Four Point Seven Millimetres: The Application Category That Is a Hand Position

1. Introduction: a category with no chemistry in it

Most of what this journal writes about pesticide use concerns what is in the container. This article concerns where the tip is pointed, which turns out to determine the legal character of the application.

1.1 Not a matter of degree

The category is lost entirely, rather than diminished.³

1.2 What this article argues

That an application category with real legal weight is decided by hand position at millimetre scale, that one adjacent category is bounded per application and unbounded in aggregate, and that a crack deposit ages under conditions the registration protocol does not test. Sections 4, 14 and 9 are the case.

2. The definition

Which is consistent across the sources that state it.

An application in which the pesticide is only released within the crack and crevice and does not leave a deposit on exposed surfaces.²

2.0b Two words doing different work

A crack is a gap in a continuous surface, produced by settlement, shrinkage or damage. A crevice is a gap between two separate elements that were never joined: a cabinet against a wall, a kickplate against a floor, equipment against a slab.

The second kind is far more common in a building and is created by construction rather than by failure, which means it cannot be repaired away and will be present in a new kitchen as reliably as in an old one. That distinction is ours and it explains why the category is so central to structural work.

2.1 With the locations enumerated

Openings such as expansion joints, between levels of construction, between different elements of construction, between equipment and floors, or into openings leading to voids such as hollow walls, equipment legs and bases, conduits, motor housings, and junction or switch boxes where insects may be present.²

2.2 And a quantity implied

Small amounts, in every version of the definition we found.²

3. And its sharp edge

The operative clause is the negative one.

Not where the product went, but where it did not go. Applicators are instructed to avoid splashing, spraying or dusting the pesticide out of the crack.³

3.0b And the instruction is about technique rather than quantity

Splashing, spraying and dusting out of the crack are three ways of failing, and none of them is a matter of using too much product. They describe pressure, angle and how the tip is withdrawn.

3.1 So the category is defined by an absence

Which is harder to achieve than a presence and harder to verify afterwards.

That framing is ours.

4. Which carries a legal consequence

In one setting particularly.

Some products allow only crack and crevice applications in food areas, since an insecticide deposit on an exposed surface may be in violation of federal law.¹

4.1 The same product, the same rate, the same room

Lawful or unlawful according to whether a small amount of it landed on the outside of the opening.¹

4.1b And the rule is about food contact rather than about dose

The concern behind restricting exposed-surface deposits in food areas is contamination of food and food-contact surfaces, which is a question of where material can end up rather than of how much was used. A small deposit in the wrong place matters more than a larger one in the right place.¹

Which is why the category is absolute rather than graded, and it makes the rule coherent even though it is unverifiable. That reading is ours.

4.2 Which is a compliance standard resting on manual precision

Rather than on a decision anybody records, and our article on the label as a legal instrument described labels as binding without examining a requirement of this kind.

5. The size of the target

Which is the fact everything else sits on.

The German cockroach prefers to hide inside a crack only 3/16-inch (4.7 mm) wide.¹

5.0b And the preference is not arbitrary

An insect that fits a gap tightly is in contact with surfaces on both sides, which is the thigmotactic preference our harbourage articles have described for this species. A gap much wider offers less contact and a gap much narrower excludes the animal, so the preferred dimension is a property of the body rather than of the building.

Which means the target dimension does not vary between properties, and a technician who has learned what a treatable opening looks like has learned something transferable. That reading is ours.

5.1 That is narrower than most spray tips are precise

And the definition requires the material to enter it without landing beside it.

6. What that means for the technician

Our reading, and it is not a criticism of technicians.

A compliance category that depends on a few millimetres of tip placement, repeated dozens of times per property, in cabinets and behind equipment, under time pressure, will be met imperfectly by anybody.

6.0b The comparison with a dose is worth drawing

A dilution rate is checkable: the concentrate and the water are measured, and an error is discoverable from the mixing record. A placement is not measured at all, and the only evidence it ever existed is the technician's account of it.

