Chemical Industry News No. 75 Summer-Autumn 2013
- Inversion layers and chemical sprayers
- Check what you're feeding to livestock
- Alan has left the building
- Controlling rabbits with aluminium phosphide tablets
- Reporting spray drift
- $2000 fine for exceeding maximum chemical residue levels in calves
- Dichlorovos grain protection products suspended
- Cross contamination: an industry-wide issue
- Spray notification counts
- The bane of our lives
- Store farm chemicals correctly
Inversion layers and chemical sprayers
Neil Harrison, Chemical Standards Officer
Have you ever seen smoke rise straight up out of a chimney and watched it suddenly move horizontally? If the answer is yes, then you were watching the smoke hit a layer of air called a 'surface temperature inversion layer'.
While there are different types of inversions, all are defined as a layer of air in which the air temperature increases with height from the earth's surface, which is the opposite of normal conditions.
An inversion can form when the overnight cooling effect of the earth's surface causes the air immediately adjacent to the ground to also cool. Subsequently, the air is cooler near the ground and then warms up as height increases.
Surface temperature inversions are of significant concern when it comes to spray drift risk. Fine droplets of pesticides can concentrate at relatively high levels under the inversion layer and stay suspended for many hours, not being influenced by gravity.
The Australian Pesticide and Veterinary Medicine Authority suggests the potential for inversions to occur and to adversely hold high concentrations of airborne pesticides near the surface should always be anticipated between sunset and up to an hour or two after sunrise; unless one or more of the following conditions occur:
- There is continuous overcast, low and heavy cloud.
- There is continuous rain.
- Wind speed remains above 11 km/h for the whole period between sunset and sunrise.
Be mindful that established inversions can sometimes still occur when winds are in excess of 11 km/h.
The occurrence of any of the three conditions does not wholly exclude surface inversion existence, but they do indicate conditions not normally conducive to the drift of high concentrations of airborne pesticides.
If you consider an inversion layer as a large scale air mass, the inversion can slowly follow the topography of the landscape down slope due to the cold air drainage effect.
This creates a risk that any suspended particles trapped within the inversion will be carried off-target and settle potentially kilometres away from the target area.
Check what you're feeding to livestock
Alex Perera, Chemical Standards Officer
Livestock producers are reminded to ensure any horticultural by-products being fed to their animals are fit for purpose and free from unacceptable chemical residues.
Horticultural by-products used as stock feeds can jeopardise valuable livestock markets if they are contaminated with chemicals not intended for livestock consumption.
By-product stock feeds may be in the form of failed crops or crop waste from harvesting and processing. Examples of commonly used novel by-product stock feeds include grape marc, grape seed meal, tomato pomace, vegetable leaves, almond hulls and citrus pulp.
Before feeding by-products to livestock, producers need to ensure:
- the chemicals applied to the crop allow treated produce to be used as stock feed
- any withholding periods or restraint statements have been complied with
- there are no unacceptable residues present in the by-product stock feed.
This will minimise the risk of unacceptable chemical residues being detected in livestock products, including meat, milk and eggs.
Some chemical product labels contain prohibitive statements which specify that by-products from treated crops should never be fed to livestock. Failure to comply with such warnings or withholding periods can result in unacceptable chemical residues being detected in livestock products and place markets at risk.
It is an offence in Victoria to sell agricultural produce and by-products if the withholding period has not expired, unless the seller notifies the buyer in writing.
Using vendor declarations when trading in by-products can help to minimise the risk of unacceptable chemical residues occurring in livestock products by advising buyers which chemicals have been applied to the stock feed.
For more information, or to download a vendor declaration, visit the Meat and Livestock Association website www.mla.com.au
Alan has left the building
On Friday 16 November, Alan Roberts retired from DPI after a career spanning 40 years.
Alan started his working life in the early '70s as a "Nasho". He then worked on a number of central Victorian mixed farms and the University of Melbourne School of Agriculture farm at Mt. Derrimut, where he gained his experience in using agricultural and veterinary chemicals.
In the late 1970's, Alan retrained as a TAFE teacher and quickly became involved in the development and implementation of the Farm Chemical Users Course, which went through various iterations as ChemCert, and now as AusChem in Victoria. Alan trained hundreds of central and northern Victorian farmers in chemical use during his 10 years at Bendigo TAFE.
In the late 1990's, Alan began working for DPI as a Regional Chemical Standards Officer. He then became a Senior Chemical Standards Officer and finally, the statewide Program Manager for Chemical Standards Field Services.
