Who Gets Hurt by Pest Control? Eight Years of Illness Reports
Key result: California recorded 135 pesticide illness cases linked to structural pest control from 2016 to 2023, against 128.5 million applications. 116 involved sulfuryl fluoride fumigation, which was 0.6 percent of applications: 15.2 cases per 100,000 fumigations, against 0.015 per 100,000 for everything else. Six people died, five of them after entering buildings under fumigation.
Two public records, joined for the first time
California investigates every reported pesticide illness. County agricultural commissioners look into each report, and the Department of Pesticide Regulation’s Pesticide Illness Surveillance Program classifies whether the illness was definitely, probably or possibly related to pesticide exposure. The program’s public query tool, CalPIQ, can filter cases by application site, including structural pest control.
The same department’s pesticide use reports count every structural pest control application. Setting the illness cases against the applications that produced them gives a rate, which neither record provides on its own. We retrieved every structural pest control case identified from 2016 to 2023 and matched them to the application counts in our eight-year analysis of structural pesticide use.
One treatment accounts for almost all of it
| Treatment | Applications, 2016 to 2023 | Illness cases | Cases per 100,000 applications |
|---|---|---|---|
| Sulfuryl fluoride fumigation | 762,936 | 116 | 15.2 |
| All other structural treatments | 127,756,639 | 19 | 0.015 |
| All structural pest control | 128,519,575 | 135 | 0.105 |
Sources: California Department of Pesticide Regulation, Pesticide Illness Surveillance Program, CalPIQ detail query, application site Structural Pest Control, case years 2016 to 2023, retrieved 3 October 2026; Pesticide Use Reports 2016 to 2023, site code 10, application counts. Author calculation.
What it means. Per application, a fumigation was about 1,000 times more likely than any other structural treatment to be followed by a reported illness. Put the other way, roughly one fumigation in 6,600 produced a reported case, against one in 6.7 million of all other structural applications. Everything else professional pest control does in California, about 16 million applications a year of sprays, baits and gels, produced 19 reported cases in eight years.
What limits it. Illness surveillance depends on someone reporting the illness, and mild cases go unreported, so these are minimum counts. A case is one person; a family exposed together counts as several cases. Most cases, 98 of 135, are classified only as possibly related to pesticide exposure. For context, the program recorded 8,446 cases across all settings in the same years, so structural pest control was 1.6 percent of the total.
Year by year
What it means. Fumigation cases ran between 13 and 26 a year, except in 2020 and 2021, when they fell to 3 each while fumigations stayed above 90,000 a year. The data do not say why. Reduced reporting during the pandemic is one possible explanation; we have not verified it.
What limits it. Cases are counted by the year they were identified, which can differ from the year of exposure.
How people were exposed
Occupants after re-entry, 72 cases. The largest group is residents or workers who became ill after returning to a building that had been fumigated and, in most narratives, cleared for re-entry. Reported symptoms are typically headache, nausea, eye and throat irritation and breathing discomfort. In one 2016 case the county found the operator had injected slightly more fumigant than the label allowed.
Entry under the tarps, 21 cases. People who went inside buildings while they were under fumigation: break-ins, a person retrieving belongings, neighbours rescuing a cat trapped in a tented sub-area. In the cat case the operator was cited for not checking sub-areas for pets before fumigating.
Gas moving off the structure, 12 cases. Neighbours, security guards and passers-by exposed to fumigant escaping a tented building.
Workers on a re-entry day, 6 cases. All from one 2023 episode at a fumigated medical building, where staff cleaning on the day of re-entry developed symptoms.
What limits it. We grouped cases from the program’s activity and exposure-type fields and checked the groupings against the case narratives. Three cases had unknown or other circumstances.
Six deaths, five of them inside buildings under fumigation
Six of the 116 fumigation cases were fatal: one each in 2016, 2016, 2018, 2020, 2021 and 2022. Five involved people who were inside a building while it was under fumigation. The sixth was a woman found ill in the courtyard of an apartment building fumigated the day before, who had spent an unknown time inside; the record does not say whether the building had been cleared. The five include a man who broke into an apartment building 18 hours into a fumigation and died on the way to hospital; a man who stayed near his tented house and was found inside it; an unidentified man found under a tarp after entering through a window; and a man found in a fumigated hotel, where the coroner attributed his death to the combined effects of methamphetamine, sulfuryl fluoride and the chloropicrin warning agent, with asthma contributing.
What it means. No death in eight years is recorded as an occupant who re-entered after clearance, or a neighbour. The fatal risk on this record is to people who get inside a structure while it is full of gas. In the 2016 apartment case, the operator was cited for fumigating without chloropicrin, the eye-irritant warning agent added to deter entry, because a security guard was posted.
What limits it. Six deaths is a small number and cannot support a trend. Narratives are summaries by investigators; coroner reports were not available for every case.
The 19 cases from everything else
The non-fumigation cases are a mix. Seven involved heat treatment for termites, six of them from a single 2017 episode in which a heat treatment was run in an office building while employees kept working; the program records heat treatment as a “device”. Six involved a copper naphthenate wood preservative, including an episode in which the investigator found the person applying it was a day labourer not trained to apply pesticides. Five involved fipronil or a pyrethroid termite treatment, and one an unknown product.
What it means. Outside fumigation, reported harm from professional structural pest control in California is rare enough to be counted one case at a time.
Checks on the numbers
1. Complete case retrieval
Method. One CalPIQ detail query for application site Structural Pest Control, both agricultural and non-agricultural use, case years 2016 to 2023.
Result. 135 cases, matching the total the tool reports, with no duplicate case numbers within a year.
