OUT UNDER MONTREAL PROTOCOL -A CONCRETE OPPORTUNITY TO BAN A HAZARDOUS
It is well established that some widely
used man-made chemicals are destroying the stratospheric ozone layer,
which shields the earth from ultraviolet radiation. A strong international
consensus on protection of the ozone layer developed and was given
form in the Montreal Protocol on Substances that Deplete the Ozone
Layer that came into force in January 1989. Methyl bromide has been
identified as one of the chemicals depleting the ozone layer and
its phase out was considered a very important step, although pre-shipment
and quarantine uses (about 22% of global methyl bromide use) are
exempt from the controls of the Protocol. In non Article 5(1) countries,
which includes EU, the ban is in effect from 1 January 2005 onwards
with quotas allocated for “critical use exemptions”.
In the European Union the legal framework is set by Regulation EC
2037/2000, which is slightly stricter.
But despite the stricter regulation in terms of phasing out and
ceasing the production, the EU fails in getting rid of methyl bromide
as it should. Allocation for critical use exemptions in EU countries
was 4,032t in 2005 despite the existence of feasible alternatives.
This represents roughly 27% of the consumption registered in 1993.
This quota allocation for the EU countries represents 27.8% of the
total allocation to non Article 5(1) countries in 2005. In addition,
a 59.0% quota was allocated to the USA, 7.2% was allocated to Israel
and 4.8% was allocated to Japan (1). Within the EU, eight countries
have requested critical usage: Belgium, Spain, France, Greece, Italy,
Poland, Portugal and the UK. The other countries do not use methyl
bromide as soil fumigant but only Denmark, Finland and Sweden seem
to have taken their commitment more seriously, with either no quarantine
and pre-shipment uses or critical exemption uses.
Methyl bromide not only depletes the ozone layer; it’s also
a hazardous pesticide classified as a Bad Actor by PAN North America
due to its acute toxicity, moderate aquatic toxicity and for being
a developmental or reproductive toxin (2). Methyl bromide is toxic
to the central and peripheral nervous systems and exposure is known
to cause skin, kidney, respiratory, liver and neurological damage
resulting in severe or permanent health effects (2), (3), (4), (5).
Acute exposure can also cause death (6), (7) and serious effects
such as pulmonary edema, congestion, and haemorrhage (8). The risks
are not confined to workers and applicators but also include other
workers not actually involved in the fumigation and the general
public in the vicinity (9), (10), (11).
Table 1: Phase out of methyl bromide
under EU Regulation EC 2037/2000 and Montreal Protocol
|EU Regulation EC 2037/2000
||Non Article 5(1) countries
||Article 5(1) countries
|. 25% reduction by 1998
||. 25% reduction by 1999
||. Freeze by 2002 at average 1995-1998 level
|. 60% reduction by 2001 and freeze quarantine and pre-shipment
||. 50% reduction by 2001
||. Review of reduction schedule in 2003
|. 75% reduction by 2003
||. 70% reduction by 2003
||. 20% reduction by 2005
|. End of production by 31/12/2004
|. Phase out by 2005 except for critical use exemptions
||. Phase out by 2005 except for critical use exemptions
||. Phase out by 2015 except for critical use exemptions
Source: UNEP (1998) (12)
Article 5(1) countries are, according to the Protocol "Any
Party that is a developing country and whose annual calculated level
of consumption of the controlled substances in Annex A is less than
0.3 kilograms per capita..."
USES OF METHYL BROMIDE
About 71,500t of methyl bromide are used annually worldwide and
around 97% is used as a fumigant for pest control, mostly in developing
countries (75%) (12). Methyl bromide is used as an insecticide,
acaricide, rodenticide and soil sterilant. Its properties were first
described in 1932 and were introduced by Dow AgroScience, who no
longer manufacture or market it. It is extremely phytotoxic and
is used as a multi purpose fumigant used for pest control in mills,
warehouses, grain elevators, etc.; in stored products; soil fumigation
for control of insects, nematodes, soil-borne diseases, and weed
seeds; and glasshouse and mushroom-house fumigation (13).