So two requirements of equal legal standing have completely different verification properties, and the one that cannot be checked is the one the category is named for.⁹

6.1 And nothing records how well it was met

A service report states that a crack and crevice application was performed. It does not state whether any deposit landed outside, which is the thing the definition turns on.

6.2 Which makes this a credence attribute in the strict sense

Our economics articles used that term for qualities the buyer cannot verify after purchase. Here the employer and the regulator cannot verify it either, shortly after the technician has left the room.

7. Why the method is preferred

And the reasons are good.

It is a targeted application that places the product where the pests are hiding and reduces insecticide exposure to non-targets; because it is targeted, less insecticide can be used; and a regulator's information centre is cited for the observation that label-directed crack and crevice applications reduce general surface contamination compared with broadcast sprays.¹⁸

7.0b And the reduction in quantity is not incidental

Placing material where the animals are means less of it is required for the same exposure, because none is spent covering surfaces nothing walks on. A broadcast application achieves contact by making contact probable across a large area; a targeted one achieves it by putting the deposit where contact is certain.

Which is the same efficiency argument our integrated management articles make about inspection generally: knowing where the animals are substitutes for treating everywhere they might be.

7.1 Which is the whole case for it and we accept it

Less material, placed where the animals are, with less residue where people are.

8. The protection claim

And this is the one that turned into an argument.

Applications last longer since the product is protected from air currents, light, heat and moisture.¹

8.1 Which is plausible on its face

Those four are the principal degradation pathways for a surface deposit.

9. Which sits oddly against the registration protocol

Our observation, and it follows from an article we published three pieces ago.

The efficacy testing guidance for residual claims specifies ageing of treated surfaces outdoors in direct sunlight and precipitation, or indoor simulation including photoperiod cycles with a light source containing both ultraviolet bands and periodic simulated rain, on a porous and a nonporous substrate.

9.1 Every one of those stressors is an exposed-surface stressor

And a crack and crevice deposit is by definition not on an exposed surface.²

9.2 So the tested condition and the applied condition differ systematically

The residual testing describes a deposit on a panel in weather. The application places material in a dry, dark, still opening.

10. And the direction of the error

Which matters and is unusual in this journal.

If the trade claim in §8 is right, the protected deposit outlasts the tested one, so the registration data understates the residual life of the application as actually made.¹

10.1 Which is conservative rather than permissive

A rare case where the gap between test and practice runs in favour of the claim rather than against it.

10.2 With the obvious caution

We have the trade claim and the testing protocol and no measurement comparing the two. An untested deposit lasting longer is a hypothesis, and the indoor porous substrate in the protocol is the nearest available comparison rather than a match.

10.2b Which would be straightforward to test

Treated panels aged in an enclosed dark cavity against treated panels aged under the protocol conditions, assayed at intervals against the same species. That is a laboratory exercise rather than a field study, and nothing in it is novel except the question.

We record it because §30 says the comparison does not exist, and it is worth noting how small the missing study is.

10.3 And a second consideration cuts the other way

A deposit nothing walks on is also a deposit nothing contacts. Residual life and residual efficacy are different quantities, and our substrate article argued the second depends on availability as much as on persistence.

11. The other categories

Since crack and crevice is one of several.

Training material lists band, basal, broadcast, directed spray, foliar, wick, spot treatment, soil application, soil incorporation, soil injection, tree injection, space treatment, and crack and crevice of buildings.⁶

11.0b And the list itself is revealing

Thirteen methods, of which one concerns buildings. Applicator training, the certification literature our earlier article examined, and the regulatory categories all developed around agriculture, with structural work appended.⁶

Which is consistent with what this journal has found repeatedly: the conceptual apparatus of pest control was built for fields and adapted to rooms, and the adaptations are where the awkwardness sits.

11.1 Most of those are agricultural

Structural work uses a handful: crack and crevice, spot, broadcast or surface, void treatment, and space treatment including fogs, mists and ultra low volume applications.²

11.2 And space treatments are restricted in some specifications

One contract form restricts applications to exposed surfaces and space sprays, including fogs, mists and ultra low volume applications, to unique situations where no alternative measure is practical, with a formulation of least exposure potential to be chosen if one becomes necessary.²

12. Spot treatment has a number

Which surprised us.

