  is  requested  to  organise  training  of  Member  State  experts,  applicants  and  other  relevant 
stakeholders. 

CONTEXT OF THE SCIENTIFIC OUTPUT 

To address the Terms of References as provided by the Commission. 

EFSA Journal 2014;12(3):3615 

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Emission routes of PPPs from greenhouses and covered crops 

ASSESSMENT 

1. 

Introduction 

This  guidance  is  intended  for  the  risk  assessment  the  active  substances  of  plant  protection  products 
(PPPs)  and  their  transformation  products  (metabolites).  Guidance  is  provided  for  when  the  same 
methodology as for open field can be used and be considered representative or conservative, and when 
special approaches are more appropriate. Table 1 shows a summary of the structures and the proposed 
approaches regarding environmental receptors. These are further discussed in section 3.  

Table 1:   Summary of structures and proposed approaches for exposure assessment 

Structure/system 

Groundwater 
(GW) 

Surface water 
(SW) 

Soil 

Air 

Low net shelter 

FOCUS all 9 (a) 

FOCUS all( a) 

FOCUS (a) 

FOCUSAIR (b) 

Low plastic shelter 

FOCUS all 9 (a) 

FOCUS all (a) 

FOCUS (a) 

FOCUSAIR (b) 

Low net tunnel 

FOCUS all 9 (a) 

FOCUS all (a) 

FOCUS (a) 

FOCUSAIR (b) 

Low plastic tunnel 

FOCUS all 9 (a) 

FOCUS all (a) 

FOCUS (a) 

FOCUSAIR (b) 

High net shelter 

FOCUS all 9 (a) 

FOCUS all (a) 

FOCUS (a) 

FOCUSAIR (b) 

High plastic shelter 

FOCUS all 9 (a) 

FOCUS all (a) 

FOCUS (a) 

FOCUSAIR (b) 

Shade house 

FOCUS all 9 (a) 

FOCUS all a) 

FOCUS (a) 

FOCUSAIR (b) 

Closed building 

Not relevant 

Not relevant 

Not relevant 

FOCUSAIR (b) 

Walk-in tunnel 

 Greenhouse 

Example 
leaching 
scenario concerning 
a soil-bound tomato 
crop in Italy (a) 

FOCUS 
D (a) 

scenario 

FOCUS( a) 

FOCUSAIR (b) 

Example  leaching  scenario  (GW)  concerning  a  soil-bound 
tomato crop in Italy (a) 
Example  drainage  scenario  (SW)  concerning  a  soil-bound 
chrysanthemum crop in the Netherlands 
Example scenario (SW) concerning a soil-less cultivation in the 
Netherlands. 
For the receptor soil: assessment only for persistent substances  

FOCUSAIR(b) 

(a):  For further details on these abbreviations and meanings, please see sections 3 and 4.  
(b):  FOCUSAIR (see also EFSA 2007, 2012a), regarding assessment of potential long range transport. 

In EU regulation 1107 (2009), protected crop systems (e.g. greenhouses and cultivations grown under 
cover) are considered as systems which prevent emission of PPPs after application. In article 3 point 
27 of the mentioned EU regulation the following definition is given: 

A ‘greenhouse’ means a walk-in, static, closed place of crops production with a usually 
translucent outer shell, which allows controlled exchange of material and energy with the 
surroundings  and  prevents  release  of  plant  protection  products  (PPPs)  into  the 
environment. 

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Emission routes of PPPs from greenhouses and covered crops 

For  the  purpose  of  this  Regulation,  closed  places  of  plant  production  where  the  outer 
shell  is  not  translucent  (for  example  for  production  of  mushrooms  or  witloof)  are  also 
considered as greenhouses. 

Nevertheless,  there  are  indications  from  research  reports  and  other  literature  (see,  for  example, 
Teunissen, 2005) that emissions occur also in systems commonly recognised as ―greenhouses‖. These 
systems  do  not  fulfil  the  condition  of  preventing  the  release  of  PPPs  into  the  environment  and 
therefore  do  not  fall  under  what  would  be  defined  as  a  ―greenhouse‖  according  to  the  definition  of 
Regulation (EC) 1107/2009. Therefore, it is necessary to clarify under which scenarios the different 
protected crops fall under the definition of greenhouse according to EU regulation and, consequently, 
under the provisions for mutual recognition foreseen in Article 40(c) of that regulation. To this aim, 
and  following  the  request  of  MSs  to  update  guidance  on  how  to  carry  out  environmental  risk 
assessment of PPPs emitted from protected crops, the Commission asked EFSA to develop a Guidance 
Document  on  clustering  and  ranking  of  emissions  of  active  substances  of  PPPs  and  transformation 
products of these active substances from protected crops (greenhouses and crops grown under cover) 
to relevant environmental compartments. 

For  the  development  of  the  EFSA  Guidance  Document  the  Commission  asked  EFSA  to  respect  the 
science proposed and methodology developed in the two adopted Panel on Plant Protection Products 
and their Residues (PPR) opinions on emissions from protected crops (EFSA, 2010, 2012a). 

In the first opinion (EFSA, 2010), a survey of the covered crop systems was given and a classification 
system  for  structures  was  developed  according  to  six  major  groups:  low  (mini)  tunnels,  plastic 
shelters,  net  shelters,  shade  houses,  walk-in  tunnels  and  greenhouses  (low-  and  high-tech  types).  In 
addition, the emission routes and the major receptors were defined in relation to the structure of the 
cover,  the  pesticide  application  method  and  the  soil/soil-less  growing  system.  This  classification 
system is considered useful in describing the huge variability of the sector and is also used throughout 
this opinion. 

The  second  opinion  (EFSA,  2012a)  addressed  potential  emission  routes,  their  relevance  to 
environmental receptors and their ranking. More specifically, the aim of  the  opinion was to identify 
those  situations for  which scenario  development  was useful  and/or  necessary  and  to  prioritise them. 
The approach was according to two aspects: (1) emission and (2) spatial distribution. With regard to 
the  emission  aspect,  estimations  of  emissions  from  selected  covered  crop  systems  to  environmental 
receptors  were  compared  with  emissions  from  open-field  applications.  With  regard  to  the  spatial 
distribution aspect, the distribution of covered cropping systems was compared with that of open-field 
cropping  systems  as  far  as  driving  forces  for  emissions  are  concerned.  In  addition,  the  opinion 
identified models that can be used for calculating emissions from covered crops and major aspects to 
be considered when actually developing scenarios. 

In  the  second  opinion  (EFSA,  2012a),  only  emissions  of  PPPs  applied  to  crops  grown  under  cover 
were discussed. Exposure assessment in the environmental receptors as well as the ecological effect 
assessment  were  not  addressed.  In  the  Panel‘s  earlier  opinion  on  this  subject  (EFSA,  2010),  it  was 
recognised that emissions from covered cropping systems might occur  as a result of removal of crop 
remnants, harvested products, substrates and plastic materials. The PPR Panel did not consider these 
emissions  in  this  opinion  because  most  Member  States  have  dedicated  regulations  on  these  aspects, 
not  related  to  Regulation  1107/2009.  Assessment  with  regard  to  consumers,  occupational  and 
residential exposure was explicitly excluded from opinion as this was not in the mandate. 

In addition to the above, birds and mammals, non-target arthropods (NTAs, including bees) and non-
target  plants  may  be  exposed  and  at  risk  during  and  after  application  of  PPP  to  protected  crops. 
However, it is outside the scope of this guidance to propose methodology in this respect.  

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Emission routes of PPPs from greenhouses and covered crops 

Plant protection products (PPPs) of biological nature 

The  guidance  in  this  document  mainly  concerns  chemical  PPPs,  i.e.  active  substances  and  their 
metabolites.  PPPs  of  biological  nature,  micro-organisms  or  microbial  biological  control  agents 
(mBCAs)  are  also  subject  to  this  Guidance.  However,  no  specific  exposure  models  for  mBCAs  are 
available  so  far  and  the  models  used  in  the  environmental  risk  assessment  proposed  for  use  in  this 
Guidance are not always capable of, or meant for, predicting fate and behaviour of such products in 
the  environment  (e.g.  these  methods  do  not  consider  the  potential  growth  of  micro-organisms  and 
therefore it  cannot  be  guaranteed  that they  provide a  realistic  worst-case  exposure  assessment  when 
applied  to  them).  For  permanent  structures  OECD  (2012)  document  67  (ENV/JM/MONO(2012)1) 
indicates  that  discharge  to  surface  water  should  be  considered.  For  other  active  substances  of 
biological nature, e.g. plant extracts or food or feed additives, this guidance applies in principle, taking 
into account, however, the relevant approaches for these types of active substances as defined in other 
guidance. 

Where  approved  methods  for  risk  assessment  of  mBCAs  exist  for  open-field  applications  and  this 
guidance  indicates  that  open-field  methodology  can  be  used  for  a  specific  application  to  a  covered 
crop, then that method may be used for the specific application as well. For the time being, the use of 
tools  available  for  chemicals  to  estimate  environmental  exposure  to  micro-organisms  should  be 
considered  on  a  case-by-case  basis.  In  such  cases,  sufficient  justification  should  be  provided  to 
demonstrate  that  a  realistic  worst-case  exposure  has  been  assessed.  In  cases  where  only  low 
confidence  can  be  placed  on  such  exposure  assessment,  applicants  should  consider  providing 
additional  experimental  data  that  allow  exposure  to  the  micro-organisms  to  be  addressed.  These 
additional  data  should  be  derived  from  studies  performed  under  realistic  worst-case  conditions 
representative of the proposed agricultural/horticultural practices proposed for the PPP containing the 
micro-organism. Even though mBCAs are not further addressed in this guidance document, it is still 
important to highlight them and to include this brief discussion of them as they play an important role 
in integrated pest management. 

2. 

Details on structures 

Various  kinds  of  structures  are  currently  used  for  protecting  crops,  including  soil  mulching  with 
plastic  or  organic  (e.g.  straw)  material  or  direct  crop  cover  with  non-woven  fabric.  A  technical 
classification  is  proposed  for  protected  crop  systems  by  taking  into  consideration  the  nature  of  the 
emission  routes  for  PPPs  (EFSA,  2010).  The  classification  considers  the  structure  (frame  and 
covering)  as  well  as  the  growing  system,  in  particular  the  possibility  to  grow  plants  in  media  other 
than soil (soil-less culture) and to recycle drainage water (from both soil-bound and soil-less culture) 
in what are named ―closed-loop systems‖. Protection structures may be  categorised also considering 
the accessibility  for  the  workers (i.e. low,  inaccessible tunnels  or  accessible structures  such  as  large 
tunnels  and  greenhouses)  and  whether  they  are  permanent  or  temporary.  The  permeability  of  the 
covering material is another relevant criterion in regard to PPP emissions.  

Based on these criteria, many kinds of protection structures can be identified (Figure 1); however, the 
main categories considered in this guidance document are low plastic tunnels, (high) plastic shelters or 
shade houses, walk-in tunnels and greenhouses (Table 2). 

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Emission routes of PPPs from greenhouses and covered crops 

Figure 1:   Main categories of protection structures (from EFSA, 2010). The main structures focused 
on in this Guidance are shown in black 

Table 2:   Classification criteria and main categories of protection structures 

2.1. 

Low (mini) tunnel 

This is a simple plastic cover generally associated with mulching. It is a temporary cover, in that it is 
removed some weeks before the harvest.  

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Emission routes of PPPs from greenhouses and covered crops 

Figure 2:   Examples of low tunnels (photos: Alberto Pardossi) 

2.2. 