Soil fumigation is the single largest use category, accounting for
about 76% of global use. Most is used for the fumigation of horticultural
crops including tomatoes, strawberries, melons, cucumbers, peppers,
tobacco and cut flowers (14). In the fumigation process methyl bromide
is applied either to the soil surface or by mechanized injection.
For surface applications, the area to be treated is covered with
plastic sheeting and the gas is released into the space between
the soil surface and the sheet.
Of the quantity allocated to EU under the critical use exemption
in 2005, Italy receives 2,133t, Spain 1,059t, France 431t, Greece
200t, UK 74t, Portugal 50t, Belgium 45t and Poland 40t. The use
in crops is divided up into: 1,544t in strawberry production, 452t
for cut flowers, 394tfor peppers, 230t for cucurbits, 227t for aubergines
and 58t for other crops (1).
Durable commodities and structures
Some economically important commodities including dried fruit and
nuts, cereal grains and flour and timber use methyl bromide as a
principal means of pest control. Pests that infest durable commodities
often establish in the buildings or structures where the food is
stored or processed. Wood destroying insects can also infect the
wooden parts of the building. The UN Methyl Bromide Technical Options
Committee (MBTOC) estimated that the treatment of durables is responsible
for 13% of methyl bromide used worldwide – 19% in developing
countries – and the treatment of structures and vehicles is
responsible for 3% (14).
Methyl bromide is the most widely used treatment for disinfestation
of perishable commodities. About 9% of global methyl bromide consumption
is used for disinfestation of perishable commodities, with about
half used for disinfestation of fruit for quarantine purposes (14).
CHEMICAL ALTERNATIVES IN THE EUROPEAN UNION
Although the EU has been making progress in phasing out methyl bromide,
the chemical alternatives in consideration are mostly hazardous
for health and the environment and should be avoided. They are currently
going through review under the Pesticides Authorisation Directive
(Directive 91/414/CEE) and many of them will see a final decision
about their authorisation for the EU market during 2005.
On the one hand the Montreal Protocol contributed to phase out the
use of a hazardous fumigant; on the other hand it’s not clear
whether Europe will take this opportunity to replace it for better
alternatives for health, environment and farmers’ economies.
We might be committing a new error, one that will take many years
to solve and lead to considerable costs for health and the environment.
Due to the serious hazards and environmental fate associated with
the chemical alternatives, all efforts should be made to encourage
non-chemical alternatives to methyl bromide.
Table 2: Chemical alternatives classified by hazard, stage
in the Directive 91/414 review and possible date of decision
||Possible date of decision
|1,3 - D
||AT, C, GWC
|Metam (sodium or potassium)
||AT, C, DFT, AAT
||New active substance
||AT, potential GWC
||AT, CI, moderate AAT
||AT, CI, AAT
||AT, CI, potential GWC
||Moderate AT, possible C, CI, suspected ED, AAT
||Included in Annex I 14/01/2003
||Slight AT, C
Source: PANNA database (2), Tomlin (2003) (13), Proceedings of
5th International Conference (15)
Notes: AT – Acute toxicity; C – Carcinogen; DRT –
Developmental or reproductive toxin; AAT – Acute aquatic toxicity;
CI – Cholinesterase inhibitor; ED – Endocrine disruptor;
GWC – Ground Water Contaminant
NON-CHEMICAL ALTERNATIVES TO METHYL BROMIDE
MBTOC, which is made up of experts from all over the world, and
which oversees the search for alternatives, defined alternatives
as “those non-chemical or chemical treatments and/or procedures
that are technically feasible for controlling pests, thus avoiding
or replacing the use of methyl bromide”. “Existing”
alternatives are those in present use in some regions; “potential”
alternatives are those in the process of investigation and development.
Although in some regions a high number of dispersed small users
can make the transition difficult, experience in Multilateral Fund
projects (projects funded under the Montreal Protocol) shows that
very large numbers of methyl bromide users can be trained and prepared
for alternatives within a relatively short period of time and that
adoption of alternatives can occur rapidly (16).