In a federal response letter on pyrethroid label language, spot treatment was indicated to be defined as 2 square feet, with reference to a registration notice.⁴

12.0b Two square feet is smaller than it sounds

A square roughly seventeen inches on each side, or a strip a foot wide and two feet long. Against a kitchen floor or a foundation wall it is a modest patch rather than a region.⁴

12.1 States supported the determination

As appropriate where no state-level definition exists.⁴

13. And two things it does not have

Stated in the same paragraph.

Questions had arisen about what constitutes a spot and crack and crevice treatment, and whether there are limitations to the number of or distance between these kinds of treatments; states agreed that the distance between and number of spot treatments is to be left to state discretion, so long as the intended goal of limiting runoff into waterways is considered.⁴

14. Which leaves the aggregate unbounded

Our reading.

Each spot is capped at two square feet. The number of spots is not capped federally, and neither is the spacing. A sufficiently large number of compliant spots covers an arbitrarily large area.⁴

14.0b And the contrast with crack and crevice is instructive

Crack and crevice is bounded by a physical condition: material cannot be outside the opening, and there is only so much opening. Spot treatment is bounded by an area per event with no limit on events.

One definition is self-limiting because the building limits it. The other relies on a number that constrains each act and not the sum of them, which is a different kind of rule doing the same job.

14.1 Which is the same structural problem as a rate expressed per application

Where the per-event limit is specified and the frequency is not, a subject our reentry interval and label articles have approached from the timing side.

14.2 And the reason the question arose is instructive

It was raised in the context of runoff into waterways, which is an aggregate quantity. A definition that bounds each event and not the total is poorly suited to an aggregate concern.⁴

15. We are not alleging abuse

And want to be clear about it.

Nothing we found suggests applicators routinely treat large areas as sequences of spots, and the letter records the states raising the question rather than reporting a practice.⁴

15.0b And the states raising it were the enforcers

The question came from officials who would have to decide whether a given treatment complied, which is the position from which an unbounded aggregate becomes a practical difficulty.⁴

15.1 The point is about what the definition controls

Not about what anybody is doing with it.

16. The foundation question

A smaller episode in the same letter.

Concerns were raised over what constitutes a foundation, typically the slab or other supporting structure, not the vertical wall surface, and the federal clarification indicated the intent is any material on the vertical side of the structure.⁴

16.0b Which matters for perimeter work specifically

Exterior perimeter treatment is among the most common structural applications, and whether the labelled surface is the slab or the wall above it determines both where the material goes and how far it has to travel to reach ground.⁴

16.1 So the term on the label meant the opposite of its ordinary sense

To the people enforcing it, until a letter said otherwise.⁴

17. What that episode shows

Our assessment.

A label term that state regulators read one way and the federal agency intended another way is not a drafting curiosity. Every application made under the state reading was made to a different surface from the one intended.

17.0b And the error would have been systematic

A misreading of a defined term is not a slip that varies by operator. Everyone following the state reading treated the same wrong surface, consistently, for as long as the reading stood, which makes it a different class of problem from ordinary application variation.⁴

17.1 And it was resolved by correspondence

Which is not a document an applicator reads.

18. How labels are actually read

Stated by a regulators' association, in writing.

Although applicators are responsible for reading the entire label, it is a reality that a majority of applicators rely primarily on the Directions for Use section.⁴

19. Which is a remarkable thing to see in writing

Our view.

The legal position is stated first and conceded to be the legal position. The empirical claim follows it and contradicts the behaviour the legal position assumes.⁴

19.1 Our label article treated the document as binding in full

Which it is. This adds that the people bound by it are understood by their regulators to read part of it.

20. And the recommendation that follows from it

Practical, and an accommodation rather than a correction.