Alan commented that his time with DPI provided him with the opportunity to work with a fantastic team and to be involved in a range of industries, meeting and working with many highly professional people across agriculture and horticulture. Best of all, he was able to make a difference to chemical use, produce quality, and market access in Victoria.
We thank Alan for his valuable contributions during his time with DPI and wish him well in the future.
Controlling rabbits with aluminium phosphide tablets
Alan Roberts - Plant and Chemical Operations
Land owners and managers are legally required to control rabbits on their property under the Catchment and Land Protection Act 1994. Using aluminium phosphide tablets is one way to fumigate rabbit burrows for rabbit control.
Aluminium phosphide tablets are supplied in a solid, shelf stable form. When exposed to the humid environment inside a rabbit burrow, the tablets react with moisture in the air to liberate highly toxic phosphine gas. Each 3 gram tablet liberates 1 gram of phosphine gas when it reacts with the moisture in the air.
While the Directions for Use are easy to follow, there are a few issues users should be mindful of before using these products:
1. All metallic phosphide products including aluminium phosphide are Schedule 7 Dangerous Poisons, which makes them 'restricted use' chemicals in Victoria. The user must hold an Agricultural Chemical User Permit (ACUP), or be working under the direct and immediate supervision of an ACUP holder.
2. Not all aluminium phosphide products are approved for controlling rabbits. As these products are 'restricted use' chemicals, they must only be used according to their label directions. Only the following products have approval for use in controlling rabbits:
- Quickphos Fumigation Tablets
- Farmoz Pestex Fumigation Tablets
- Farmalinx Grainpro Fumigation Tablets
- Apparent Phosphine fumigation Tablets.
Aluminium phosphide products are classed as 'Dangerous Goods', and are generally Class 4.3, 6.1 or both. Diamonds on the reverse of the labels identify Dangerous Goods.
Class 4.3 products are "Dangerous When Wet" and Class 6 are "Toxic", and together this is a potentially hazardous combination.
If aluminium phosphide tablets get wet, under the right combination of conditions, a reaction called 'deflagration' may occur. Deflagration is uncontrolled rapid burning which is only slightly less rapid and violent than an explosion.
The label statement "DO NOT add water to the tablets" is both legally enforceable and sound advice.
The reaction of aluminium phosphide tablets is riskier when they are wet, and even more risky in the presence of a wet acid environment. This makes the recent practice by some of pushing the tablets into an orange and rolling it down the burrow a recipe for potential disaster, as the wet, acid environment inside the orange is more likely to start a deflagration reaction.
No rabbit is worth losing your fingers over, and in any case, there is no more phosphine liberated by the tablets stuffed in an orange than if they were simply placed down the burrow and the entrance sealed.
The moral of this story is to apply the principles of Integrated Pest Management, use an aluminium phosphide product approved for rabbit control and to use the product according to the label directions.
Reporting spray drift
Have you experienced spray drift of agricultural chemicals from a third party?
Chemical users have a legal obligation to ensure that they manage their use of agricultural chemicals appropriately. Should a property experience spray drift, producers need know which authority to report the issue to.
Agricultural: If you suspect your pasture, crop, stock food or livestock has been adversely affected by chemical spray drift, you need to phone the Department of Environment and Primary Industries Customer Service Centre on 136 186 and speak to your local Chemical Standards Officer as soon as possible.
Public health: Any personal or public health concerns relating to spray drift (e.g. spray drift over houses/people) should be reported to the Environmental Health Officer from your local council.
If you have any concerns regarding personal health and exposure to chemicals, you should seek medical advice from a doctor as soon as possible. For emergencies people should contact the Poisons Information Centre on 13 11 26.
Environmental: Issues relating to spray drift and water ways or land that is not used for agricultural purposes (e.g. pollution, contaminated land and chemical misplacement), are investigated by the Environmental Protection Authority (EPA) Victoria and can be reported via 1300 EPA VIC (1300 372 842) (24 hour contact number) to Pollution Watch Line (24 hours):
- Melbourne Metropolitan Area - (03) 9695 2777
- Outside Metropolitan Melbourne - 1800 444 004
$2000 fine for exceeding maximum chemical residue levels in calves
Leon Watt, Regional Animal Health Officer
A Warrnambool area man in charge of livestock pleaded guilty on 18 December, 2012 to several charges relating to the detection of antibacterial residues in a carcass that exceeded national maximum residue limits (MRLs).
The Warrnambool Magistrates Court was told that during May 2011, dairy calves were sold accompanied by national vendor declaration (NVD) indicating they complied with chemical withholding periods.