Plastic shelter 

A  plastic  shelter  is  generally  used  for  fruit  crops,  such  as  table  grape  and  strawberries,  in  order  to 
protect  them  against  cold  or  rain  and  to  extend  the  harvest  period.  In  some  cases,  the  cover  is 
discontinuous, that is the shelter is placed only above the crop row. 

Figure 3:    Plastic  shelters  used  for  table  grape  (left)  (photo:  Alberto  Pardossi)  or  soil-grown 
blackcurrant (right) (photo: Adi Cornelese) 

2.3. 

Net shelter and shade house 

A net shelter is used to protect vegetable or ornamental crops from excessive heat and/or light, wind, 
insects and birds; it may have the shape of a tunnel or small greenhouse, the only difference consisting 
of  a  permeable  cover  fabric.  A  shade  house  is  a  shading  net  in  the  shape  of  a  tunnel  or  small 
greenhouse; it is generally used for ornamental crops. 

Figure 4:   Shade house for pot ornamentals in Italy (photo: Alberto Pardossi) 

2.4. 

Walk-in tunnel 

A walk-in tunnel is an unheated structure used for growing plants. It usually consists of a single layer 
of plastic supported by plastic or metal arches or hoops. These structures are large enough to walk in 
and  work  inside,  and  generally  they  are  temporary,  in  that  they  or  their  coverings  are  generally 
removed at the end of cultivation.  

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Figure 5:   Walk-in tunnels for soil cultivation of strawberry (photo: Alberto Pardossi) 

2.5. 

Greenhouse 

A  greenhouse  is  described  as  a  walk-in,  static,  closed  place  for  crop  production  with  a  translucent 
outer  shell  in  Regulation  (EC)  1107/2009.  Greenhouses  can  be  classified  according  to the  geometry 
(e.g.  single  span  or  multi-span)  and  the  material  used  for  the  frame  (wood,  aluminium,  steel  or  a 
combination of them) and the shell (plastic, both rigid pans and films; glass). These structures range in 
size from small sheds to very large buildings. For example, newly built glasshouses in the Netherlands 
may have a cultivation area of up to 10 ha, with an average height of 8 m.  

Following Pardossi et al. (2004), both low- and high-technology greenhouses can be identified. Low-
technology greenhouses have a very simple structure, with plastic covering and poor climate control; 
very  often,  they  lack  a  heating  system.  Vegetables  and  low-value  cut  flowers  are  grown  under  this 
kind of shelter. 

Figure 6:   Examples of low-tech plastic greenhouses: the traditional low-cost ‗parral‘ (left), which is 
widely used in the southern Spanish region of Almeria, and the more innovative pre-fabricated arch-
shaped multi-tunnel (photos: Alberto Pardossi) 

High-technology greenhouses have a metal structure, are covered by plastic (also rigid pans) or glass 
(obviously,  the  term  ‗glasshouse‘  refers  to  this  kind  of  structure)  and  have  an  automatic  climate 
control,  which  may  include  root  zone  heating,  forced  ventilation,  evaporative  cooling,  light 
conditioning  (shading  and/or  artificial  lighting)  and  carbon  dioxide  enrichment.  Soil-less  growing 
systems  are  often  installed  to  maximise  space-use  efficiency  and  minimise  hand  labour.  They  are 
generally  employed  for  high-value  crops,  such  as  out-of-season  vegetables,  cut  flowers  (e.g.  roses), 
pot ornamentals and propagation materials (seedlings, cuttings, ex vitro plantlets, etc.). 

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Emission routes of PPPs from greenhouses and covered crops 

Figure 7:   Examples  of  high-tech  glasshouse  in  Italy  (left)  and  in  the  Netherlands  (right)  (photos: 
Alberto Pardossi) 

3. 

Receptors  

3.1. 

Conclusions for receptor section 

The risk assessment proposed in this section includes and concerns both the active substance as well as 
all, for risk assessment purposes, relevant metabolites of PPPs. With regards to mBCA microbial plant 
protection products (e.g. microorganisms, viruses and fungi), see section 1 for further details. 

Spatial distributions of open structures are considered to be evenly distributed (have no bias) within 
climatic  zones  with  respect  to  both  temperature  and  precipitation.  This  is  approximately  the  same 
assumption as made for open field so the open-field scenarios can be considered representative.  

This is not assumed for greenhouses and walk-in tunnels and the FOCUS scenarios for open field are 
considered  not  to  be  representative  of  these  structures.  Instead,  separate  scenarios  have  to  be 
developed in the future. 

Mulching and direct plastic cover were excluded in the scientific Opinion (EFSA, 2010) and are not 
included in this table. The environmental risk assessment for open fields can be applied. 

Table 3:  

 Summary of structures and proposed approaches for exposure assessment 

Structure/System 

Groundwater 

Surface water 

Soil 

Air 

Low net shelter 

FOCUS all 9 (1) 

FOCUS all (2) 

FOCUS (3) 

FOCUSAIR (4) 

Low plastic shelter 

FOCUS all 9 (1) 

FOCUS all (2) 

FOCUS (3) 

FOCUSAIR (4) 

Low net tunnel 

FOCUS all 9 (1) 

FOCUS all (2) 

FOCUS (3) 

FOCUSAIR (4) 

Low plastic tunnel 

FOCUS all 9 (1) 

FOCUS all (2) 

FOCUS (3) 

FOCUSAIR (4) 

High net shelter 

FOCUS all 9 (1) 

FOCUS all (2) 

FOCUS (3) 

FOCUSAIR (4) 

High plastic shelter 

FOCUS all 9 (1) 

FOCUS all (2) 

FOCUS (3) 

FOCUSAIR (4) 

Shade house 

FOCUS all 9 (1) 

FOCUS all (2) 

FOCUS (3) 

FOCUSAIR (4) 

Closed building 

Not relevant 

Not relevant 

Not relevant 

FOCUSAIR (4) 

Walk-in tunnel 

Example 

leaching  FOCUS 

scenario  FOCUS (3) 

FOCUSAIR (4) 

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11 

 
 
 
Emission routes of PPPs from greenhouses and covered crops 

scenario concerning 
a soil-bound tomato 
crop in Italy (5) 

D (6) 

 Greenhouse 

Scenarios to be developed for receptors soil, surface water and 
groundwater.  See  also  section  5  and  example  scenarios 
provided in Appendices A, B and C. 

FOCUSAIR (4) 

(1):  All nine FOCUS (2000b, 2009) groundwater scenarios: Châteaudun, Hamburg, Jokioinen, Kremsmünster, Okehampton, 
Piacenza, Porto, Sevilla and Thiva according to FOCUS groundwater scenarios in the EU review of active substances, 
Sanco/321/2000 rev.2 and other Sanco documents. 

(2):  All FOCUS (2001) surface water scenarios at Step 3: D1 (Lanna), D2 (Brimstone), D3 (Vredepeel), D4 (Skousbo), D5 
(La  Jailliere),  D6  (Váyia,  Thiva),  R1  (Weiherbach),  R2  (Valadares,  Porto),  R3  (Ozzano,  Bologna)  and  R4  (Roujan) 
according to FOCUS Surface  Water Scenarios in the EU Evaluation Process under 91/414/EEC, SANCO/4802/2001-
rev.2 final (May 2003). 

(3):  PECsoil to be calculated according to soil persistence models and EU regulation (EC) 1107/2009. The final report of the 
work of the Soil Modelling Work group of FOCUS, 29.2.97 is currently under revision and will be superseded by EFSA 
(2015, in prep). 

(4):  PESTICIDES  IN  AIR:  CONSIDERATIONS  FOR  EXPOSURE  ASSSESSMENT,  Report  prepared  by  the  FOCUS 
Working Group On Pesticides in Air (FOCUS Air Group) SANCO/10553/2006 Rev 2 June 2008, (see also EFSA, 2007, 
2012a), regarding assessment of potential long range transport. 

(5):  According to Appendix A. 
(6):  FOCUS drainage scenarios at step 3: D1 (Lanna), D2 (Brimstone), D3 (Vredepeel), D4 (Skousbo), D5 (La Jailliere), D6 
(Váyia,  Thiva)  according  to  FOCUS  Surface  Water  Scenarios  in  the  EU  Evaluation  Process  under  91/414/EEC, 
SANCO/4802/2001-rev.2 final (May 2003). 

3.2. 

Receptor soil 

For  all  structures  that  can  be  considered  non-permanent,  that  are  limited  in  space  and  temporary  in 
time,  risk  assessment  for  the  soil  compartment  should  be  performed  using  the  approaches  for  open 
field. The following assumptions are made for receptor soil:  

  net precipitation is assumed not to be changed/hardly influenced 

temporal pattern and overall precipitation4 pattern across fields is not changed (local changes 
at spots within a field are not considered here) 

  wash-off from crop is not changed (at least not becoming larger) 

temperature is on the average not lower than open field (where average temperature would be 
higher the open field can be considered conservative) 

soil has not been changed (at least %OM is not lower)  

With  regard  to  covered  cropping  systems,  the  PPR  Panel  made  an  earlier  recommendation  not  to 
develop a separate risk assessment methodology for the receptor soil (EFSA, 2010). If the estimation 
of exposure in soil, either inside or outside the covered cropping system, is subsequently required, as a 
first approximation risk assessment methodology for the open field could be applied (EFSA, 2012a), 
taking  into  account  the  boundary  conditions  of  the  covered  cropping  system.  These  boundary 
conditions were addressed in EFSA (2010). 

In the open structures the soil has not been changed or replaced in such way that open field scenarios 
cannot be considered representative. If soil has been amended with organic materials to enlarge soil 
organic matter content, this will lower the pore water concentrations. The open-field approach can be 
applied in this situation as it can be considered protective for open structures. 

4  Water supply in covered crops may be through precipitation (natural) or irrigation (controlled by farmer). In this guidance 
it is assumed that there is no difference in transport processes as long as the water is distributed evenly over the surface.  

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Emission routes of PPPs from greenhouses and covered crops 

For the soil compartment in permanent structures the relevance of a risk assessment for soil may be 
doubted,  as  in  permanent  systems  the  soils  can  hardly  be  considered  similar  to  field  soils.  If  an 
assessment for an outdoor application of a substance results in an acceptable risk, there is no reason to 
assume any difference for the use in protected crops (EFSA, 2010. PROTEA). If the intended use is 
for permanent structures only, the changes to the soil parameters and the soil organism community can 
be considered such that a risk assessment for soil organisms is not relevant. However, for persistent 
substances  (DT90 > 1  year;  Uniform  principles  (Regulation  (EU  No  546/2011))  an  assessment  as  it 
was  for  open  field  is  required  with  regard  to  their  residues,  to  account  for  possible  change  of 
destination  of  the  soil  within  the  structure  in  the  longer  term  (e.g.  if  the  soil  is  removed  and  used 
outside  and/or  the  structure  is  removed).  As  stated  earlier  in  EFSA  (2010,  2012a),  emissions  from 
covered  cropping  systems  that  might  occur  due  to  removal  of  crop  remnants,  harvested  products, 
substrates and plastic materials need not be considered in this guidance because most Member States 
have dedicated regulations on these aspects, not related to Regulation 1107/2009. 

3.3. 

Receptor groundwater 

For  all  protection  structures  mentioned  in  Table  2  except  walk-in  tunnels  and  greenhouses  it  is 
proposed to use current open-field approaches for exposure of groundwater. Leaching to groundwater 
of active substances depends on, among other things, soil properties. Soil properties are considered to 
be  not  different  for  protection  structures.  For  some  other  properties  influencing  risk  and  amount  of 
leaching through soil a more detailed description for comparison is described below. 