Because the environmental hazards language is applicable to actual use, the association recommended it be placed in both sections, suggesting the most pertinent statements related to preventing runoff be put in the directions for use in order to gain more consistent compliance among applicators.⁴

20.0b And it concedes something about enforcement

A rule that most of the regulated population does not encounter is not enforced by being written down. Repeating it where people look is an acknowledgement that placement in the document determines compliance more than legal status does.⁴

20.1 Designing the document around how it is read

Rather than insisting it be read as written, which we think is the correct response and worth noting as such.

21. The exposure estimate

A separate finding from the same territory.

A federal standard operating procedure for residential exposure assessment covers crack and crevice and broadcast treatment, estimating potential doses to people from inhalation and dermal contact during indoor applications, with the method for estimating handler inhalation doses relying on surrogate data from a database, to be used in the absence of actual field data, or as a supplement to estimates based on field data.⁵

21.0b And the scenario being modelled is a householder

The procedure estimates doses to people applying the product themselves indoors, which is the consumer aerosol and consumer concentrate case rather than the professional one. Our article on consumer products assessed what those products achieve and not what applying them delivers.⁵

21.1 Surrogate data in the absence of field data

Which is a candid statement of what the estimate is.⁵

22. Which our applicator article should have noted

A correction to our own work.

Our article on applicator exposure routes and glove failure examined occupational dose. It did not establish how the underlying exposure estimates are generated, and this source says that for indoor application they rest on surrogate data where field data is absent.⁵

22.1 Which does not make the estimates wrong

Surrogate databases exist because measuring every scenario is impractical, and the procedure says so openly.⁵

22.2 It does affect how confidently a number should be quoted

Which is the standard this journal has applied to other people's figures and should apply to the ones underpinning its own occupational article.

23. When the category is the wrong choice

Crack and crevice is not the best choice for all pests or all situations, and if the pest you're trying to control isn't known to frequent cracks and crevices, you're wasting your time, with the example given of treating bathroom cracks against drain flies whose larvae live inside drains and pipes while the adults rest on walls and ceilings.¹

24. A compliant treatment of nothing

Our phrase for it.

A crack and crevice application made correctly against a pest that does not use cracks satisfies every requirement the category imposes and accomplishes nothing.

24.0b Which is the inverse of the failure our compliance articles usually describe

The familiar failure is an effective treatment made improperly: too much product, the wrong placement, an occupied room. This is a proper treatment that was never going to work, and only the first kind is detectable by anybody auditing the work.

24.1 And it is invisible to every check that exists

The label was followed, the placement was correct, the quantity was small, the record is accurate, and the only thing wrong is the diagnosis.

24.2 Which connects to our drain fly article directly

That article found the source of small fly problems in drain biofilm rather than in the room, and this is the same error described from the application side.

25. Droplet size, briefly

Since it governs everything about an outdoor application.

Guidance advises that the label and the nozzle manufacturer's guide help determine the best nozzle and pressure combination, that lowering a boom reduces off-target drift, that travel speed affects drift potential, that the nozzle should be kept close to the target with hand-held equipment, and that heavy rain and high winds affect droplet deposition.⁷

25.0b Which is a different problem from the indoor one

Everything above concerns placing material precisely in a small opening indoors. Droplet size governs the opposite situation: distributing material across an outdoor surface while keeping it from travelling where it was not meant to go.⁷

The two share only the underlying question of what fraction of what was released arrives where it was aimed, which is the quantity no application category specifies.

25.1 And sprays are sub-classified by droplet size in trade descriptions

With residual sprays depositing a film that remains toxic to crawling insects for days to weeks, contact sprays killing on contact and leaving minimal residue, and crack and crevice applications directing the tip into structural voids.⁸

26. With one claim we do not follow

And we raise it because we may be wrong rather than because we are confident.

The same guidance states that selecting a nozzle that increases droplet size will provide greater product coverage and decrease chances of drift.⁷

26.1 The drift half is standard

Larger droplets are less readily carried by air movement.⁷

26.2 The coverage half runs the other way on our understanding

A fixed volume divided into larger droplets produces fewer of them, and fewer droplets over the same area is less coverage rather than more. Coverage and deposition are different quantities and the sentence may be using coverage to mean the second.