The livestock were later processed and, as part of a sampling program, tested for a range of agricultural chemicals and veterinary drugs. The results indicated one calf had levels of antibacterial residues that exceeded the MRL.
Livestock sold exceeding MRLs threaten access to Australia's major export markets, which are underpinned by stringent chemical residue requirements. Livestock producers need to ensure that any animals made available for slaughter comply with withholding periods and export slaughter intervals.
This is underpinned by maintaining the required chemical use records, including documenting details such as product trade name, species, identification number, location of animals and dates of first and subsequent treatments. In this case, there were no chemical records maintained and no way of determining which calf had been treated and when. Withholding periods are legally binding and are printed on chemical/drug labels.
In handing down the findings, the magistrate said "the threat of damage to trade reputation or loss of such a major export trade from such a high level detection of drugs in a food product was disturbing". He also took into consideration the general risk that Australian meat exporters could have suffered exceptional financial losses were they the vendors of such product to any international markets.
Dichlorovos grain protection products suspended
The Australian Pesticides and Veterinary Medicines Authority (APVMA) has suspended the labels of six dichlorvos products used for grain protection from 1 March 2013 until 3 March 2014. Additionally, the APVMA has issued new permit instructions for use which are in line with the findings of the dichlorvos review. Both are available on the APVMA's website.
The suspensions have been put in place to address potential human health risks.
Dichlorvos is an organophosphorus insecticide, anthelmintic and acaricide used for agricultural and veterinary pest control. It is used for disinfestation of grain and for insect control in grain storage facilities.
The APVMA began its review of dichlorovos in December 1996, following concerns relating to public and occupational health and safety, the environment, residues and trade. The dichlorovos summary report published in March 2011 found there was insufficient data relating to the protection for users of products and occupational exposure, exposures arising from some domestic uses, and residues in some food commodities.
The APVMA also found that the safety directions on dichlorvos product labels did not conform to current safety standards and labels did not contain adequate information to protect the environment.
The APVMA has issued two permits for dichlorvos products listed above (PER14075 for all products except Insectigas-D DDVP Insecticide, and PER14076 for Insectigas-D DDVP Insecticide), which contain instructions allowing the use of these products for grain protection subject to restrictions, which must be followed.
|Insectigas-D DDVP Insecticide||BOC Limited|
|David Grays D.D.V.P. 500 Insectide||David Gray & Co Pty Limited|
|Divap 1140 Insecticide||United Phosphorus Ltd|
|Divap 500EC Insecticide||United Phosphorus Ltd|
|Imtrade Dichorvos 500 Insecticide||Imtrade Australia Pty Ltd|
|Barmac Dichlorvos 500 Insecticide||Barmac Industries Pty Ltd|
All suppliers must provide to the person taking responsibility for the supplied product with:
- a copy of the relevant permit in full (currently PER14075 or PER14076) setting out the conditions and instructions for use, and
- supply product with a copy of the instructions contained in the permit securely affixed to each container of product.
The suspended products can only be used according to the instructions contained in the relevant APVMA permit, hence users must read and understand the new instructions before using or handling the product. Failure to comply with these instructions attracts a penalty under section 55(4) of the Agvet Code. The penalty is 300 penalty units (currently $33,000).
For further information on the dichlorovos suspension and permit requirements, speak to your local chemical reseller or visit APVMA.
Cross contamination: an industry-wide issue
Steve Field, Senior Chemical Standards Officer
Cross contamination can occur when produce unintentionally comes into contact with an agricultural chemical (excluding spray drift). This can occur in a variety of ways. The following real life scenarios illustrate how easily cross contamination can occur and be prevented.
A fruit grower grew a variety of fruit, including apples, pears and quinces. The grower first harvested most of the quinces from the property and stored them in a cool room.
The grower then harvested the apples and pears. To reduce losses from superficial scald, the grower dipped them in a diphenylamine (DPA) product, using the on-label rate. Due to lack of space in the cool room, the grower stored the dipped apple and pear bins directly on top of the quince bins. The bins were still wet and dripped dip solution onto the quinces stored below.
The quinces were analysed by the Department of Primary Industries (DPI) as part of its residue monitoring program. The results found that the quinces contained 0.032 mg/kg of DPA, which is a relatively small amount. As DPA is not registered for use on quince, there is no corresponding Maximum Residue Limit (MRL) in place, hence any residue is unacceptable.
The traceback investigation found that the likely cause of the residue was how the grower had stored his produce post harvest. This demonstrated a lack of understanding on how cross contamination may occur.
