Came across this table online from the Virginia and Maryland Commercial Fruit Grower Spray Bulletin. It may be helpful when considering your choice of sprays.
I find it interesting that glyphosate (Roundup) and Imidan are considered to be among the least toxic from skin contact.
pesticide and fungicide toxicity to skin.pdf (116.4 KB)
Thanks Chris for posting that. Helpful to be able to view the relative acute oral and dermal toxicity of those pesticides.
Because some may not be aware, I’ll mention that every pesticide has a “signal word” on the label. The signal word is intended for users to determine, at a glance, the relative acute danger of the pesticide being used. The word applies only to the concentrate, not the diluted spray solution.
The four words are in least to greatest:
Caution
Warning
Danger
Danger (Poison)
The words are based on acute oral poisoning, eye and skin damage. I think most consumer marketed products have a Caution signal word, but a few have a Warning (Captan 50). A more severe signal word demands more respect for the concentrate.
However, the signal word shouldn’t be used to evaluate the safety of the residue on the fruit. Severity of the signal word doesn’t correlate w/ the safety of the product on the fruit. It’s largely the level of concentration of the active ingredient which determines the signal word.
I mentioned Captan 50 (50% active ingredient) which has a Warning signal word. However, Captan 80 (80% a.i.) has a Danger word. Nevertheless, both formulations are considered relatively safe once they are on the fruit and have a 0 PHI. Captan is even approved for post harvest dip in apples. I’ll borrow a phrase from Alan, “The gov. is cool w/ you eating it.” (I still laugh when he came up w/ that sort of sanguine, partly sarcastic phrase.)
So the signal words (and the chart you linked) may be useful for determining acute risk in handling the concentrate, but not so much so for evaluating the risk of consuming the sprayed fruit, which of course is considerably less risk.
Olpea, it seems odd to me that Captan 80 would include a “Danger” signal word when the chart lists it as being one of, if not, the safest fungicides in terms or dermal and oral toxicity. The zero PHI further brings that wording into question imo.
The only thing I can think of is inhalation or dermal contact hazards from the dust of the WP versions. The 80 WDG version I have is dust free and I handle it with my bare hands sometimes. As far as consuming the fruit treated with sprays…what effect does additional or inclusive stickers have on residues and even dermal contact for that matter? I may be remembering incorrectly, but I believe Captan is comparatively safe from a residue standpoint as well. Also, as you said, Captan is often used on apples (and maybe other fruit too) as a pre-storage treatment. I totally do not get strong signal wording for Captan. Myclo appears to be more dangerous. The Methomyl we all talked about the day before yesterday seems to be the most dangerous of all sprays in regards to oral and dermal toxicity. What am I not getting here?
From the chart data it seems that the copper I spray is as dangerous as any of my sprays and I believe it is approved under certified organic programs. I realize this is a different thing, but I think that would surprise most people. I’d bet that copper has residue issues too, and it is sprayed in low concentrates on fruit. I just read about it the other day when reading about BR control.
I was surprised to see micronized sulfur was not included on the list (unless I overlooked it). I think it’s oral toxicity is about zero, but it can and does cause skin irritation and does pose some inhalation hazards as a dust.
I was pleased (and a bit surprised) to see Phosmet is pretty safe in comparison with it’s peers. It does look as though the synthetics (save for maybe Asana) might be a bit better in terms of safety in regards to the chart objectives. If the SI’s and synthetic pesticides are really capable of penetrating plant cellular tissue, one would have to wonder what prevents them from penetrating human skin tissue as well? The penetration would only need to be so very little before having the ability to enter the bloodstream.
This is useful not only in its obvious ramifications to pesticide use but to demonstrate how poisons are often easily absorbed by the skin (and also the lungs). There is excessive focus by people on the oral entry which distorts the perception of the relative importance of agricultural pesticides.
The public is so much less concerned about vehicular exhaust, for example, even though some of the serious health consequences of breathing air high in its content are supported by a lot of data.
Things like lead can often come into contact with people if they are not aware of the skins ability to absorb the stuff. My pellets for my air gun have a warning about not handling them on the container they come in.
Very interesting and useful information. Most of the chemicals with a high level of dermal toxicity are pellets used to kill moles/voles (Ramik, Rozol, ZP).
Also Bordeaux mix has a high rating for dermal toxicity. It was used for centuries on grapes in France. Was considered very safe at one point and was suggested as an alternative to chemical fungicides. Some versions used to be ORMI approved for organic production.
Useful list, thanks Chris.
Sulfur is on the second page, listed as S,S.
Glyphosate has been getting plenty of bad press. Here is just one example
Apple,
You are right to recognize that. The reason the 80% has a “Danger” word is not due to oral toxicity or skin absorption, but because the concentrate can cause permanent blindness if it gets into one’s eyes. That’s part of the criteria the EPA uses to define the signal words.
A good question about the stickers. Without a doubt they do help retain the compound on the sprayed surface in the face of rain, but that wouldn’t affect the re-entry interval (REI) because those are calculated based upon no rain anyway, as are pre-harvest intervals (PHI).
The only sticker I know of which could come into play here is Nu-film 17 which claims the sticker has UV protection to keep the pesticide from breaking down in sunlight. However, it has it’s own PHI of 30 days no matter the insecticide/fungicide it’s used with. If I recall, it doesn’t say anything about REI though.
Alan has mentioned the PHI might need to be extended w/ Tactic, but I’ve only used it a season and don’t know as much about it as Alan does.
OK then…well there’s a question I’m glad I asked. I didn’t know that, and I thought I read the entire label…sometimes I speed read though…haha.
I knew there had to be a good answer Olpea…and I knew you would know what it is. Thanks.
Olpea…another question. I thought Thiophanate Methyl (Topsin M) and Methomyl (Lannate) were the same thing? I just did some reading on them the other day and the terms were used interchangibly, yet the chart shows them as two different chemicals with wildly different toxicity levels. Topsin seems to be rather benign, while Lannate appears to be awful in terms of safety.
I only noticed this now because I didn’t realize there was a second page until Danzeb mentioned it.
Apple,
Although it looks like you already discovered this, Lannate and Topsin are different. Topsin is a fungicide while Lannate (Methomyl) is an insecticide. Methomyl used to be a more common insectide. I remember using it in a fly bait called Golden Malrin (they’ve since changed the formulation). Now Methomyl is a restricted use pesticide. I’ve never used it on my fruit.
Perhaps the assumption both compounds were the same was the result that both are carbamates (like the insecticide Sevin, or the fungicide Captan).
Or perhaps it’s just that the names are somewhat similar. That’s happened to me before. Years ago I thought Imidan and Imidicloprid were the same.