The following assumptions are made for all open structures except greenhouses and walk-in tunnels: 

  net precipitation is assumed not to be changed/hardly influenced 

temporal pattern and overall precipitation5 pattern across fields is not changed (local changes 
at spots within a field are not considered here) 

  wash-off from crop is not changed (at least not becoming larger) 

temperature is on the average not lower than open field (where average temperature would be 
higher the open field can be considered conservative) 

  drip irrigation is not covered, as is for open field (EFSA, 2012a, b) 

soil has not been changed (at least %OM is not lower)  

Where  relevant,  it  is  also  assumed  that  over-irrigation  in  excess  of  the  agriculturally  necessary 
irrigation does not occur. This guidance assumes Good Agricultural Practice (GAP) that includes over-
irrigation of about 20% depending of the salinity of the water source (Pardossi et al., 2006; Gallardo et 
al., 2013). Excess over-irrigation may lead to additional leaching.  

Considering the receptor groundwater, the major factors, besides substance properties, influencing the 
risk  of leaching  can  be  considered the amount  of  active  ingredient reaching  the  soil (determined  by 
interception mainly) and the climatic conditions. Looking at the protection structures (Table 3) it can 
be concluded that the amount of active ingredient reaching the soil will be comparable to open field 
for  high  and  low  net  shelters  and  shade  houses.  This  conclusion  is  based  on  the  fact  that  the 
application technique used for the application of the PPP is the same as in open field.  

In low plastic shelters and low net shelters application to the crop by spraying during coverage is not 
considered relevant. Application to soil or seed has zero interception, the same as for field applications 
to soil or seed. After the cover is removed, the situation becomes identical to open field. If the cover is 

5  Water supply in covered crops may be through precipitation (natural) or irrigation (controlled by farmer). In this guidance 
it is assumed that there is no difference in transport processes as long as the water is distributed evenly over the surface.  

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Emission routes of PPPs from greenhouses and covered crops 

put  back  in place after  application, it  is  assumed  that  the  open-field assessment  is conservative.  For 
these  structures  the  changes  in  driving  forces  on  leaching  to  groundwater  are  assumed  to  have  no 
significant effect on leaching, as compared to the open field under otherwise comparable conditions. If 
the  covering  on  the  structure  is  permeable  or  semi-permeable  to  rain,  this  will  supplement  any 
irrigation  and  thus  the  emission  towards  groundwater  is,  most  probably,  not  less  than  the  emission 
under open-field conditions. 

In low tunnels crops are sprayed with PPPs after the temporary folding of the cover (see Figure 8). 

In  the  current  approach  it  is  assumed  that  this  system  is  comparable  to  field  spray  booms  and  the 
interception is the same.  

Figure 8:   Strawberries  under  low  tunnels.  Treatment  of  the  crop  can  be  performed  with  a  spray 
boom when the plastic sheet is  folded as shown on the photo.  Spray boom: a device consisting of a 
pipe  with  nozzles  for  distributing  spray  from  a  container.  It  is  generally  mounted  on  to  the  rear  of 
tractor or quad (photo: Alberto Pardossi) 

In high net tunnels and high plastic tunnels, spray application of PPP to the crop can be comparable to 
spray application in open field. The interception values from the crop will also be comparable to open 
field.  

Leaching  to  groundwater  in  crops  grown  under  cover  will  be  influenced  by  the  amount  of  water 
(rainfall and/or irrigation) reaching the soil after application of PPPs. 

Water supply which in this context means irrigation to covered crops (low plastic tunnels, low plastic 
shelters, net shelters and shade houses (high net shelters) is usually not different from water supply to 
crops in the open field, i.e. via precipitation (EFSA, 2012a). So, for these constructions, no effect of 
water supply on leaching is expected. If there is coverage after application, in some cases water may 
infiltrate at locations where PPPs were not applied.  The open-field approach is therefore  considered 
conservative. The definitions of irrigation and precipitation are given in the glossary. 

Especially for high and low net shelters, and net tunnels, the amount of rainfall reaching the soil can 
be considered to be not different from open field for the purposes of this guidance. Irrigation may be 
restricted to within the structure but will follow the same procedures as irrigation in open field. 

For low plastic shelters and tunnels, the amount of rain reaching the soil could be lower. Furthermore, 
irrigation in low plastic shelters is not considered relevant as long as the cover is present. Irrigation in 
low plastic tunnels could be by drip irrigation. In that case, soil leaching may be subject to so-called 
―fingering‖. Such uneven water supply, via drip irrigation or furrow irrigation, cannot be handled with 
models currently used in risk assessment (EFSA, 2013). However, such watering systems are used not 
only  in  covered  crops,  but  in  open  field  as  well.  Leaching  may  be  affected  in  both  a  positive  (less 

EFSA Journal 2014;12(3):3615 

14 

 
 
Emission routes of PPPs from greenhouses and covered crops 

leaching) and negative (more leaching) sense, depending on the way the PPP is applied. Comparing 
evenly  distributed  water  supply  and  drip  irrigation,  leaching  may  be  higher  up  to  an  order  of 
magnitude  (Leistra,  1985).  Currently  no  models  (generally  accepted  for  risk  assessment  purposes) 
covering this phenomenon  are available. As it may be expected that at a depth of 1 m (groundwater 
level  in  leaching  models)  the  fingering  process  has  smoothed,  potential  leaching  can  be  described 
using an open-field approach. 

For  walk-in  tunnels  and  greenhouses  with  soil-bound  crop,  an  example  scenario  is  provided  for 
leaching to groundwater (see section 5). It is unknown whether this scenario represents realistic worst-
case  conditions.  Notifiers  may  use  this  scenario  to  construct  their  own  scenario  until  representative 
scenarios  have  been  developed  and  accepted  by  competent  bodies.  For  soil-less  cultivation  systems 
leaching to groundwater can be considered not relevant. 

3.4. 

Receptor air 

For  all  protection  structures  mentioned  in  Table  3  it  is  proposed  to  use  the  current  approaches 
according  to  FOCUS  Air  (SANCO/10553/2006  Rev  2  June  2008)  as  far  as  accepted  by  EFSA  (see 
also EFSA 2007,  2012a), specifically assessment of potential long-range transport.  

Using  the  experimental  data  and  taking  into  account  the  potential  uncertainties  of  volatilisation  and 
vapour pressure (VP) measurements, the following conservative values are proposed by the FOCUS 
Air group to establish whether a substance has the potential to reach the air: 

VP ≥ 10–4 Pa (20 °C) for volatilisation from soil and 

VP ≥ 10–5 Pa (20 °C) for volatilisation from plants 

The FOCUS Air group also proposes that a long-range transport trigger of a DT50air in air of > 2 days 
be  used to identify  substances  that require  further evaluation for long-range  transport.  It  is  assumed 
that this trigger refers to transformation only. However, a clear protection goal for active substances 
with  long-range  transport  potential  is  not  provided  in  the  FOCUS  Air  guidance  or  in  regulation 
1107/2009. 

For  plastic  shelters,  net  shelters  and  shade  houses,  the  emissions  to  air  of  active  ingredients  from 
volatilisation and drift can be assumed to be comparable to open field based on the high ventilation 
rate. For low plastic tunnels and low shelters, the crop protection products will not often be applied 
when  the  cover  is  in  place,  hence  the  approach  for  open  field  can  be  used.  If  the  cover  is  removed 
during  application  and  replaced  immediately  after,  the  open-field  approach  can  be  considered 
conservative for the covered crop application. 

For closed buildings as classified in EFSA (2010), data on emissions to air  are scarce. In Regulation 
1107/2009 warehouses are defined areas for post-harvest treatment, for means of treatment of plants or 
plant  products  after  harvest  in  an  isolated  space  where  no  run-off  is  possible.  In  FOCUS  Air  no 
general  recommendation  on  emissions  from  warehouses  is  given  as  there  is  only  one  study  on 
potential air contamination by contact insecticides during and after warehouse fogging. 

For  the  purpose  of  the  Regulation,  closed  places  of  plant  production  where  the  outer  shell  is  not 
translucent (for example, for production of mushrooms or witloof) are also considered as greenhouses 
and not closed buildings. 

Emissions  to  air  from  greenhouse  and  walk-in  tunnel  covered  crop  systems  do  occur,  even  from 
relatively  closed  systems  such  as  greenhouses  (EFSA,  2012a).  The  driving  force  is  the  necessary 
ventilation  of  the  system  and  factors  influencing  the  volatilisation,  e.g.  the  factors  influencing  the 
Henry  coefficient  of  the  substance.  Calculated  emissions  from  greenhouses,  both  high-tech 
greenhouses  in  the  central  zone  and  multi-span  greenhouses  in  the  southern  zone,  indicate  that  the 

EFSA Journal 2014;12(3):3615 

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Emission routes of PPPs from greenhouses and covered crops 

levels might be as high as or higher than for the open field. However, no currently used models are 
available to cover these emissions and, until developed, the open-field approach should be used. 

3.5. 

Receptor surface water 

For all structures except walk-in tunnels, closed buildings and greenhouses, the same approach as for 
open  field  should  be  used  as  the  situation  is  similar  to  the  open  field.  Small  (resulting  in  lower 
emissions)  to  negligible  effects  are  expected  on  emissions  to  air  and  drift  for  plastic  shelters,  net 
shelters  and  shade  houses,  so  current  approaches  for  open  field  can  be  considered  representative  or 
conservative. Nets are known to have an effect on drift deposition on surface water, dependent on the 
mesh. However, as there is large variability in nets, effects in terms of drift reduction will have to be 
assessed on a case-by-case basis until drift reduction values have been established and accepted. Drift 
deposition on surface water can also be lower for shade houses, depending on the structure of the side 
walls  of  the  construction,  but  this  effect  is  probably  small.  Short-range  atmospheric  deposition  to 
surface water is assumed to be not different from open-field use. 

The following assumptions are made for all structures except closed buildings, greenhouses and walk-
in tunnels: 

  net precipitation is assumed not to be changed/hardly influenced 

temporal pattern and overall precipitation6 pattern across fields is not changed (local changes 
at spots within a field are not considered here) 

  wash-off from crop is not changed (at least not becoming larger) 

temperature is on the average not lower than open field (where average temperature would be 
higher the open field can be considered conservative) 

  drip irrigation is not covered, as for open field (EFSA, 2012a, b) 

soil has not been changed (at least %OM is not lower)  

Additionally, with regard to spray-drift the following assumptions are made for all covered structures 
except closed buildings, greenhouses and walk-in tunnels:  

the  distance  to  the  receptor  surface  water  is  not  less,  i.e.  for  respectively  upwards/sideways 
and  downwards  spraying  (which  should  be  known  from  the  application)  there  are  no 
differences in the distance between the surface water and the last row of the crop 

the wind speed during application is not higher 

the boom height above canopy (downwards spraying only) is at least not higher 

the speed of machine during application is not worse with regard to drift 

if applicable, the same drift reducing technology and/or distance to the non-target object (e.g. 
surface water) as for the open field is assumed.  

For  closed  buildings,  volatile  substances  might  be  transported  to  adjacent  surface  water  bodies. 
Outdoor exposure after warehouse use depends on parameters that have not been quantified. FOCUS 
Air  (2008)  gives  no  general  recommendation  on  emissions  from  closed  buildings  and  the  previous 

6  Water supply in covered crops may be through precipitation (natural) or irrigation (controlled by farmer). In this guidance 
it is assumed that there is no difference in transport processes as long as the water is distributed evenly over the surface.  

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Emission routes of PPPs from greenhouses and covered crops 

opinion of EFSA (2010) did not consider this situation. Currently, insufficient information is available 
to address this issue properly. For practical purposes emissions to surface water are not assessed. 