Apart from the DPA solution dripping onto the quinces, DPA also has the potential to volatilise (turn into a gas) whilst in cold storage. The volatilised DPA can be reabsorbed into untreated fruit, like quinces or organic apples, which may also cause unacceptable residues.
The volatilisation and reabsorption of DPA can create residue concerns for export markets. For example, the European Union is proposing to lower their MRLs for DPA on apples and pears. If adopted, this will mean that fruit destined for the EU cannot be treated with DPA according to current practices. Growers must also ensure that fruit is free of any unacceptable DPA residues. This may require growers and coolstore operators to pay closer attention to the thorough decontamination of cool rooms and segregation of fruit destined for the domestic and export markets.
A fruit grower grew a variety of fruit including apples, pears and lemons. The grower dipped his apples and pears with DPA and iprodione. Products containing iprodione are registered for the control of storage rots in apples and pears.
The grower dipped the pears and then immediately packed them out on his packing line. Directly after this, the grower packed out the lemons.
The lemons were analysed by DPI as part of its residue monitoring program and found to contain 0.044 mg/kg iprodione. Although this was a relatively small amount, iprodione is not registered for use on lemons. As there was no corresponding MRL, the residue was unacceptable.
In this scenario, the components of the packing line were not dismantled and tested for residues. It was thought that the wax brushes had retained some of the iprodione from the treated pears, which may have caused the residue. The unacceptable residues could have been avoided if the packing line had been decontaminated after the pears were packed.
Recently, there have been instances where grain (e.g. wheat, barley and field peas) from several properties has been found to contain residues of the fungicide, flutriafol. Flutriafol products are registered for the control of certain fungal diseases on various grain crops. In Victoria, it is often applied to fertiliser and used to treat grain at the time of sowing.
In some cases investigated by DPI, grain had become contaminated via structural transferor direct contact (e.g. through use of an auger, silo or truck used previously for storing treated fertiliser or seed, which was not decontamined after use).
In both cases, better decontamination of equipment used for both grain and fertiliser handling would have addressed the risk of contamination. Where possible, it may even be appropriate to use separate equipment for grain and fertiliser.
With the recent marked increase in container exports, it's essential to manage any contamination issues to reduce the risk of unacceptable residues occurring as this may lead to major market access issues.
In each of these scenarios, the individual growers were encouraged to change their practices to minimise the risk of cross contamination occurring again. DPI has also engaged various industry bodies that represent these growers to help raise awareness of this issue and ensure that other growers are aware of these risks.
Spray notification counts
People are becoming more concerned about agricultural chemicals being sprayed close to sensitive areas such as schools and hospitals - particularly when aircraft or mister sprayers are being used. Similarly, neighbouring properties can be concerned by chemicals being applied on adjoining land, particularly if they grow herbicide sensitive crops, graze livestock or grow organic produce.
These concerns are often due to a lack of information. This can be alleviated through good communication between the land manager/ occupier of the area to be sprayed/baited, their neighbours and sensitive property management (e.g. school principal, site manager).
Spraying within 200 m of a school, hospital, aged care service or children's service
To address some of these concerns, notification laws apply when spraying agricultural chemicals by aircraft or mister sprayers (e.g. orchard sprayers, air blast sprayers) within 200 m of a school, hospital, aged care service or children's service (e.g. kindergarten or child care centre). Notification laws do not apply if chemicals being applied by other forms of equipment, such as a boom sprayer.
At least 12 hours before spraying is to occur within 200 m of these facilities, the land manager/occupier of the area to be treated must make every reasonable effort to inform the school principal/site manager of:
- the name of the agricultural chemical to be used
- the location of the proposed spraying
- the proposed time, date and duration of spraying.
Equipped with this information, principals, site managers other staff can take any precautionary measures required to ensure the wellbeing of people under their care.
While it's not mandatory, it's good practice to inform neighbouring properties of your intention to spray agricultural chemicals, especially if you're going to spray near a sensitive crop or area. This provides them with the opportunity to discuss any issues they may have, take protective measures on their property and can help lower misunderstandings.
The Department of Environment and Primary Industries (DEPI) has developed an agricultural spraying notification template that chemical applicators may use to notify principals, site managers and neighbours of their intention to spray. This can be downloaded from www.agriculture.vic.gov.au/chemicaluse from the 'Application forms' page.
If there is an issue regarding a land manager/occupier not meeting their notification obligations, please contact your local Chemical Standards Officer via the DEPI Customer Service Centre on 136 186.