26.3 We flag it rather than correct it

The source is training material, we did not locate the underlying reference, and a reader following that sentence as written would expect something we think does not follow.

27. What we would change

Three things, all cheap.

Record the category, not just the product. A service record stating crack and crevice, spot or surface makes the compliance question answerable later.

Ask whether the pest uses cracks before choosing the method. Section 23.¹

And read the environmental hazards section. Because a regulators' association has said in writing that most applicators do not, and the language there applies to actual use.⁴

27.1 And the first of those is the only one with any cost

Recording the category adds a field to a service record. The other two are decisions a technician already makes, taken deliberately rather than by default.

28. Our own position

The disclosure.

We make crack and crevice applications constantly, and §6 says the standard they are held to depends on millimetre precision that nobody verifies, including us.

28.0b And the awkward version of the finding

If placement accuracy is unverifiable and unrecorded, then the difference between a firm that trains for it and one that does not is invisible to a customer choosing between them. That is our credence-good argument applied to an attribute we would like to be judged on, and it cuts against the possibility of being judged on it.

28.1 Which is an argument for recording more, not for claiming less

The method is good and the case for it in §7 stands. What is missing is any record of how well the defining condition was met.

28.2 And §22 corrects one of our own articles

On the provenance of the occupational exposure numbers it relied on.

29. The Manitoba position

29.1 The definitions here

The two-square-foot figure and the federal clarifications above are American, and we could not locate Canadian equivalents for either the spot treatment area or the crack and crevice boundary.

29.1b And the terminology is in daily local use regardless

Crack and crevice, spot and broadcast are how the work is described in this city, on service records and in training, whether or not the underlying definitions were written for this jurisdiction. A term borrowed without its definition is a familiar hazard, and our article on commonly accepted methods in tenancy law found the same pattern in a different body of rules.

29.2 Which matters because labels here are Canadian instruments

Our article on the label as a legally binding document set out that position, and the categories on a Canadian label are defined by Canadian guidance we were unable to find.

29.3 And that is the gap we would most want closed

Because §4's compliance consequence depends entirely on which definition applies.

30. Limitations and open questions

The sourcing is weak and mostly commercial. Of the sources here, one is a trade magazine, one a contract clause aggregator, one a study aid, three are commercial or training material, and two are agency documents.¹²³⁷⁸⁹

The definitional quotations come from a contract aggregator. Which reproduces clauses from agreements rather than from regulations, so the wording is how parties have written the definition into contracts and not necessarily the regulatory text.²

That is the most important weakness because §2 is the article's statement of the definition and §4 attaches a legal consequence to it, and neither is sourced to a regulation we read.

The 4.7 millimetre figure is a single trade statement. Presented without citation, and we did not find the underlying measurement of crack width preference in this species.¹

The residual argument in §§8 to 10 is unmeasured. We have a trade claim about protection and a testing protocol from a separate article, and no study comparing deposit persistence inside and outside an opening.

And we could not find any data on placement accuracy. How often a crack and crevice application leaves a deposit outside the crack is the empirical question this entire article depends on, and nobody appears to have measured it.

Sections 3.1, 6, 9, 10, 14, 17, 19, 24, 26 and 27 are our reasoning. The defined-by-absence framing, the credence attribute argument, the comparison between ageing protocol and crack conditions, the aggregate spot arithmetic and the compliant-treatment-of-nothing case are ours rather than sourced positions.

31. Conclusion

A crack and crevice treatment is defined by what it does not leave behind: the product released only within the opening, with no deposit on exposed surfaces.² Trade guidance puts the boundary absolutely, saying that as soon as there is pesticide on an exposed surface the application is not a crack and crevice application, and in food areas a deposit outside the opening may put the application in breach of federal law.³¹ The target is described as a gap about 4.7 millimetres wide.¹ So the legal character of an application, repeated dozens of times per property behind cabinets and equipment, is settled by where a technician holds a tip, and no record anybody keeps states how well that was managed.