For walk-in tunnels it is proposed that the drainage scenarios in FOCUS surface water step 3 are used. 
In  the  tunnels,  emissions  to  surface  water  are  expected  from  drift  and  drainage.  Run-off  is  not 
considered a major route as the structure will prevent overland flow. It is assumed that the structure 
remains  for  a  prolonged  period  after  application.  The  three  major  characteristics  of  importance  to 
discharge  to  surface  water  via  run-off  are  temperature,  slope  and  rainfall.  As  walk-in  tunnels  have 
higher temperature (which is best case) and are protected from rainfall, the main routes are expected to 
be drift and drainage. Drift in walk-in tunnels may be almost absent if the cover is continuous but may 
be comparable to drift emission from open field when holes are present, or the side walls are rolled up 
(Beulke, 2011). See also section 4.2. Drift can be regarded as negligible when the application method 
is drip irrigation. 

For  greenhouses,  the  relevant  emission  routes  to  surface  water  are  drainage,  condensation  (and  the 
following deposition onto surface water) and discharge of (recirculation) water. Emissions to air from 
greenhouses shortly after application can be reduced if doors and windows are closed and ventilation 
is limited for some time. For volatile substances, deposition on surface water via air can be assessed as 
soon  as  appropriate  guidance  is  available.  Drift  emission  from  greenhouses  is  negligible  when 
openings are closed during application or when the application method is drip irrigation. In soil-less 
cultivation, the main driving factor with regard to emissions to surface water are filter cleaning and the 
necessity to discharge deteriorated nutrient solution; for soil-bound crops it is the amount of supplied 
water. See also section 4.2. 

4. 

Existing and proposed procedures and models 

4.1. 

Existing procedures and models 

In the current risk assessment for active substances in the EU process it has been common practice in 
the past to assume that the emissions to the environment from closed structures such as greenhouses 
and  walk-in  tunnels  can  be  considered  negligible.  In  the  last  years  it  has  become  more  and  more 
common to assume a deposition value of 0.1 % of the dose rate as drift input to surface water (Linders 
and  Jager,  1997).  For  more  open  structures  the  exposure  assessment  in  the  peer  review  process  has 
often been on a case-by-case basis. If the technology of the structure was unclear from the proposed 
table of uses, risk assessment as for open field use was usually considered as a worst case. 

4.1.1.  Receptor soil 

Estimates of PECsoil is made with simple models and calculations according to FOCUS (1997) using 
a step-wise approach. The guideline details methods for estimating initial and time-weighted average 
concentrations of pesticide concentrations in soil following single and/or multiple applications, as well 
as calculations of plateau concentrations.  

4.1.2.  Receptor groundwater 

Estimating concentrations in groundwater is done according to FOCUS (2000b, 2009), in which nine 
groundwater  scenarios  have  been  defined;  these  are  considered  to  be  the  realistic  worst  case  and  to 
collectively represent agriculture in the EU, for the purposes of a Tier 1 EU-level assessment of the 
leaching  potential  of  active  substances  and  their  metabolites.  The  scenario  definitions  are  lists  of 
properties  and  characteristics  which  exist  independently  of  the  simulation  models.  These  scenario 
definitions have also been used to produce sets of model input files. Input files corresponding to all 
nine scenarios have been developed for use with the simulation models PEARL, PELMO and PRZM, 
whilst input files for a single scenario as well as some national scenarios have also been developed for 
the model MACRO. The scenarios as defined do not mimic specific fields, nor should they be viewed 
as  representative  of  the  agriculture  in  the  Member  States  where  they  are  located.  Instead  the  nine 
scenarios should be viewed as representing major agricultural areas in the EU. The nine scenarios are 
Châteaudun, Hamburg, Jokioinen, Kremsmünster, Okehampton, Piacenza, Porto, Sevilla and Thiva. 

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Emission routes of PPPs from greenhouses and covered crops 

4.1.3.  Receptor air 

Although the PPR Panel had reservations regarding some of the methodology proposed (EFSA, 2007, 
2012a),  it  is  proposed  to  use  FOCUS  (2008)  for  estimating  concentrations  of  pesticides  in  air.  This 
document describes a short-range exposure assessment scheme which uses a vapour pressure trigger to 
identify substances of potential concern. The trigger is 10–5
 Pa (at 20 ºC) if a substance is applied to 
plants and 10–4 Pa (at 20 ºC) if the substance is applied to soil. Substances that exceed these triggers, 
and  require  drift  mitigation  in  order  to  pass  the  terrestrial  or  aquatic  risk  assessment,  need  to  have 
deposition following volatilisation quantified and added to deposition from spray drift. Quantification 
is firstly done by modelling; if safety cannot be demonstrated by this means, then further experimental 
data are required. The guidance also recommends a trigger of a DT50  in air of  two  days to identify 
substances  of  potential  concern  for  long-range  transport.  Substances  having  a  longer  DT50  are 
considered  to  require  further  evaluation  to  assess  their  potential  impact  on  the  environment.  It  is 
assumed that this trigger refers to transformation only. 

Medium-range  transport  is  not  included.  No  general  models  that  are  in  common  regulatory  use  for 
assessing the effects of medium and/or long-range transport exist. Also, a specific protection goal for 
the receptor air is not defined. 

4.1.4.  Receptor surface water 

Predicted concentrations in surface water  are calculated according to FOCUS (2001). The procedure 
consists of four steps, whereby the first step represents a very simple approach using simple kinetics, 
and assuming a loading equivalent to a maximum annual application. The second step is the estimation 
of  peak  and  time-weighted  concentrations  taking  into  account  a  sequence  of  loadings,  and  the  third 
step focuses on more detailed modelling taking into account realistic ―worst case‖ amounts entering 
surface  water  via  relevant  routes  (run-off,  spray  drift  and  drainage).  The  last  (4th)  step  considers 
substance loadings as foreseen in Step 3, but it also takes into account the range of possible uses and 
measures to mitigate exposure. The uses are therefore related to the specific and realistic combinations 
of cropping, soil, weather, field topography and aquatic bodies adjacent to fields.  

The models chosen by FOCUS were MACRO for estimating the contribution of drainage, PRZM for 
the  estimation  of  the  contribution  of  run-off  and  TOXSWA  for  the  estimation  of  the  final  PECs  in 
surface waters. The models include 10 scenarios, considered realistic worst case on the basis of expert 
judgement. Collectively, these scenarios represent agriculture across Europe, for the purposes of Steps 
1 to 3 assessments at the EU level. Six of the scenarios characterise inputs from drainage and spray 
drift (―D-scenarios) whilst four characterise inputs from run-off and spray drift (―R-scenarios‖). The 
field sites chosen to represent each scenario are: 

D scenarios: 

D1 

D2 

D3 

D4 

D5 

Lanna 

Brimstone 

Vredepeel 

Skousbo 

La Jailliere 

D6 

Váyia, Thiva 

R scenarios: 

R1  Weiherbach 

R2 

Valadares, Porto 

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Emission routes of PPPs from greenhouses and covered crops 

R3 

R4 

Ozzano, Bologna 

Roujan 

4.2. 

Proposed procedures and models 

Current  scenarios  for  open-field  applications  may  be  too  conservative  for  walk-in  tunnels  and 
greenhouses with respect to risk assessment for soil and especially groundwater and surface water. 

4.2.1.  Receptor soil 

For  closed  buildings  (if  relevant)  and  greenhouses,  the  (top)  soil  may  have  been  altered  such  that 
open-field  procedures  may  not  be  appropriate.  For  these  situations,  it  is  proposed  that  PPP  soil 
concentrations  are  assessed  in  view  of  a  change  of  function  of  the  soil  at  the  location.  In  want  of 
appropriate assessment methodology at the EU level, the procedure as proposed by Van der Linden et 
al.  (2008)  is  proposed  for  persistent  PPP.  The  specific  protection  goals  are  set  at  the  community 
recovery principle two years after the last application and at the ecological threshold principle seven 
years after the last application. 

4.2.2.  Receptor groundwater 

Current risk assessment procedures for the receptor groundwater may be too conservative for walk-in 
tunnels and greenhouses, while they are not applicable to closed buildings.  

It is therefore proposed not to assess impacts on groundwater for closed buildings and to assess impact 
on groundwater for walk-in tunnels and greenhouses using specific scenarios (see also section 5). 

4.2.3.  Receptor air 

It is proposed to use open-field methodology for assessing the impact on air for all applications, except 
so-called  drip  applications.  This  means  that,  for  walk-in  tunnels  and  greenhouses,  deposition  on 
surface water and long-range transport via air is assessed (FOCUS Air, 2008). For drip applications, 
i.e. applications along with the recirculating nutrient solution, the drift emission may be assumed to be 
negligible.  

4.2.4.  Receptor surface water 

Current  scenarios  for  surface  water  may  be  too  conservative  for  walk-in  tunnels  and  greenhouses, 
while other regulation may exist for closed buildings. It is proposed to assess applications in walk-in 
tunnels  and  greenhouses  according  to  the  procedures  proposed  in  section  5  for  these  covered  crop 
situations.  

5. 

Assessments for walk-in tunnels and greenhouses 

5.1. 

Receptor air  

See section 4.1.3, not different from open field. 

5.2. 

Receptor soil  

See also previous section 4.2.1. Open-field methodology is to be used for walk-in tunnels and 
considered not relevant for greenhouses except for persistent substances (DT90 > 1 year; see Uniform 
principles (Regulation (EU No 546/2011)). The latter is considered necessary in view of potential 
change of function of the location where the greenhouse is situated, with assessment for example 
following the methodology as described in Van der Linden et al. (2008). In this respect, soil content is 
estimated with an appropriate model (FOCUS, 2009) and scenario (see, for example, Appendix B) at 
two and seven years after the last application. It is then checked whether community recovery is 
possible after two years and the ecological threshold level is met after seven years. EFSA is currently 
(at the time of the finalisation of this guidance) working on a guidance document (EFSA, 2014, in 

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Emission routes of PPPs from greenhouses and covered crops 

prep.) on assessments for soil which may have impact on current procedures, for open fields and 
covered crops as well.  

5.3. 

Receptors groundwater and surface water 

FOCUS (2000b, 2001, 2009) provides scenarios for groundwater and surface water environmental risk 
assessment for applications of PPPs to open-field crops. Although scenarios are being developed in the 
Netherlands  for  soil-bound  crops  in  greenhouses  (Wipfler  et  al.,  2014  in  prep.),  such  representative 
and generally accepted scenarios do not exist yet at the EU level for greenhouses and walk-in tunnels. 
This section describes what information is required to construct scenarios for these growing systems 
and associated appendices give typical examples of such scenarios. It should be noted, however, that 
their representativeness is not known and therefore they should be regarded as examples only. 

The example scenarios are: 

1.  a leaching scenario for a soil-bound tomato crop at a location in Italy; 

2.  a  drainage  scenario  relevant  for  surface  water  for  a  soil-bound  chrysanthemum  crop  at  a 

location in the Netherlands; 

3.  a soil-less cultivation scenario for a rose crop (cut flower) at a location in the Netherlands with 

discharge to surface water. 

The  example  scenarios  are  described  in  detail  in  the  appendices.  This  section  gives  a  summary 
description and highlights the main information that is required for constructing scenarios. 

5.3.1. 

Soil-bound crops, leaching and drainage scenarios 

The models generally used to calculate leaching and drainage from open-field cultivation can equally 
well be used to calculate leaching and drainage from walk-in tunnels and greenhouses if appropriate 
scenarios  are  available.  As  stated  above,  representative  and  generally  accepted  scenarios  for  risk 
assessment are lacking for soil-bound greenhouse crops, so, for the time being, scenarios have to be 
constructed and their parameterisation justified. For soil-bound crops, leaching can be assessed using 
one  of  the  currently  used  FOCUS  models  (MACRO,  PEARL,  PELMO  and/or  PRZM).  When 
assessing  drainage  to  surface  water,  the  model  should  be  capable  of  handling  preferential  flow 
(MACRO or PEARL). Fate in the surface water can then be assessed using the TOXSWA model. The 
models and background information is available on the FOCUS website http://focus.jrc.ec.europa.eu/. 
Appropriate  scenarios  are  to  be  established/selected  by  the  notifier  and  the  selection  and 
parameterisation is to be justified, until methodology and scenarios are established and approved by 
competent bodies. Example scenarios for these are given in the appendices. 