2. Matching denominators
Method. Fumigations are the reported application counts for sulfuryl fluoride, chemical code 618, at site code 10; all other applications are the remainder of the site code 10 total.
Result. 762,936 fumigations and 127,756,639 other applications over the eight years.
Limitations. The illness program and the use reports classify site independently; a case recorded under structural pest control does not always involve a licensed structural business, as the untrained-applicator cases show.
3. Fatality verification
Method. Read every narrative containing a death-related term.
Result. Six fatal cases, all sulfuryl fluoride, all classified definite or probable.
Related: consumer foggers used at home were linked to more reported illness than all professional pest control; see bug bombs and illness in California.
Related research: pesticide illness cases at California schools; US poison center insecticide exposures.
Download the data
The tables in this report are published as CSV files under a Creative Commons Attribution 4.0 licence. You may republish, remix and build on them, including commercially, with attribution to The Pest Control Brief and a link to this page.
- All 135 structural pest control illness cases, 2016 to 2023, with circumstances and the program’s narratives (CSV, 135 rows)
- Cases and applications by year, fumigation and all other treatments (CSV, 8 rows)
How to cite this report
The Pest Control Brief, “Who Gets Hurt by Pest Control? Eight Years of California Illness Reports, Matched to 128 Million Applications”, 2 October 2026. https://thepestcontrolbrief.com/pest-control-pesticide-illness-data/
References
- California Department of Pesticide Regulation, Pesticide Illness Surveillance Program. California Pesticide Illness Query (CalPIQ). apps.cdpr.ca.gov/calpiq. Detail query, application site Structural Pest Control, 2016 to 2023, retrieved 3 October 2026. Also queried for all settings (8,446 cases) and household sites (890 cases) for context.
- California Department of Pesticide Regulation. Pesticide Use Report annual archives, 2016 to 2023. files.cdpr.ca.gov/pub/outgoing/pur_archives/. Accessed 2 October 2026.
- The Pest Control Brief. Where California tents its houses. thepestcontrolbrief.com/california-fumigation-by-county.
How the match was made
Cases. CalPIQ returns cases DPR scientists classified as definitely, probably or possibly related to pesticide exposure, with year identified, county, relationship, activity, exposure type, pesticide and narrative. We retrieved all cases with application site Structural Pest Control for 2016 to 2023.
Applications. Summed from the application count field of every site code 10 Pesticide Use Report record in the same years.
Rates. Cases divided by applications, per 100,000. A case naming sulfuryl fluoride is counted as a fumigation case.
What we did not do. We did not contact the program for unpublished data, did not attempt to estimate under-reporting, and do not identify any individual. The narratives in the CSV are as published by the department.
Limitations. Reported cases only. Possible, probable and definite cases are combined. California only.
Last reviewed: 3 October 2026.
For health and consumer reporters
Most quotable statistics
- Of 135 pesticide illness cases linked to structural pest control in California from 2016 to 2023, 116 involved sulfuryl fluoride fumigation.
- That is 15.2 reported cases per 100,000 fumigations, against 0.015 per 100,000 for all other structural treatments.
- About 128 million other structural pest control applications in eight years produced 19 reported illness cases.
- Six people died; five had entered buildings while they were under fumigation.
- 72 fumigation cases were people who became ill after returning to their building.
Caveats that travel with them
Reported cases are minimum counts. Most are classified as possibly, not definitely, related. A case is a person, not an incident.
Press summary
Nearly all reported illnesses from professional pest control in California come from one treatment, whole-building fumigation, according to an analysis by The Pest Control Brief that matches state illness surveillance records to state pesticide use reports. Of 135 illness cases linked to structural pest control from 2016 to 2023, 116 involved sulfuryl fluoride, a fumigant used in 0.6 percent of applications, giving 15.2 cases per 100,000 fumigations against 0.015 for all other treatments. Six people died, five of whom had entered buildings while they were being fumigated. Most other cases were occupants who felt ill after returning home.
Headlines editors could use
- Tenting is behind 86 percent of pest control illness reports in California
- 128 million pest treatments, 19 illness reports: the risk is in the tent
- Six deaths in eight years, most after people got inside tented buildings
- Is pest control safe? What eight years of California illness data show
What people ask
Is professional pest control safe?
Outside fumigation, reported illness is very rare: 19 cases in about 128 million California structural applications over eight years, or 0.015 per 100,000. Reported cases are minimum counts.
Is termite tenting dangerous?
It carries much higher reported risk per treatment than other pest control: 15.2 illness cases per 100,000 fumigations in California from 2016 to 2023. Most cases were mild symptoms after re-entry; five of the six deaths involved people inside the building during fumigation.
Can you get sick going back into a house after fumigation?
Some people report symptoms. 72 California cases from 2016 to 2023 were occupants who became ill after returning to a fumigated building, most of them classified as possibly related.
Has anyone died from termite fumigation in California?
The state’s illness program recorded six deaths linked to sulfuryl fluoride from 2016 to 2023. Five involved people inside a building while it was under fumigation, including break-ins; in the sixth, whether the building had been cleared is not recorded.
What is chloropicrin in fumigation?
A warning agent added to make the tented building intolerable to enter. In one fatal 2016 case the operator was cited for fumigating without it.
Is heat treatment safer than fumigation?
These data cannot compare them, because heat treatments are not counted as applications in the use reports. The illness program did record one 2017 heat-treatment episode with six cases.
Where do the figures come from?
From the California Department of Pesticide Regulation’s Pesticide Illness Surveillance Program and its Pesticide Use Reports. All 135 cases are in the CSV above.