The adjacent category is bounded in one direction only. Spot treatment has a federal definition of two square feet, while the number of spots and the distance between them are left to state discretion, which means the aggregate treated area is not constrained by the definition at all, and the question was raised in the context of runoff, an aggregate concern.⁴ The same letter records a term, foundation, that state regulators read as the slab and the federal agency intended as any material on the vertical side of the structure.⁴ And it contains a sentence worth preserving: although applicators are responsible for reading the entire label, a majority rely primarily on the directions for use, which is why the association recommended printing the same warning twice.⁴

Two things follow for us. A deposit inside a crack is protected from light, heat, moisture and air movement, which are precisely the stressors the registration ageing protocol applies to test panels, so the tested residual life and the applied residual life diverge, unusually in the conservative direction.¹ And the method's precision is also its failure mode: a crack and crevice application made correctly against a pest that does not use cracks satisfies every requirement the category imposes, is recorded accurately, passes every check that exists, and accomplishes nothing.¹ The only thing wrong with it is the diagnosis.

References

1. Article on what constitutes a crack and crevice treatment, published in a pest control trade magazine. Trade material written for practitioners, cited as attributed material. Source for the definition of a crack and crevice treatment as the application of a small amount of insecticide directly into cracks and crevices where insects hide or may enter, including application behind, between and under objects and into inaccessible small voids; for the statement that the German cockroach prefers to hide inside a crack only three sixteenths of an inch, given as 4.7 millimetres, wide; for the enumeration of typical treatment sites between cabinets and walls, behind countertop backsplashes, in hollow equipment legs or bases, behind kickplates, in drawer tracks, behind baseboards or mouldings, and between or under appliances; for the advantages claimed, namely that it is targeted and places product where pests hide, reduces exposure to non-targets, permits less insecticide to be used, and that applications last longer since the product is protected from air currents, light, heat and moisture; for the statement that some products allow only crack and crevice applications in food areas since an insecticide deposit on an exposed surface may be in violation of federal law; and for the disadvantage that the method is not the best choice for all pests or situations, with the example that treating bathroom cracks against drain flies will have little effect since the larvae live inside drains and pipes while adults fly and rest on walls and ceilings. https://www.pctonline.com/article/exactly-what-is-crack-and-crevice-treatment/
2. Dictionary entry aggregating definitions of crack and crevice treatment as written into contracts, published by a commercial contract clause database. A compilation of language from private agreements rather than of regulatory text, which we flag because this article's central definition rests on it. Source for the definition of a crack and crevice treatment as an application in which the pesticide is only released within the crack and crevice and does not leave a deposit on exposed surfaces; for the accompanying contract language restricting application of pesticide liquid, aerosol or dust to exposed surfaces and pesticide space sprays including fogs, mists and ultra low volume applications to unique situations where no practical alternative exists, with a formulation of least exposure potential to be chosen and named formulation types to be used only as a last resort, and such applications made only to unoccupied areas remaining unoccupied until treated surfaces have dried or longer where the label specifies; and for the variant definitions describing application of small quantities or amounts into openings such as expansion joints, between levels or different elements of construction, between equipment and floors, or into openings leading into voids such as hollow walls, equipment legs and bases, conduits, motor housings and junction or switch boxes where insects may be present. https://www.lawinsider.com/dictionary/crack-and-crevice-treatment
3. Study aid flashcard set covering a pesticide applicator training chapter on application techniques. Third-party revision material of unknown provenance summarising a training manual, flagged as a weak source and used for two operational statements. Source for the statement that as soon as there is pesticide on an exposed surface the application is not a crack and crevice application; for the instruction to avoid splashing, spraying or dusting the pesticide out of the crack; and for the description of dust application in thin layers to wall and cabinet voids using hand or power dusters, with hand dusters recommended to have a plastic tip to reduce shock risk near electrical outlets and conduits and the spout held uppermost, and power or plunger dusters used for large voids such as attics or crawl spaces. https://quizlet.com/349694641/chapter-8-application-techniques-flash-cards/