For  soil-less  cultivations,  assessment  of  leaching  is  considered  not  necessary.  Emissions  to  surface 
water  can  be  estimated  using  the  Greenhouse  Emission  Models  (GEM)  package  (Vermeulen  et  al., 
2010;  Van  der  Linden  et  al  2014,  in  prep.)  until  methodology  and  scenarios  are  established  and 
approved by competent bodies. An example scenario is given in Appendix C. 

A scenario requires specification of crop and soil parameters as well as soil management information 
and  (in-system)  climatic  conditions.  The  following  text  gives  a  short  summary  of  the  required 
information;  further  information  and  examples  are  given  in  Appendices  A  and  B.  The  reader  is 
referred to FOCUS (2000b, 2001, 2009) for full descriptions. Relevant emission routes are leaching 
(for the receptor groundwater) and drainage and occasionally condensation discharge (for the receptor 
surface water). In addition, drift can be taken into account for walk-in tunnels (see also Beulke et al. 
(2011)  and  section  4.2).  In  general,  run-off  will  not  occur  owing  to  the  construction  preventing 
overland flow of water. 

Crop information consists of: 

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crop stage as a function of time, at least dates of emergence (or transplanting date), maximum 
leaf area index (LAI), senescence (canopy closure) and harvest (crop removal); 

the rooting depth and crop height and the value of maximum LAI; 

typical  values  of  the  crop  water  withdrawal  function  (including,  for  example,  the  wilting 
point; for details see page 201 of Appendix E of FOCUS 2000a). 

Soil information consists of: 

soil texture 

soil bulk density 

soil organic matter or soil organic carbon 

soil pH 

soil hydraulic properties 

of all layers (or horizons) of the soil profile. 

Soil management information includes the date(s) of soil tillage and the depth(s) to which the soil is 
tilled. 

The  weather information  should include  at  least  the  temperature  (°C)  inside  the  greenhouse and  the 
amounts  of  irrigation  (mm  water  layer)  in  the  course  of  time,  on  an  hourly  or  daily  basis.  This 
guidance  assumes  application  of  the  PPP  according  to  the  GAP,  which  includes  over-irrigation  of 
about 20 % depending on the salinity of the water source (Pardossi et al., 2006; Gallardo et al., 2013). 
Excess over-irrigation may lead to additional leaching. Information on radiation, humidity, wind speed 
and potential evapotranspiration should be available dependent on calculation options and/or might be 
used to derive the necessary information for the calculations using external models. 

In  principle,  all  necessary  substance  parameters  are  available  from  the  dossier.  Sometimes,  default 
values may be used if substance-specific information is not available, e.g. the plant uptake factor. The 
substance  information  includes  molar  mass,  solubility  in  water,  saturated  vapour  pressure,  sorption 
constant  and  transformation  constants  in  soil  and  water.  Also  available  from  the  dossier  is  the 
substance  application  scheme  (including  the  amount(s)  and  the  time(s)  of  application  or  the  growth 
stage(s) of the crop at which the substance is applied). It may be necessary to translate growth stage(s) 
into calendar information. Relevant EU guidance should be consulted on use in exposure assessment 
of  the  above-mentioned  default  values,  application  scheme  information  and  growth  stage/calendar 
information. 

Appendix  A  gives  an  example  of  a  leaching  scenario  concerning  a  soil-bound  tomato  crop  in  a 
greenhouse  in  Italy.  Appendix  B  gives  a  drainage  scenario  concerning  a  chrysanthemum  crop  in  a 
greenhouse in the Netherlands.  

5.3.2. 

Soil-less crops 

The currently available model for calculating emissions from soil-less cultivations (Vermeulen et al., 
2010; Van  der  Linden  et  al.  2014  in  prep.)  is,  in  fact,  a  combination  of  a  model  for  calculating  the 
water demand of, and water supply to, the crop (the model WATERSTREAMS; Voogt et al., 2012) 
and a model for calculating fate and behaviour of substances in the system and discharge (emission) 
from the system to surface water. The discharge can be input to a surface water simulation model in 
order to calculate exposure concentrations in the surface water. A software package containing GEM 

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Emission routes of PPPs from greenhouses and covered crops 

and TOXSWA has been established and a beta-version of the package is ready for distribution and will 
be made available on www.pesticidemodels.eu. 

Figure 9 gives a schematic representation of a soil-less crop system and the water and substance flows 
in the system. 

Figure 9:   Schematic overview of a soil-less growing system. Source: Voogt et al. (2012) 

The WATERSTREAMS model calculates the crop water demand based on climatic conditions outside 
the  greenhouse  and  greenhouse  management  parameters  such  as  greenhouse  temperature  and 
humidity.  Water  is  taken  from  a  rainwater  storage  basin  or  alternative  water  source  and  pumped 
around in excess of the crop water requirement. In recirculation systems, the excess water is returned 
to  the  fertigation  unit  and  mixed  with  fresh  water  unless  there  is  a  need  for  discharge.  In  non-
recirculating systems, the excess water is discharged directly. Besides flows of water, the model takes 
account of nutrients and salts in the system reservoirs. GEM accounts for PPPs present in the system 
and  calculates  concentrations  in  various  reservoirs  and  degradation  and  uptake  of  PPPs.  PPPs  may 
enter the system via addition to the recirculating water or via application the crop,  e.g. by spraying, 
fogging  or  fumigation.  In  the  latter  situation,  the  PPP  may  enter  the  system  after  partitioning  into 
condensation water, which is collected and added to the recirculating water. 

PPPs may leave the system via air exchange, leakage, filter rinsing and discharge. Under recirculating 
conditions, ions not taken up by the crop may accumulate. The speed of accumulation is dependent on 
the  concentrations  of  these  ions  in  the  water  sources  and  fertilisers  and  the  uptake.  If  concentration 
levels exceed tolerance levels, part of the recirculating is discharged and replenished with fresh water. 
In WATERSTREAMS, discharge is governed by the sodium level of the system. Other management 
decisions may add to the discharge. 

For  the  development  of  a  scenario,  WATERSTREAMS  needs  the  following  major information  (see 
Voogt et al., 2012, for details): 

  Weather conditions of the area (daily or hourly value;, see example). 

  The size of the rainwater storage basin. 

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Emission routes of PPPs from greenhouses and covered crops 

  The sodium concentration in the various water sources, for example rain water near the coast 
0.5 mmol/L,  reverse  osmosis  water  0.1 mmol/L,  tap  water  1.8 mmol/L.  It  is  assumed  that 
rainwater is preferentially used and that other sources are used only when the rainwater basin 
is empty. 

  The sodium concentrations in the fertilisers. 

  Crop  and  its  growth  parameters,  including  the  maximum  sodium  concentration  tolerated  by 

the crop. 

Indoor climatic set points such as minimum temperature. 

  The  drainage  fractions,  i.e.  the  amount  of  water  in  excess  of  the  crop  requirement.  This 
guidance  assumes  the use of  GAP  which implies that  for  recirculation  systems  the  drainage 
fraction is usually between 0.3 and 0.5. For open loop systems over-irrigation is about 10 % to 
20 %  depending  on  the  salinity  of  the  water  source  (Pardossi  et  al.,  2006;  Gallardo  et  al., 
2013). 

  Management information on the filter system and how that is handled. 

  Any  other  information  on  crop  management,  for  example  periods  of  operating  without 

recirculation. 

In order to calculate fate and behaviour of a PPP in the system, the following information needs to be 
available from the dossier or otherwise, for parent and metabolites: 

  Physico-chemical parameters such as molar mass, water solubility, saturated vapour pressure 
and the octanol/water partition coefficient. The latter is necessary to calculate the plant uptake 
of the substance (Briggs‘s method). 

  The sorption constant, Koc (or Kom in the case of dissociating (weak acidic) substances), pKa 
and  the  sorption  constants  for  the  acid  as  well  as  the  conjugated  base.  This  information  is 
necessary only if the substance is applied to pot plants. 

  The  degradation  constant  in  water  or  nutrient  solution.  In  addition,  degradation  constants 
applicable to the water treatment unit can be used by the model. For selection of degradation 
data, see Boesten (2014, in prep.). When available, substance-specific values of the Arrhenius 
activation energy (or Q10 value) can be taken into account. 

For  pot  plant  systems,  the  relative  area  of  the  pots  has  to  be  provided  in  case  of  a  spraying  (or 
equivalent) application. 

Finally, of course, the application scheme, the application amounts and the application method have to 
be  known.  Together  with  the  growth  system,  the  application  method  defines  which  model  options 
apply.  Application  to  the  nutrient  solution  and  spraying  require  different  options,  because  different 
routes of substance flows are taken into account. A third option is available for a spray application to 
pot plants in ebb/flow systems. 

The TOXSWA  model  may  be  used to calculate  exposure  concentrations in surface  water.  A  special 
version is needed because discharge from a greenhouse has to be regarded a point source rather than a 
diffuse source. The information required to run the TOXSWA model is the same as the information 
required for running the open-field applications with the TOXSWA model (see FOCUS, 2001).  

Appendix C gives typical input and set-points for a rose crop in a glasshouse. Total volumes (average 
yearly values of water supply, discharge, etc.) are also given. 

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CONCLUSION AND RECOMMENDATIONS 

EFSA was asked by the Commission to prepare  guidance on clustering and ranking of emissions of 
PPPs  and transformation  products  of these  active  substances from  protected  crops  (greenhouses and 
crops grown under cover) to relevant environmental compartments. This EFSA Guidance Document 
provides  guidance  for  users  on  how  to  assess  these  emissions  when  performing  risk  assessments 
according  to  Regulation  EC  No  1107/2009  of  the  European  Parliament  and  the  Council.  In  this 
Guidance  Document  risk  assessment  methodology  is  assigned  to  all  covered  crop  structures  except 
greenhouses and walk-in tunnels, for which only examples are given.  

EFSA (2012a) identified and classified a number of protected crop systems and identified greenhouses 
and walk-in tunnels as having priority for scenario development. It is recommended to further develop 
representative exposure scenarios for greenhouses and walk-in tunnels with regard to groundwater and 
surface water.  mBCAs of biological nature are also briefly discussed as, according to the  OECD 67 
(2012)  document  (ENV/JM/MONO(2012)1)  on  the  environmental  safety  evaluation  of  microbial 
biocontrol  agents,  discharge  to  surface  water  should  be  considered  for  permanent  structures.  It  is 
therefore recommended that further guidance should be developed to estimate environmental exposure 
from mBCAs from protected crops and for open-field applications.  

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  Available online: http://www.efsa.europa.eu/en/sopporting/pub/151e.htm. 

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FOCUS, 2000b, ―FOCUS groundwater scenarios in the EU review of active substances‖—The report 
of the work of the Groundwater Scenarios Workgroup of FOCUS (Forum for the Co-ordination of 
pesticide  fate  models  and  their  Use),  Version1  of  November  2000.  EC  Document  Reference 
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FOCUS,  2001.  FOCUS  Surface  Water  Scenarios  in  the  EU  Evaluation  Process  under  91/414/EEC 
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SANCO/4802/2001-rev.2, 245 pp. 

FOCUS, 2002. Generic guidance for FOCUS groundwater scenarios, Version 1.1, April 2002, 61 pp. 