Alternatives can be identified for virtually all uses of methyl
bromide and many of them are in use in different countries around
the world. However, there is no single substance that can replace
methyl bromide in all its applications. Many of the alternatives
consist of a combination of practices and techniques to achieve
1. Alternative soil treatments
In most cases an Integrated Pest Management approach is necessary
for soil-borne control of pest to be effective, safe and environmentally
benign. A number of non-chemicals are in use and potential alternatives
are under investigation.
Crop rotation and cover crops: are used effectively in
many parts of the world as part of a successful IPM approach. For
example, oilseed rape produces isothiocyanate and related mustard
oils, which kill fungi and nematodes and is used in many crop rotation
schemes (12). A number of crops including castor (Ricinus communis),
oat (Avena sativa), sorghum (Sorghum bicolour), crotalaria (Crotalaria
spectabilis), sunn hemp (C. juncea) and various grasses are known
to suppress root-knot nematodes. Although less effective than solarisation
or soil fumigation, the efficacy of cover crops might be improved
by combining with other methods such as the use of nematode-resistant
Fertilization and plant nutrition: if properly managed can
reduce significantly pests and diseases. For example, pod rot in
peanut can be reduced by enhanced calcium nutrition by application
of lime to the soil (12).
Plant growth substances/organic amendments: composted soft
wood and hard-wood bark reduce the incidence of soil pathogens such
as Pythium ultimum, a fungus that causes damping-off disease under
green-house and field conditions. Soil amendments with composted
olive and fresh grape pomace caused a significant reduction of root-knot
nematodes in melon in Italy. Limitations however include lack of
large-scale manufacturers, inconsistency in product characteristics,
high transportation costs, etc. (17). Rock wool, tuff stone, clay
granules, waste grain hulls, forestry and industry waste can provide
clean soil substitutes allowing good nutrition and enhancement of
natural predators (12). Strawberry growers in Scotland are successfully
using a mixture of 40% white peat and 60% black peat and lately
adding coconut fibre, completely free from pests so that the use
of fumigants is not necessary. The farmer is also able to manage
more efficiently water and nutrient inputs, maximizing crop yields
and quality (18). The downside, in this case, is the likely destruction
of valuable habitats caused by the extraction of the materials.
Resistant varieties and grafting: plant breeding and grafting
can produce crop species resistant to nematodes, pathogenic fungi
and specific pest problems. For example, presently, 100% of the
watermelon crop in Spain is from grafted plants, a technique that
eliminated the use of methyl bromide. It is used with good results
in the control of root-knot nematodes and fungal pathogens in peppers,
fruit trees and citrus (17).
The fungus Pochonia chlamydosporia has been investigated as a potential
biological control agent for use in integrated pest management strategies
for control of root-knot nematodes in organic production. The fungus
significantly reduced nematode infestations in soil following a
tomato crop, in a strategy that combined the use of the fungus with
crop rotation (17). The introduction of rhizobacteria (i.e. bacteria
that develop in and around plant roots) that are antagonistic to
plant pathogens and develop along with the seedling roots to form
a biological shield around the roots, can help protect the plant
in the early growth stages (12).
Steam: is the introduction of vapour at 100° C into
the soil where it kills soilborne pests with the latent heat released
when it condenses into water. Under appropriate conditions it can
be as effective as methyl bromide. In the Netherlands where methyl
bromide was banned as early as 1992, this technique is successfully
used as an alternative (12). Steaming is suitable as an alternative
in protected cropping systems and small-scale, open-field production,
e.g. bulbs, strawberries, cut flowers or ornamental plants (17).
Solarisation: consists of trapping sun heat under clear
plastic sheeting to elevate the temperature of moist soil to temperatures
lethal to soil-borne pests including pathogens, weeds and insects.
It is most successful in dry climates with low number of cloudy
days and intense solar heat. It is used by farmers in Jordan, Israel,
Italy, Spain and other Mediterranean countries (12). It is more
effective in combination with other techniques, especially when
dealing with other mobile organisms such as nematodes that will
move deeper into the soil with solarisation. Solarisation is used
successfully in Israel to produce peppers and eggplant in winter
to control nematodes, weeds, fungi, bacteria and parasitic plants,
providing the same yields and costing substantially less than methyl
Biofumigation: is the amendment of soil with organic matter
that releases gases which kill or control pathogenic micro-organisms.