4. Letter from an association of state pesticide control officials concerning pyrethroid label language, archived on a federal agency website. A regulators' association document commenting on label drafting, and the strongest source in this article. Source for the observation that although applicators are responsible for reading the entire label, it is a reality that a majority of applicators rely primarily on the directions for use section, and for the resulting recommendation that language applicable to actual use be placed in both the environmental hazards and directions for use sections in order to gain more consistent compliance; for the record that questions had arisen about what constitutes a spot and a crack and crevice treatment and whether there are limitations to the number of or distance between such treatments; for the statement that in a federal response letter spot treatment was indicated to be defined as two square feet with reference to a numbered registration notice, that states supported this determination where no state level definition exists, and that states agreed the distance between and number of spot treatments is to be left to state discretion so long as the goal of limiting runoff into waterways is considered; and for the account of concerns over what constitutes a foundation, described as typically the slab or other supporting structure rather than the vertical wall surface, with the federal clarification indicating the intent is any material on the vertical side of the structure. https://19january2021snapshot.epa.gov/sites/static/files/2015-08/documents/aspcro-pyrethroid-ltr-12-001-0161.pdf
5. Standard operating procedures for residential exposure assessments, section on crack and crevice and broadcast treatment, archived on a federal environmental agency website. Agency methodological guidance. Source for the instruction that an assessor should consult the pesticide label to determine whether the scenario is appropriate and whether the label contains directions for use as a crack and crevice treatment or for use on carpets or hard surfaces; for the description of the procedure as providing a standard method for estimating potential doses homeowners may receive from inhalation and dermal contact during indoor crack and crevice and broadcast treatments; and for the statement that the method for estimating handler inhalation doses from pesticides used indoors relies on surrogate data from a named database and should be used in the absence of actual field data or as a supplement to estimates based on field data. https://archive.epa.gov/scipoly/sap/meetings/web/html/8sess3.html
6. Chapter on application equipment from a university extension pesticide applicator training presentation. Institutional training material. Source for the enumerated list of application methods, namely band, basal, broadcast, directed spray, foliar, rope or wick, spot treatment, soil application, soil incorporation, soil injection, tree injection, space treatment, and crack and crevice of buildings. https://rvpadmin.cce.cornell.edu/uploads/doc_551.pdf
7. Lesson on application procedures published by a commercial training provider. Commercial training material, cited as attributed material, and containing one claim this article declines to follow. Source for the guidance that the pesticide label together with the nozzle manufacturer's guide helps determine the best nozzle and pressure combination, that selecting a nozzle which increases droplet size will provide greater product coverage and decrease chances of drift, that lowering the height on a boom sprayer can reduce off-target drift, that high travel speeds may increase drift potential from an unstable boom, that the nozzle should be kept close to the target when using hand-held equipment, that heavy rain and high winds may cause drift and affect droplet deposition, and that a buffer zone should be left around sensitive areas. https://allpoints123.com/lessons/application-procedures-4/
8. Article on pesticide application types used by professional exterminators, published by a commercial pest control information site. Marketing-adjacent content, cited as attributed material. Source for the sub-classification of spray applications by droplet size, with residual sprays described as depositing an active ingredient film on surfaces that remains toxic to crawling insects for days to weeks, contact sprays as killing on direct contact while leaving minimal residue, and crack and crevice applications as directing the spray tip into structural voids to limit exposure to surfaces pests contact directly; and for its attribution to a national pesticide information centre of the observation that label-directed crack and crevice applications reduce general surface contamination compared with broadcast sprays, which we did not verify at that centre. https://nationalexterminatorauthority.com/pesticide-application-types-used-by-exterminators/
9. Pest control business glossary published by a commercial business listing site. Commercial content, cited as attributed material and used only for terminology in common trade use. Source for the usage examples distinguishing crack and crevice application from broadcast application and from void foaming, for the definition of dilution rate as the label-specified ratio of concentrate to diluent described as critical for efficacy, safety and compliance with the note that incorrect dilution can reduce efficacy and increase callbacks, and for the definition of drift as the movement of pesticide droplets or particles off the intended target area. https://dealstream.com/industry-guides/pest-control-businesses/glossary