FOCUS,  2003.  FOCUS  Surface  Water  Scenarios  in  the  EU  Evaluation  Process  under  91/414/EEC 
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Reference SANCO/4802/2001-rev.2 final (May 2003), 245 pp. 

FOCUS,  2008.  Pesticides  in  air:  considerations  for  exposure  assessment.  Report  prepared  by  the 
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SANCO/10553/2006 Rev.2 June 2008 328 pp. 

FOCUS,  2009.  Assessing  Potential  for  Movement  of  Active  Substances  and  their  Metabolites  to 
Ground  Water  in  the  EU.  Report  of  the  FOCUS  Ground  Water  Work  Group,  EC  Document 
Reference Sanco/13144/2010 version 1, 604 pp. 

Linders  JBHJ  and  Jager  DT  (Eds.),  1997.  USES  2.0,  The  Uniform  System  for  the  Evaluation  of 

Substances, version 2.0; supplement to EUSES. RIVM Rapport 679102037, 216 pp. 

OECD  (Organisation  for  Economic  Cooperation  and  Development),  2012.  Guidance  to  the 
environmental safety evaluation of microbial biocontrol agents, OECD series on Pesticides No. 67. 
ENV/JM/MONO(2012)1. 

Pardossi  A,  Tognoni  F  and  Incrocci  L,  2004.  Mediterranean  greenhouse  technology.  Chronica 

Horticulturae, 44 (2), 28–34. 

Pardossi  A,  Malorgio  F,  Incrocci  L,  Carmassi  G,  Maggini  R,  Massa  D  and  Tognoni  F,  2006. 
Simplified  models  for  the  water  relations  of  soil-less  cultures:  what  they  do  or  suggest  for 
sustainable water use in intensive horticulture. Acta Horticulturae (ISHS), 718, 425–434. 

Teunissen RJM, 2005. Emissies van gewasbeschermingsmiddelen uit de glastuinbouw [Emissions of 
plant  protection  products  from  glasshouses].  Riza  rapport  2005.019,  Riza,  Lelystad,  69  pp.  (in 
Dutch). 

Van der Linden AMA, Boesten JJTI, Brock TCM, van Eekelen GMA, ter Horst MMS, de Jong FMW, 
Montforts MHMM and  Pol JW, 2008. Revised proposal for the risk assessment of persistence of 
plant protection products in soil. Bilthoven, RIVM, report 601712003. 

Van  der  Linden  AMA,  Vermeulen  T,  Ludeking  DJW,  Cornelese  AA,  van  Os  EA  and  Wipfler  EL, 
2014. Scenarios for exposure of aquatic organisms to plant protection products in the Netherlands. 
Soil-less cultivations in greenhouses. Bilthoven, RIVM, report 607407005 (in preparation). 

Vermeulen T, van der Linden AMA, van Os EA. 2010. Emissions of plant protection products from 
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607407001. 

Voogt W, Swinkels G-J, van Os E. 2012. ‗WATERSTREAMS‘: a model for estimation of crop water 
demand, water supply, salt accumulation and discharge for soil-less crops. Proceedings on the IVth 
IS on HortiModel 2012. Eds. Weihong Luo et al. Acta Horticulturae, 957, ISHS 2012. 

Wipfler  EL,  Cornelese,  A,  Tiktak  A,  Vermeulen  T  and  Voogt  W,  2014.  Scenarios  for  exposure  of 
aquatic  organisms  to  plant  protection  products  in  the  Netherlands,  part  3:  Soil-bound  crops  in 
greenhouses, Wageningen, The Netherlands, Alterra, Alterra Report 2388 (in preparation). 

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APPENDICES  

Appendix A.   Example leaching scenario concerning a covered soil-bound tomato crop in Italy 

This  appendix  gives  an  example  scenario  for  leaching  of  substances  to  groundwater.  The 
representativeness of the scenario for the purposes of risk assessment has not been established, either 
for Italy or for the rest of Europe. In order to establish a representative scenario, a proper selection has 
to be performed (EFSA 2012a, b). 

The following sections describe necessary parameters to construct a scenario for soil-bound covered 
crop. Data in the tables and figures pertain to the example. 

The  crop  for  this  scenario  example  is  tomatoes.  Parameterisation  in  this  example  scenario  is  for  a 
single crop grown in one year. Table A1 and Table A2 give the crop parameters. Dates of the various 
growth  stages  have  been  provided  by  A.  Pardossi  (University  of  Pisa,  personal  communication 
November 2013). LAI, root depth and crop Kc-factors are taken from the tomato crop of the Piacenza 
leaching scenario (FOCUS, 2009). Table A3 and Table A4 give the soil parameters. For this scenario, 
soil parameters have been taken from the FOCUS Piacenza leaching scenario (FOCUS, 2009). Table 
A5 gives a summary overview of climatic conditions in the greenhouse. A detailed climate input file is 
provided as separate appendix (Appendix E) to this guidance. 

Figure A1 gives daily temperatures inside and outside a typical greenhouse near Pistoia, Italy, for the 
year 2011. It is clear that the daily average temperature inside the greenhouse is mostly slightly higher 
than the outside temperature during the summer period, but considerably higher in spring and autumn. 
These differences are due to the heating of the systems in the colder periods of the year. Figure A2 
show that, in contrast, the daily global radiation is almost always slightly to substantially lower than 
outside the system. The higher temperature affects the transformation rates of substances. Degradation 
rates will be higher in the greenhouse, which will lead to lower leaching concentrations when only the 
transformation process is considered. 

Figure  A3  shows  measured  actual  evapotranspiration  values  for  an  experiment  with  a  tomato  crop, 
performed  at  the  University  of  Pisa  under  typical  Tuscan  (Italy)  conditions.  The  irrigation 
requirements of the crop were then calculated using the water balance method (Pardossi and Incrocci, 
2011). The calculation assumes that soil moisture in the top 60 cm can be depleted by 15 % without 
causing  water  stress.  Based  on  the  data  in  Table  A4,  this  is  equivalent  to  a  water  layer  of  20 mm 
(rounded).  In  order  to  avoid  salt  accumulation  in  the  soil  and  accounting  for  non-uniform  water 
distribution,  irrigation  amounts  are  usually  between  10 %  (low  salinity)  and  100 %  (high  salinity) 
higher; 20 % was assumed to construct Figure A3. 

The separate Appendix E provides a climate file covering 20 years (plus a 6-year warm-up period) of 
daily  weather  conditions  such  that  a  leaching  calculations  according  to  the  FOCUS  (2000b,  2009) 
procedures can be performed, using one of the standard leaching models PEARL, PELMO or PRZM. 

Table A1 

 Crop parameters of the Italian greenhouse scenario 

Crop 

Growth stage (a) 

Max LAI 

Planting 
(dd/mm) 

Emergence (b) 
(dd/mm) 

Senescence 
(dd/mm) 

Harvest 
(dd/mm) 

(m2/m2) (c) 

(dd/mm) (a) 

Root 
depth (c) 
(m) 

Tomatoes 

– 

18/03 

22/07 

22/08 

6.0 

20/06 

1.0 

(a):  Data provided by A. Pardossi, University of Pisa. 
(b):  Day of transplanting from seedbed. 
(c):  Data from FOCUS (2009), Piacenza tomato crop. 

EFSA Journal 2014;12(3):3615 

27 

 
 
Emission routes of PPPs from greenhouses and covered crops 

Table A2:  Crop Kc-factors of the Italian greenhouse scenario 

Kc factor as a function of cropping periods (a) (expressed in dd/mm–dd/mm) 

Crop 

Harvest to 
emergence (b) 
Period 

Kc 

Emergence to maximum 
LAI 

Maximum LAI to 
senescence 

Senescence to 
harvest 

period 

Kc 

1.05 

Period 

Kc 

Period 

Kc 

20/06–21/07 

1.10 

22/07–22/08 

0.85 

Tomatoes 

23/08–17/03 

1.00 

18/03–19/06 

(a):  After FOCUS (2009); see also parameterisation of the FOCUS leaching scenarios a.o. FOCUS (2000b). 
(b):  Transplantation from seedbed. 

Table A3:  Soil parameter of the Italian greenhouse scenario (after FOCUS 2009) 

Texture (%) 

Horizon  Depth (cm)  Classification 

pH 
(H2O) (a) 

pH 
(KCl) (b) 

<2 µm 

2–50 µm 

> 50 µm 

Ap 
Ap 
Bw 
Bw 
2C 
2C 

Loam 
0–30 
Loam 
30–40 
Silt loam 
40–60 
Silt loam 
60–80 
80–100 
Sand 
100–170  Sand 

7.0 
7.0 
6.3 
6.3 
6.4 
6.4 

6.4 
6.4 
5.6 
5.6 
5.7 
5.7 

15 
15 
7 
7 
0 
0 

45 
45 
53 
53 
0 
0 

40 
40 
40 
40 
100 
100 

OM (%)  Oc (%)  Dry 
bulk 
density 
(g/cm3) 
1.3 
1.3 
1.35 
1.35 
1.45 
1.45 

1.26 
1.26 
0.47 
0.47 
0 
0 

2.17 
2.17 
0.80 
0.80 
0 
0 

Depth 
factor  
(–) 

1.0 
0.5 
0.5 
0.3 
0.3 
0.0 

(a):  Measured at a soil solution ratio of 1:2.5. 
(b):  These values are estimated from the measured water values according to Boesten et al. (2012). 
The depth factor indicates the relative transformation rate in the soil layer. 
The depth of the groundwater is 1.5 m (range 1.3–0.7 m). 

Table A4:   Soil hydraulic properties of the Italian greenhouse leaching scenario (after FOCUS 2009) 

Depth 
(cm) 

θs 
(m3/m3) 

θr 
(m3/m3) 

α 
(m–1) 

n (–) 

m (–) 

Water content 

10 kPa 
(m3/m3) 

1 600 kPa 
(m3/m3) 

Ksat 

(m/s 

 10–6) 

λ (–) 

AW (a) 
(mm) 

0–30 
30–40 
40–60 
60–80 
80–100 
100–170 

0.4622 
0.4622 
0.4543 
0.4543 
0.31 
0.31 

0.0100 
0.0100 
0.0100 
0.0100 
0.0150 
0.0150 

3.13 
3.13 
2.31 
2.31 
2.812 
2.812 

1.238 
1.238 
1.3531 
1.3531 
1.6060 
1.6060 

0.1993 
0.1993 
0.261 
0.261 
0.3773 
0.3773 

0.341 
0.341 
0.317 
0.317 
0.163 
0.163 

0.113 
0.113 
0.065 
0.065 
0.022 
0.022 

4.269 
4.269 
6.138 
6.138 
28.330 
28.330 

–2.037 
–2.037 
0.109 
0.109 
0.500 
0.500 

68.4 
22.8 
50.4 
50.4 
28.2 

(a):  Plant available water in the soil layer. 
Plant available water in top metre is 220.2 mm. 

EFSA Journal 2014;12(3):3615 

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Emission routes of PPPs from greenhouses and covered crops 

Figure A1:  Average  daily  temperatures  for  2011  for  Pistoia  (Italy).  T.out,  temperature  outside 
greenhouse; T.GH temperature inside greenhouse  

Figure A2:  Daily  global  radiation  for  2011  for  Pistoia  (Italy).  R.out,  radiation  outside  greenhouse; 
R.GH, radiation inside greenhouse. 

EFSA Journal 2014;12(3):3615 

29 

051015202530350100200300temperature (°C)day in yearT.outT.GH0510152025300100200300radiation (MJ/m2)day in yearR.outR.GH 
 
 
 
Emission routes of PPPs from greenhouses and covered crops 

Figure A3:  Evapotranspiration (line) and water irrigation (symbols) for a covered soil-bound Italian 
greenhouse tomato crop. Irrigation takes place after the total water deficit has exceeded the value of 20 
mm (management decision). 