This technique, combined with solarisation, has provided good results
in the production of bananas, tomatoes, grapes, melons, peppers
and other vegetables (17). In Macedonia, a combination of biofumigation
and solarisation for tomatoes and cucumbers in greenhouses provided
similar yields to methyl bromide at lower costs. The technique consists
of mixing moist soil with organic matter (e.g. manure) and covering
it with a polyethylene sheet (19). The incorporation into the soil
of residues of some brassicas and Compositae family plants gives
excellent results as these release volatile chemicals such as methyl
isothiocyanate and phenethyl isothyocianate which have herbicidal,
fungicidal and/or nematocidal properties (12).
Integrated Pest Management (IPM)
IPM is based on combination of strategies to prevent and manage
pest problems in an environmentally sound and cost-effective way.
Success of IPM is reported all around the world (17) and is should
be a cross-compliance condition for support to farmers in the framework
of the European Common Agricultural Policy. For example in France,
farmers are increasingly using IPM to reduce and prevent the effects
of pests and diseases in melon, tomato, strawberries and cucumber
that includes the use of resistant tomato varieties suitable for
grafting or soil-free culture for strawberries (17). IPM is successfully
used in open field strawberry production in Poland, at lower costs
when compared to methyl bromide and providing higher average yields.
Key IPM elements include: crop rotation and planting of appropriate
crops before strawberries; application of animal manure and sometimes
green manure; use of healthy plantlets free from pests and diseases
Alternatives that avoid the need for soil desinfestation
Soil-free culture: is a method in which plant growth substrates
provide a medium that allows water and nutrients to be absorbed
by the roots. Most soil-free culture occurs in covered or protected
agriculture and substrates include artificial and natural materials
such as rock wool, tuff, clay granules, solid foams, glass wool,
peat, coconut plant materials, volcanic gravel or pine bark. It
is used for crops such as tomato, strawberries, cut flowers, melons,
cucurbits or tobacco seedlings (17). Constraints include availability,
water pollution from systems that do not recycle the nutrients and
the vulnerability to pathogen attacks.
2. Alternative treatment for durable commodities and structures
Physical control methods
Heat treatment: grain or other commodities are heated to
temperatures of 60-70ºC and then cooled rapidly. At around
65ºC disinfestations from stored-products insects can be achieved
in less than 1 minute (17).
Cold treatment: cooling is used to prevent damage and multiplication
and reinvasion of pests. Cold treatments are now used as part of
Integrated Pest Management for stored products such as grain, oilseeds
and seeds (17).
Controlled and modified atmospheres: based on a high content of
carbon dioxide or nitrogen offers alternatives to fumigation for
control of arthropod insects and vertebrate pest control. Nitrogen
based controlled atmospheres can also be used to control rancidity
as well as pests in some nuts (17). An integrated control using
low oxygen disinfestations and protective methods using pathogens,
low oxygen and low temperatures proved effective in walnuts, almonds
and raisins (17). In Germany, a combined atmosphere of nitrogen
and carbon dioxide is used for the protection of wood and wooden
items successfully (14).
Integrated Pest Management (IPM)
An integrated pest management programme must begin with the identification
of existing and potential threats, the cause of their presence,
their vulnerability and consideration of chemical and non-chemical
methods. A major component of the IPM is system is sanitation or
“hygiene” which generally involves measures to remove
pests and deny them access to the facilities. These measures include
cleaning and removal of food debris to prevent pest multiplying
and redesigning and modifying buildings and machinery to eliminate
harbourage for pests. The IPM approach has been introduced successfully
in food and flour processing facilities in many countries (17).
