# How long for botulism spores to grow in anaerobic environment **URL:** \ **Category:** Factual Questions\ **Created:** [March 11, 2018, 8:17pm UTC](https://boards.straightdope.com/t/how-long-for-botulism-spores-to-grow-in-anaerobic-environment/810395 "2018-03-11T20:17:51Z")\ **Posts on this page:** 6\ **Page:** 1
**Author:** ![Velocity](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/velocity/32/18006_2.png) [@Velocity](https://boards.straightdope.com/u/Velocity)\ **Post date:** [March 11, 2018, 8:17pm UTC](https://boards.straightdope.com/t/how-long-for-botulism-spores-to-grow-in-anaerobic-environment/810395/1 "2018-03-11T20:17:51Z")
6 hours? 2 days? Etc. ---
**Author:** ![DavidwithanR](https://avatars.discourse-cdn.com/v4/letter/d/3bc359/32.png) [@DavidwithanR](https://boards.straightdope.com/u/DavidwithanR)\ **Post date:** [March 11, 2018, 8:45pm UTC](https://boards.straightdope.com/t/how-long-for-botulism-spores-to-grow-in-anaerobic-environment/810395/2 "2018-03-11T20:45:22Z")
From Wikipedia: - The spores require warm temperatures, a protein source, an anaerobic environment, and moisture in order to become active and produce toxin. It seems that the toxin production is also slowed down a lot by high salt and high acid. For some safety instructions, see [Botulism: Prevention](https://en.m.wikipedia.org/wiki/Botulism#Prevention) on Wikipedia. ---
**Author:** ![DavidwithanR](https://avatars.discourse-cdn.com/v4/letter/d/3bc359/32.png) [@DavidwithanR](https://boards.straightdope.com/u/DavidwithanR)\ **Post date:** [March 11, 2018, 9:06pm UTC](https://boards.straightdope.com/t/how-long-for-botulism-spores-to-grow-in-anaerobic-environment/810395/3 "2018-03-11T21:06:05Z")
Hmmmm. I got carried away and obviously didn’t answer your question. More from Wikipedia: > [@](#): > > In April 1994, the largest outbreak of botulism in the United States since 1978 occurred in El Paso, Texas. Thirty persons were affected; 4 required mechanical ventilation. All ate food from a Greek restaurant. The attack rate among persons who ate a potato-based dip was 86% (19/22) compared with 6% (11/176) among persons who did not eat the dip (relative risk [RR] Å 13.8; 95% confidence interval [CI], 7.6–25.1). The attack rate among persons who ate an eggplant-based dip was 67% (6/9) compared with 13% (24/189) among persons who did not (RR Å 5.2; 95% CI, 2.9–9.5). Botulism toxin type A was detected from patients and in both dips. Toxin formation resulted from holding aluminum foil-wrapped baked potatoes at room temperature, apparently for several days, before they were used in the dips. Food handlers should be informed of the potential hazards caused by holding foil-wrapped potatoes at ambient temperatures after cooking. This proves that a few days is enough. Beyond that, I don’t know. I’d be inclined to say “If in doubt, throw it out”. ---
**Author:** ![Stranger\_On\_A\_Train](https://avatars.discourse-cdn.com/v4/letter/s/13edae/32.png) [@Stranger\_On\_A\_Train](https://boards.straightdope.com/u/Stranger_On_A_Train)\ **Post date:** [March 11, 2018, 9:07pm UTC](https://boards.straightdope.com/t/how-long-for-botulism-spores-to-grow-in-anaerobic-environment/810395/4 "2018-03-11T21:07:21Z")
It depends on a number of factors including available nutrients and the acidity level in the medium. A quick search turns up D M Wong, K E Young-Perkins, and R L Merson, [“Factors influencing Clostridium botulinum spore germination, outgrowth, and toxin formation in acidified media.”](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC202677/), _Applied and Environmental Microbiology_, June 1988. Stranger ---
**Author:** ![mixdenny](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mixdenny/32/2962_2.png) [@mixdenny](https://boards.straightdope.com/u/mixdenny)\ **Post date:** [March 12, 2018, 9:17pm UTC](https://boards.straightdope.com/t/how-long-for-botulism-spores-to-grow-in-anaerobic-environment/810395/5 "2018-03-12T21:17:20Z")
It took a couple of days for spores to kill animals on Guinard island, it stayed lethal for decades. > **[Gruinard Island](https://en.wikipedia.org/wiki/Gruinard_Island)** > > Gruinard Island (/ˈɡrɪnjərd/ GRIN-yərd; > Scottish Gaelic: Eilean Ghruinneard) is a small, oval-shaped Scottish island approximately 2 kilometres (1+1⁄4 miles) long by 1 km (5⁄8 mi) wide, located in Gruinard Bay, about halfway between Gairloch and Ullapool. At its closest point to the mainland, it is about 1 km (5⁄8 mi) offshore. In 1942, The island became a sacrifice zone, and was dangerous for all mammals after military experiments with the anthrax bacterium, until it was decontaminated The i... Dennis ---
**Author:** ![Stranger\_On\_A\_Train](https://avatars.discourse-cdn.com/v4/letter/s/13edae/32.png) [@Stranger\_On\_A\_Train](https://boards.straightdope.com/u/Stranger_On_A_Train)\ **Post date:** [March 12, 2018, 11:28pm UTC](https://boards.straightdope.com/t/how-long-for-botulism-spores-to-grow-in-anaerobic-environment/810395/6 "2018-03-12T23:28:50Z")
> [@mixdenny](#): > > It took a couple of days for spores to kill animals on Guinard island, it stayed lethal for decades. > > [Gruinard Island - Wikipedia](https://en.wikipedia.org/wiki/Gruinard_Island) That is anthrax, a disease caused by the _Bacillus anthracis_ bacterium which happily thrives in aerobic conditions. Stranger