Table A5:  Monthly average weather data of the Italian tomato greenhouse scenario 

Month 

Average 
radiation 
(MJ/m2) 

4 
5 
6 
7 
8 
9 

7.8 
10.4 
9.6 
7.8 
7.6 
7.8 

(a):   Evapotranspiration. 

Average 
temperature (°C) 

Average 
ET (a) (mm) 

Irrigation 
sum (mm) 

Drainage sum 
(mm) 

18.8 
20.8 
23.7 
27.9 
24.9 
24.6 

1.46 
3.70 
4.82 
5.4 
4.13 
4.18 

25 
128 
184 
184 
154 
53 

3.8 
19.6 
28.1 
28.1 
23.5 
8.1 

EFSA Journal 2014;12(3):3615 

30 

0.001.002.003.004.005.006.007.008.009.0005101520253035020406080100120140160Evapotranspiration (mm)Irrigation (mm)Days after transplantation 
 
Emission routes of PPPs from greenhouses and covered crops 

Appendix B.   Example  drainage  scenario  concerning  a  soil-bound  chrysanthemum  crop  in  a 
high-tech greenhouse in the Netherlands 

This appendix gives an example scenario for drainage of substances to surface water. For more details, 
see Wipfler et al. (2014 in prep.). The scenario may  be considered representative for the purpose of 
risk assessment of plant protection products for the Netherlands. This was checked within the limits of 
data availability. The representativeness for soil-bound greenhouse cultivations in the rest of Europe is 
unknown. In order to establish a representative scenario, a proper selection has to be performed (EFSA 
2012a, b). 

The following sections describe necessary parameters to construct a similar drainage scenario for soil-
bound  crops  in  greenhouses.  Data  in  the  tables  and  figures  pertain  to  the  example.  When  using  the 
PEARL model, the preferential flow option has to be switched on. 

The crop for this scenario is chrysanthemum,  until now almost always a soil-bound cultivation. In a 
greenhouse,  chrysanthemum  is  grown  more  or  less  continuously,  i.e.  beds  of  chrysanthemum  of 
different age are situated next to each other. On the same spot within the greenhouse, approximately 
five crops can be grown in one year. In such a greenhouse, crop protection (application of fungicides 
and/or  insecticides)  will  be  on  plants  of  different  age  as,  in  general,  a  full  compartment  of  a 
greenhouse has to be treated. This is reflected in assuming average plant characteristics all year round. 
Table B1 and Table B2 give the crop parameters.  

Table B1:  Crop parameters of the example Dutch chrysanthemum greenhouse scenario 

Crop 

Growth stage 

Emergence
(dd/mm) 

Harvest 
Planting 
(dd/mm) 
(dd/mm) 
Not  relevant  in  chosen  parameterisation,  averaged 
over year 

Senescence 
(dd/mm) 

Chrysanthemum 

(a):   Not relevant. 

Max LAI 

(m2/m2) 

(dd/mm) 

Root 
depth 
(m) 

12.0 

NR (a) 

0.3 

Table B2:  Crop Kc-factors of the Dutch chrysanthemum greenhouse scenario 

Crop 

Kc factor as a function of cropping periods (expressed in dd/mm-dd/mm) 

Harvest to 
emergence 
Period Kc 

Emergence to 
maximum LAI 
Period Kc 

Maximum LAI to 
senescence 
Period Kc 

Senescence to 
harvest 
Period Kc 

Chrysanthemum  1.00 

1.00 

1.00 

1.00 

Table  B3  and Table  B4  give  the  soil  parameters.  From  the  given  parameters, it  is  clear that  the  top 
25 cm of the soil profile differs substantially from the deeper layers. The deeper layers represent the 
original soil at the site, while the top layer is changed/replaced such that it is optimal for the growth 
and the handling of the crop. Soil management practices are such that these conditions are maintained 
over prolonged periods. 

EFSA Journal 2014;12(3):3615 

31 

 
 
 
Emission routes of PPPs from greenhouses and covered crops 

Table B3:  Soil parameters of the example Dutch chrysanthemum greenhouse scenario 

Depth 
(cm) 

Classification 

pH 
(H2O) (a) 

pH 
(KCl) (a) 

Horizon 

Texture (%) 

< 2 µm 

2–50 
µm 

> 50 µm 

om 
(%) 

oc 
(%) 

Dry bulk 
density 
(g/cm3) 

Depth 
factor  
(–) 

Ap 

B 
B 
B 
C 

0–25 

Sandy 
loam 
Clay 
25–30 
30–60 
Clay 
60–100  Clay 
Clay 
100–
200 

clay 

–99 

–99 
–99 
–99 

–99 

–99 

–99 
–99 
–99 

–99 

22.5 

63.5 
63.5 
63.5 

63.5 

0 

0 
0 
0 

0 

77.5 

36.5 
36.5 
36.5 

36.5 

13.7 

7.95 

0.893 

1.5 
1.5 
1.5 

1.5 

0.87 
0.87 
0.87 

1.462 
1.462 
1.462 

0.87 

1.462 

1.0 

1.0 
0.5 
0.3 

0.0 

(a):   –99 indicates that the pH of the soil is not available (has not been defined). 
The depth of the groundwater table is 0.8 m (artificial drains). 

Table B4:  Soil hydraulic properties of the Dutch chrysanthemum greenhouse scenario 

Depth 
(cm) 

θs 
(m3/m3) 

θr(m3/m3) 

α(m–1) 

n(–) 

m(–) 

Water content 

kPa 

10 
(m3/m3) 

1 600  kPa 
(m3/m3) 

Ksat 
(m/s  10–6) 

λ (–) 

0–25 
25–30 
30–60 
60–100 
100–200 

0.53 
0.57 
0.57 
0.57 
0.57 

0.01 
0.0 
0.0 
0.0 
0.0 

2.42 
1.94 
1.94 
1.94 
1.94 

1.280 
1.089 
1.089 
1.089 
1.089 

0.219 
0.0817 
0.0817 
0.0817 
0.0817 

0.427 
0.53 
0.53 
0.53 
0.53 

0.2 
0.386 
0.386 
0.386 
0.386 

9.407 
0.529 
0.529 
0.529 
0.529 

–1.476 
–5.955 
–5.955 
–5.955 
–5.955 

Table  B5  gives  an  overview  of  climatic  conditions  in  the  greenhouse.  Daily  temperature  data  for  a 
typical year of this scenario are shown in  Figure B1. From this figure, it is clear that temperature is 
controlled by heating during winter time with the minimum temperature set at approximately 18.5 °C. 
The  full  meteofile,  a  PEARL  input  file  and  a  lower  boundary  file  for  this  scenario  are  given  in  the 
separate Appendix F. 

Table B5: 
(period 1980–2000) 

Monthly  average  weather  data  of  the  Dutch  chrysanthemum  greenhouse  scenario 

Month 

Temperature 
(°C) 

Rain (a) 
(mm/d) 

Evapotranspiration 
(mm/d) 

Radiation 
(kJ/m2) 

Wind speed (m/s) 

Humidity 
(kPa) 

January 

18.8 

February 

18.9 

March 

April 

May 

June 

July 

August 

20.1 

20.5 

25.0 

25.7 

30.2 

26.6 

September 

22.4 

1.6 

1.9 

2.6 

3.5 

4.2 

4.3 

3.7 

3.8 

2.8 

1.1 

1.4 

1.9 

2.5 

2.8 

2.8 

2.7 

2.5 

2.0 

8 200.5 

8 336.6 

12 234.8 

14 059.1 

20 001.9 

19 815.4 

23 452.0 

18 743.0 

17 372.0 

0.7 

0.8 

1.2 

1.6 

2.3 

2.8 

3.1 

3.2 

2.5 

2.1 

1.4 

1.4 

1.4 

1.3 

1.6 

1.6 

1.5 

1.8 

EFSA Journal 2014;12(3):3615 

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Emission routes of PPPs from greenhouses and covered crops 

Month 

Temperature 
(°C) 

Rain (a) 
(mm/d) 

Evapotranspiration 
(mm/d) 

Radiation 
(kJ/m2) 

Wind speed (m/s) 

Humidity 
(kPa) 

October 

19.6 

November 

18.8 

December 

18.7 

Year 

22.1 

1.9 

1.6 

1.5 

2.8 

1.5 

1.1 

1.0 

1.9 

11 430.5 

10 346.6 

8 937.1 

14 446.0 

2.0 

1.1 

1.0 

1.9 

1.8 

1.6 

1.4 

1.6 

(a):  Average irrigation flux, in the models treated as rain (precipitation). 

Figure B1:  A  typical  temperature  (°C)  sequence  during  a  year  for  the  greenhouse  chrysanthemum 
crop in the Netherlands 

EFSA Journal 2014;12(3):3615 

33 

0510152025303540050100150200250300350temperature (°C)Julian day 
 
 
 
Emission routes of PPPs from greenhouses and covered crops 

Appendix C.   Example of a soil-less rose scenario in a high-tech greenhouse in the Netherlands 

This appendix gives an example scenario for a soil-less grown rose crop with discharge of deteriorated 
recirculation  water  to  a  ditch.  For  more  details,  see  Van  der  Linden  et  al.  (2014).  The 
representativeness of the scenario for the purposes of risk assessment of substances reaching surface 
water has been established for the Netherlands, for  soil-less grown crops with low sodium tolerance 
(< 4.5 mmol/L) and high transpiration (> 600 mm/year), within the limits of data availability. It is not 
known,  however,  how  data  rank  in  the  cumulative  distributions  in  the  rest  of  Europe.  In  order  to 
establish a representative scenario, a proper selection has to be performed (EFSA 2012a, b). 

The  following  sections  describe  necessary  parameters  to  construct  a  similar  scenario  for  soil-less 
cultivation in greenhouses. Data in the tables and figures pertain to the example. The scenario has been 
included in the software package GEM (see Van der Linden et al., 2013). 

The crop for this scenario is rose, as a cut flower, grown in a soil-less system. The crop is grown for 
several years. In such a growing system, crop protection (application of fungicides and/or insecticides) 
can be by treatment of the shoots (spraying, fogging or fumigation) or application to the recirculating 
nutrient solution (either to treat the roots or to apply systemic substances). The WATERSTREAMS 
model calculates water fluxes to and from the plants based on management set-points, the size of the 
rainwater  collection  basin  and  the  secondary  (and  tertiary)  water  sources  and  the  salt  (sodium) 
contents of these water sources (see Table C1). The drainage fraction indicates the excess water supply 
to  the  plants;  this  water  is  recirculated  in  the  greenhouse  system  until  it  is  discharged  because  of 
reduced water quality. Table C2 gives long-term average amounts of water balance, characteristic of 
the systems. In this particular case, it is not necessary to discharge recirculating water because of the 
abundance  of  water  of  good  quality  (the  secondary  water  source  is  reverse  osmosis  water).  In  this 
situation,  only  filter  rinsing  water  is  discharged  and  forms  a  potential  source  of  emission  of  PPP to 
surface water. The discharge, both water and substances (PPP and, if applicable, metabolites), can be 
used as input to the TOXSWA model. 

Detailed daily data on temperature and water streams in the soil-less greenhouse system are given in a 
separate appendix (Appendix G). 