In Canada, for example, the Canadian Methyl Bromide Industry Government
Working Group has prepared an IPM strategy for use in food processing
Insect pathogens: such as bacteria, viruses, protozoa,
nematodes and fungi can be used to control pests. Commercial formulations
of Bacillus thuringiensis provide control of almond moth and Indian
meal moth when applied to grain in a suspension or in dust. Bacillus
thuringiensis and other pathogens can also form part of an IPM approach
Pheromones: are chemicals produced by one member of a
species that are transmitted to influence the behaviour and physiology
of another member of the same species. Pheromones can be used as
trap baits or employed in direct control via mass trapping, pathogen
dissemination and disrupting mating. Synthetic versions of pheromones
are commercially available for many of the most important pest species
(16). The use of pheromone traps for Indian meal moth and warehouse
beetle is reported as part of an IPM approach for the protection
of food processing facilities in USA. The traps are used either
for monitoring purposes or for mass trapping (18).
Botanicals are components derived from plants. Nowadays they are
likely to form part of an IPM approach or for small on-farm use
in developing countries. The only botanical in use in developed
countries for protection of durable goods is pyrethrum extract,
which has toxic and repellent properties. Others, such as azadirachtrin
(active ingredient from neem tree) are registered for plant protection
and under continuous investigation for the protection of durable
goods (12, 17).
3. Alternative treatment for perishable commodities
A constraint on the development of alternatives for treatment of
commodities before the export is that they need to be suited to
the combination of pests and commodities, which can make the transfer
of technologies between countries difficult (12). Treatments for
controlling quarantine pests have to be approved by the authorities
of importing countries and this usually requires scientific data
to demonstrate that the treatment is virtually 100% effective. Historically,
this process for gaining approval has been very slow (14).
Cultural practices: such as harvesting when pests are not
active or planting/grafting resistant varieties can be used.
Certified pest-free zones and pest-free periods: is also
accepted in some countries as an adequate treatment. Certification
of pest-free zones requires constant monitoring, reporting and enforcing
but is already in practice in a number of countries (12). For example:
melons from the Netherlands free from Mediterranean fruit fly exported
to Japan; orange, grapefruit, clementine and mango from Mexico exported
to USA (14).
Inspection and certification: is a way to avoid treatment.
Samples of the produce are inspected prior to the shipment and certified
based on finding no pests of quarantine importance. It is used,
for example in: cut flowers from the Netherlands exported to Japan;
apples from Chile and New Zealand exported to USA; green vegetables
exported to many countries (14).
Cold treatment: temperatures are typically reduced to between
-1 and + 2ºC. It is used for a number of fruits such as apples,
cherries, grapes, citrus and generally applied to a number of fruits
from tropical and subtropical countries (14). Cold treatment is
approved for use as quarantine treatment in at least 55 countries
that export perishable commodities mainly to USA and Japan, including
many European countries (17).
Heat treatment: hot water immersion, high temperature forced
air, and/or vapour heat are three heat treatment technologies that
can be used for post-harvest insect control for perishable commodities
such as fresh fruits, fresh vegetables, bulbs, and cut flowers.
Heat treatments for disinfestation of fruit have been used since
1929 in the USA when a vapour heat treatment against the Mediterranean
fruit fly was developed. However, interest in heat treatments waned
with the development of chemical fumigants, notably methyl bromide
(21). Heat treatment is a quarantine treatment approved, for example
in: mangoes exported to Japan; orchids, plants and cuttings exported
to USA; several vegetables exported to USA (14).
Controlled atmosphere: uses lack of oxygen to kill pests,
either raising carbon dioxide or nitrogen to replace a normal atmosphere
for a period of several weeks or even months. Due to the long period
of treatment, this technique is suitable for produce into long storage
periods, such as apples or pears (17).
To overcome the possible economic consequences of withdrawing the
use of methyl bromide, the Montreal Protocol has created a technical
advisory committee to oversee the search for alternatives, the MBTOC
(Methyl Bromide Technical Options Committee). In Europe, substantial
efforts have been invested into finding and implementing alternatives.
PAN Europe questions why after such a long transition period, methyl
bromide is still used for certain “critical use exemptions”.