The bane of our lives
Jo Robinson, Leading Chemical Standards Officer
Last year, the Department of Primary Industries (DPI) alerted farmers in the Mallee and along the Murray Valley, north of Swan Hill, that the invasive weed, Flaxleaf fleabane (Conyzabonariensis – a.k.a 'Ragweed') was spreading rapidly towards their properties and in many cases, increasing its level of infestation.
Fleabane is a difficult weed to control in these areas. Fleabane infestations have been moving south over the 2012-13 summer, and the weed now appears to be well established as far south as Bendigo and Maryborough.
Fleabane has been around as isolated plants or in scattered patches for many, many years. The current infestation levels are the product of the wet summers of 2010 and 2011, which provided suitable conditions for seeds to establish and actively grow.
Fleabane is often first seen along linear corridors – roads, railways, and rivers, where it gains a foothold before spreading into nearby land. While infestations in pasture are rare, fleabane readily infests cropping land if effective controls measures are not taken. Fleabane can grow in impoverished situations, is drought tolerant, and spreads rapidly – a feature it shares with other members of the daisy family.
There are a number of herbicides approved for the control and/or suppression of fleabane, but none are selective for fleabane alone. When considering which herbicide to use, always assess the risk posed to any valuable plants nearby and rotate between different herbicide groups to avoid resistance issues.
Fleabane control is most effective when young, actively growing plants are targeted early in the growing season. Trying to control large, mature plants late in the growing season is often unsuccessful.
Using integrated weed management principles to attack this weed is a necessity, as relying on a single control method may be ineffective. Experience shows that it is vital that you keep the pressure on fleabane throughout its life cycle and apply with ongoing control measures and to reduce the seed bank by effective controlling weed survivors.
For information on how to tackle fleabane on your property, contact your local chemical reseller or agronomist.
Store farm chemicals correctly
There are many good reasons to store agricultural chemicals correctly. Correct storage helps prolong the shelf life of chemical products and also protects the health of people, animals and the environment.
Chemical product labels and Material Safety Data Sheets (MSDS) contain storage directions that should be followed. Collectively, the chemicals on most farms should be stored according to 'The Storage and Handling of Agricultural and Veterinary Chemicals' (Australian Standard AS 2507 – 1998). This can be purchased from SAI Global. Most farms have quantities and chemical types that are classified as 'Minor Storage' under this standard. If the quantity of chemicals stored on a property exceed 1000 kilograms or litres combined, there are additional specifications to comply with, such as the Dangerous Goods Act 1985 and Dangerous Goods (Storage and Handling) Regulations 2012.
A chemical storage area can be:
- an outdoor area that has a security fence and roof
- a free-standing, roofed building (e.g. shed)
- a room or enclosure or area within a building
- a building that is attached to another building.
Chemical storage areas must be located:
- at least 15 m from the boundary property
- 10 m from buildings occupied by people or livestock
- 3 m from unrelated work areas (e.g. offices and amenities)
- 3 m away from flammable materials and fuel storage
- 5 m from any watercourse, body of water, drain or sewer.
The entry point should have signage stating "Chemical Store Keep Out" – "Authorised Staff Only" and "No smoking" "No naked flames".
When storing agricultural chemicals in small quantities, you should:
- maintain a list of all chemicals kept in storage
- store chemicals in a cool, well-ventilated area that is lockable, away from direct sunlight (e.g. in a shed), has an impervious floor and shelving and is bunded to contain spills
- avoid stockpiling chemicals by only purchasing them when the need arises
- store chemicals in their original labelled containers (if labels come off, re-label the container)
- keep all MSDS in a register nearby for easy access
- never store chemicals in food or drink containers
- separate incompatible/different chemical types to avoid cross-contamination (e.g. store liquids close to floor level to minimise the risk of spills, store solids above liquids, segregate flammable products from non-flammable products by at least 3 m, segregate veterinary chemicals from all other chemicals)
- never store chemicals with seeds, fertilizers, protective clothing or stockfeed
- ensure running water, first aid and other facilities as required by the MSDS are available.
It's good practice to keep a spill kit in your storage area that contains absorbent material (i.e. 'kitty litter'), hydrated lime, a shovel and broom and containers to store contaminated substances used to treat a spill. There should be a sign inside the storage area indicating the spill kit's location.
You should also keep an appropriate extinguisher directly outside the storage area that is easily accessible in the event of an emergency.
For more information on storing agricultural chemicals, contact WorkSafe on 1800 136 089 or Department of Environment and Primary Industries on 136 186.
Chemicals should always be safely locked away from children, unauthorised people and animals.