Table C1:  Characteristics  and  management  settings  of  the  soil-less  growing  system  and  sodium 
contents of the water sources 

EFSA Journal 2014;12(3):3615 

34 

Characteristics of systemcropheatinghighmin temp 20 °Clight12000lux/m2rainwater basin1500m3/hadrain fraction0.5-numbertype[Na] (mmol/l)1rainwater0.12osmosis water0.13tapwater1.5rosewater sources 
 
 
 
 
Table C2:  Long-term average yearly amounts of water in the soil-less rose growing system 

Emission routes of PPPs from greenhouses and covered crops 

EFSA Journal 2014;12(3):3615 

35 

waterstreamm3/harain8671.6water supply to crop19188crop uptake9978drainwater9978condensation1626discharge0filter rinsing217leakage299basin water7463osmosis water1398tap water7 
 
 
Emission routes of PPPs from greenhouses and covered crops 

Appendix D.   Tiered approach surface water (SW) with respect to covered crops 

For surface water (SW) assessments (FOCUS Surface Water, 2001) for open field, a stepped approach 
is followed, with: 

  Step 1, maximum loading of the SW based on total applied amount of substance applied over 

the entire season/year 

  Step  2,  loading  as  is  Step  1,  but  accounting  for  disappearance  of  substance  between  two 

applications 

  Step 3, advanced modelling using FOCUS SW scenarios 

  Step 4, based on Step 3, but accounting for mitigation. 

When  the  guidance  for  covered  crops  states  ‗open  field  assessment  is  applicable‘,  the  open  field 
assessment is applicable without reservation, so all four steps could be applied dependent on available 
information. 

For covered crops, for which specific assessment are indicated (greenhouses, walk-in tunnels), specific 
(tailored) stepped approaches are suggested below. For the time being, steps equivalent to step 4 for 
open fields are not recommended as in general the necessary information is not available. 

Walk-in tunnels 

Only soil-bound cultivation, for soil-less cultivation see greenhouse soil-less. 

As suggested in Table 1 assessment is according to FOCUS D scenarios, i.e. run-off and erosion are 
not considered.  

At Step 1, inputs of spray drift and drainage are evaluated as a single loading to the water body and 
―worst-case‖  water  and  sediment  concentrations  are  calculated.  If  inadequate  safety  margins  are 
obtained  (toxicity  exposure  ratios  <  trigger  values),  the  registrant  proceeds  to  Step  2.  At  Step  2, 
loadings are refined as a series of individual applications, resulting in drift to the water body, followed 
by a drainage event occurring four days after the last application. Again, if inadequate safety margins 
are  obtained  (toxicity  exposure  ratios  <  trigger  values),  the  registrant  proceeds  to  Step  3.  Step  3 
requires the use of the deterministic models capable of calculating drainage, accounting for potential 
macropore flow (now MACRO) and fate and behaviour in surface water bodies (now TOXSWA). 

Greenhouses (soil bound) 

See walk-in tunnel. 

Greenhouses (soil-less) 

Two  types  of  application  are  to  be  distinguished:  drip  irrigation  (DI)  (application  with  nutrient 
solution) and spraying/fogging. 

Drip irrigation (DI) 

(It is assumed that emission to surface water is due to discharge only; other potential routes may be 
considered negligible.) 

EFSA Journal 2014;12(3):3615 

36 

 
 
Emission routes of PPPs from greenhouses and covered crops 

In Step 1, it is assumed that the soil-less system is operated as an open-loop system, i.e. the nutrient 
solution is not recirculated and the substance is not taken up by the crop. It is assumed that the amount 
of substance applied to the crop on one day (amount of a single application) flows out of the system 
with the drainage water. The worst-case assumption here is that two-thirds of the water supply is taken 
up by the crop and one-third is drained and that the drainage water upon discharge replaces the water 
in the surface water body. The concentration would then become equal to dose/drainage volume. 

Example rose in average year in the Netherlands 
The yearly average water supply to the crop is 18 m3/day (max = 45 m3/day). The 
yearly  average  amount  of  drainage  (=  excess  water  supply)  is  5  m3/day  (max  = 
11 m3/day).  So,  a  dose  of  1 kg  (applied  on  one  day)  would  result  in  0.2 kg/m3 
(200 mg/L).  for  comparison:  5 %  drift  in  open  field  would  result  in  17 µg/L  (a 
factor of 10 000 lower). 

In Step 2, plant uptake is taken into account. Some of the applied amount is taken up by the crop. As, 
in general, passive plant uptake is assumed and the TSCF (transpiration stream concentration factor) is 
< 1 (dependent on substance properties), there is a relative enrichment in the drainage water (i.e. the 
uptake of substance is relatively lower than the uptake of water. 

Example rose in average year in the Netherlands 
The yearly average water supply to the crop is 18 m3/day (max = 45 m3/day). The yearly 
average amount of drainage (= excess water supply) is 5 m3/day (max = 11 m3/day). So, if 
1 kg is applied, a TSCF of 0.5 would lead to an uptake of 360  g and a concentration in the 
surface water of 128 mg/L (a TSCF of 1 would result in 56 mg/L).  

Steps 1 and 2 for DI are probably only theoretical because criteria will not be met unless the substance 
has  very  low  toxicity.  It  is  not  necessary  to  account  for  volatilisation  and  subsequent  deposition  in 
surface water in these steps, because this process would contribute negligibly. 

Step 3 is the GEM approach. 

Spraying 

The substance reaches the water of the system when condensation water is collected via condensation 
water  and  this  water  is  used  as  a  preferential  water  source  (as  compulsory  in  the  Netherlands). 
(Substance may also reach the recirculating water when the amount of spray solution is so high that 
stem  flow  occurs.  This  is  not  considered  according  to  GAP.)  The  worst  case  is  when  condensation 
water  is  not  collected  and  drips  into  the  surface  water  body.  A  first  step  may  account  for  the  total 
dosage  over  a  season  assumed  to  be  applied  in  one  time.  A  second  step  may  look  into  the  separate 
applications. 

EFSA Journal 2014;12(3):3615 

37 

 
  
 
APPENDIX E. Greenhouse leaching scenario; climate input files 

Emission routes of PPPs from greenhouses and covered crops 

The Appendix is available as zip file at: http://www.efsa.europa.eu/en/efsajournal/pub/3615.pdf   

EFSA Journal 2014;12(3):3615 

38 

 
 
 
APPENDIX F.   Greenhouse drainage scenario; climate input files (PEARL)  

Emission routes of PPPs from greenhouses and covered crops 

The Appendix is available as zip file at: http://www.efsa.europa.eu/en/efsajournal/pub/3615.pdf   

EFSA Journal 2014;12(3):3615 

39 

 
 
 
 
Emission routes of PPPs from greenhouses and covered crops 

APPENDIX G. Greenhouse surface water scenario; input files for temperature and water 
streams 

The Appendix is available as zip file at: http://www.efsa.europa.eu/en/efsajournal/pub/3615.pdf   

EFSA Journal 2014;12(3):3615 

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Emission routes of PPPs from greenhouses and covered crops 

GLOSSARY AND ABBREVIATIONS 

closed building 

In  this  guidance  closed  building  means  Warehouses;  defined  areas  for  post 
harvest treatment with PPPs 

drift 

DI 

EC  

EEC  

EFSA  

GAP 

GEM 

small droplets that settle readily on surfaces (e.g. soil and surface water) 

drip irrigation 

European Community  

European Economic Community  

European Food Safety Authority  

Good Agricultural Practice 

Greenhouse  Emission  Model  which  will  be  made  available  at 
www.pesticidemodels.eu 

GH 

greenhouse 

emission  

technical term signifying the transfer of a substance over a boundary  

ERA  

EU  

Environmental Risk Assessment  

European Union  

FOCUS  

FOrum for the Co-ordination of pesticide fate models and their USe  

GIS 

GW 

irrigation 

LAI 

MACRO 

mBCA 

Geographical Information System 

groundwater 

The  application  of  water  to  soil  to  ensure  that  crop  receives  its  full  water 
requirements,  which  is  ‗the  depth  of  water  needed  to  meet  the  water  loss 
through  evapotranspiration  of  a  crop,  being  disease-free,  growing  in  large 
fields under non restricting soil conditions, including soil water and fertility, 
the  given  growing 
and  achieving 
Papers, 
Drainage 
(FAO, 
environment‘. 
ftp://ftp.fao.org/agl/aglw/docs/irrigman4.pdf ). 

full  production  potential  under 
Irrigation 

and 

Leaf area index (LAI) is a dimensionless quantity largely used to characterise 
crop canopy.  It  is  defined as  the  total leaf  area (one sided)  per  unit  ground 
area. 

Leaching  model,  specifically  developed  for  addressing  macroporous  water 
flow in soils 

Microbial biological control agent. the main groups of mBCAs are bacteria, 
fungi, viruses, protozoa and microsporidia (OECD 6) 

metabolite 

See transformation product 

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Emission routes of PPPs from greenhouses and covered crops 

micro-organism 

Any  microbiological  entity,  including  lower  fungi  and  viruses,  cellular  or 
non-cellular,  capable  of  replication  or  of  transferring  genetic  material. 
Regulation 1107/2009 

MS 

OC 

OM 

Member State of the European community 

organic carbon 

organic matter 

open structure 

Shelter with permeable cover (e.g. shade house and net house) 

Over-irrigation 

Application of water in excess of crop evapotranspiration due to the need of 
leaching  out  salts  from  the  root  zone  and/or  as  a  result  of  low  irrigation 
efficiency or of poor irrigation management. 

PEARL 

permanent 

Pesticide Emission At Regional and Local Scale. Model for calculating fate 
and behaviour of substances in soil 

The  crop  is  covered  during  the  whole  growing  cycle;  in  case  of  plastic 
materials, the cover is replaced every one or more years 

PEC  

Predicted Environmental Concentration  

PECair  

PEC in air  

PECsoil  

PEC in soil  

PECsw  

PEC in surface water 

PELMO 

PPP  

PPR  

PEsticide  Leaching  MOdel.  Model  for  calculating  fate  and  behaviour  of 
substances in the soil 

plant protection product  

Panel on Plant Protection Products and their Residues  

precipitation 

The quantity of rainwater deposited on the soil 

protection 

PRZM 

receptor  

The word ―protection‖ is often used to refer to physical barriers (i.e. plastic, 
glass or netting) or to refer to chemical/biological products that are applied to 
the crop (e.g. pesticides or plant growth regulators). Since this term could be 
ambiguous,  we  have  chosen  to  use  the  term  ―PPPs‟   to  refer  to  products 
(Plant  Protection  Products).  When  the  word  ―protection‖  or  ―protected‖ 
appears, it refers to the physical barriers. 

Pesticide  Root  Zone  Model.  Model  for  calculating  fate  and  behaviour  of 
substances in the unsaturated zone of the soil 

For the purpose of this opinion, a receptor is an environmental compartment 
receiving emissions, such as surface water, air, soil or groundwater 

spray boom 

A  device  consisting  of  a  pipe  with  nozzles  for  distributing  spray  from  a 
container. It is generally mounted on to the rear of a tractor or quad 

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solids  

For the purpose of this opinion, solids are defined as solid materials such as 
plastic covers, plant residues, soil and substrate that can be removed from the 
protected structure. 

substrate 

Any material, not in connection with sub-soil, used for growing plants on 

SWAP 

TOXSWA 

Soil Water Atmosphere Plant model. Model for calculating water and heath 
transport in soil. 

TOXic  substances  in  Surface  WAters.  Model  for  calculating  fate  and 
behaviour of substances in water courses 

temporary 
structure 

A structure used to cover a crop during part of the growing cycle (generally, 
in the first growth stage) or removed soon after the end of harvest season 

transformation 
product  

For the purpose of this Guidance Document, a transformation product means 
any  metabolite  or  a  degradation  product  of  an  active  substance,  safener  or 
synergist formed either in organisms or in the environment in agreement with 
Regulation (EC) 1107/2009 

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