Chemical alternatives under review in the framework of pesticides
authorisation policy in Europe offer reasons for concern. Many of
these chemicals present more than two of the following hazards:
acute toxicity, carcinogen, developmental or reproductive toxin,
acute aquatic toxicity, cholinesterase inhibitor, endocrine disruptor
and/or ground water contaminant. An array of viable non-chemical
alternatives exists and have been tested, many of them with economic
advantages for farmers in comparison with methyl bromide. PAN Europe
demands that non-chemical alternatives should be promoted and implemented
as the best options to benefit health, environment and rural economies.
1. Bello A, Diez Rojo MA (2004).
“Essential” use of methyl bromide as a soil fumigant
and its alternatives: the case for the year 200. PAN Europe Network
Conference Proceedings, not yet published.
2. PANNA Pesticide database: http://www.pesticideinfo.org
3. Geyer HL, Schaumburg HH, Herskovitz S. (2005). Methyl bromide
intoxication causes reversible symmetric brainstem and cerebellar
MRI lesions. Neurology, April, 12; 64(7): 1279-1281.
4. Acuna MC, Diaz V, Tapia R, Cumsille MA (1997). Assessment of
neurotoxic effects of methyl bromide in exposed workers. Revista
Medica de Chile, January, 125(1): 36-42.
5. De Haro L, Gastaut JL, Jouglard J, Renacco E (1997). Central
and peripheral neurotoxic effects of chronic methyl bromide intoxication.
Journal of Toxicology. Clinical Toxicology, 35(1): 29-34.
6. Herzstein J, Cullen MR (1990). Methyl bromide intoxication in
four field-workers during removal of soil fumigation sheets. American
Journal of Industrial Medicine, 17(3): 321-326.
7. Squier MV, Thompson J, Rajgopalan B (1992). Case report: neuropathology
of methyl bromide intoxication. Neuropathology and Applied Neurobiology,
Dec, 18(6): 579-584.
8. Fuortes LJ (1992). A case of fatal methyl bromide poisoning.
Veterinary and Human Toxicology, 1992, Jun, 34(3): 240-241.
9. Yang RS, Witt KL, Alden CJ, Cockerham LG (1995). Toxicology of
methyl bromide. Reviews of Environmental Contamination and Toxicology,
10. De Vreede JA, den Boeft J, van Hemmen JJ (1998). Exposure to
methyl bromide during greenhouse fumigation on Crete, Greece. Archives
of Environmental Contamination and Toxicology, October, 35(3): 539-547.
11. Guillemin MP, Hillier RS, Bernhard CA (1990). Occupational and
environmental hygiene assessment of fumigations with methyl bromide.
Annals of Occupational Hygiene, December, 34(6): 591-607.
12. UNEP (1998). Methyl Bromide: getting ready for the phase out.
13. C.D.S. Tomlin Ed (2003). The Pesticide Manual, 13 Edition. BCPC.
14. UNEP (2001). Sourcebook of Technologies for Protecting the Ozone
Layer: Alternatives to Methyl Bromide.
15. EC (2004), Proceedings of the 5th International Conference on
Alternatives to Methyl Bromide, Lisbon, 27-30 September 2004, Available
16. UNEP (2004). Critical Use Nominations for Methyl Bromide. Final
Report. Report of the Technological and Economical Assessment Panel,
17. UNEP (2002). Report of the Methyl Bromide Technical Options
Committee; 2002. Available online http://www.unep.org/ozone/teap/Reports/MBTOC/index.asp
18. UNEP DTIE (2000). Case studies on alternatives to Methyl Bromide,
Volume I: Technologies with low environmental impact.
19. UNEP DTIE (2002). Case studies on alternatives to Methyl Bromide,
Volume II: Technologies with low environmental impact in countries
with economies in transition. Available online http://www.uneptie.org/ozonaction/library/mmcfiles/3970-e.pdf
20. Website of the Canadian Methyl Bromide Industry Government Working
21. EPA (1996). Methyl Bromide Alternatives 10 Case Studies Vol.
II, EPA 430-R-96-012, Available online: http://mbao.org/fortc2.html