# Emergency trunk release handles, how much light exposure needed? **URL:** \ **Category:** Factual Questions\ **Created:** [June 29, 2018, 2:57pm UTC](https://boards.straightdope.com/t/emergency-trunk-release-handles-how-much-light-exposure-needed/816991 "2018-06-29T14:57:25Z")\ **Posts on this page:** 8\ **Page:** 1
**Author:** ![Dingbang](https://avatars.discourse-cdn.com/v4/letter/d/ac8455/32.png) [@Dingbang](https://boards.straightdope.com/u/Dingbang)\ **Post date:** [June 29, 2018, 2:57pm UTC](https://boards.straightdope.com/t/emergency-trunk-release-handles-how-much-light-exposure-needed/816991/1 "2018-06-29T14:57:25Z")
New and recent cars in the U.S. have a glow-in-the-dark emergency handle to release the trunk lid, but how much light exposure do they need to glow? My Googling only confirms that they glow after exposure to light, but as a practical matter wouldn’t there be times when there is minimal or no light exposure? If you stuff your victim in the trunk quickly during daytime, or at night with no lights around, how does the handle get enough exposure to work? I’m not questioning the value of the emergency device itself. Perhaps the answer is that it won’t always glow but it still works if you fumble around and find it, so it’s still valuable. But I’m curious if they’re made of something super sensitive to light exposure, more than the average glow-in-the dark item. ---
**Author:** ![beowulff](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/beowulff/32/542_2.png) [@beowulff](https://boards.straightdope.com/u/beowulff)\ **Post date:** [June 29, 2018, 3:07pm UTC](https://boards.straightdope.com/t/emergency-trunk-release-handles-how-much-light-exposure-needed/816991/2 "2018-06-29T15:07:27Z")
Cars are usually used outside, where the light is extremely bright. Even a bog-standard glow-in-the-dark paint will still have a visible glow for many hours after a brief exposure to bright light. And, the thing to remember is: the glow doesn’t have to be very bright. If you are in a tomb-black box, even a glow that is barely at the threshold of human perception is enough. I suspect that those handles will be able to emit a glow like that for _days_ after exposure to sunlight. [Here’s a curve I found.](http://www.cospheric.com/resize/images/PHYPMS-decay.jpg?bw=550&w=550&bh=550&h=550) It shows that for this phosphor, the light emitted is almost 10,000x more than the visual threshold after an hour, and is decaying very slowly. ---
**Author:** ![E-DUB](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/e-dub/32/403_2.png) [@E-DUB](https://boards.straightdope.com/u/E-DUB)\ **Post date:** [June 29, 2018, 3:10pm UTC](https://boards.straightdope.com/t/emergency-trunk-release-handles-how-much-light-exposure-needed/816991/3 "2018-06-29T15:10:56Z")
At least the OP didn’t say “need answer fast”. ---
**Author:** ![Dingbang](https://avatars.discourse-cdn.com/v4/letter/d/ac8455/32.png) [@Dingbang](https://boards.straightdope.com/u/Dingbang)\ **Post date:** [June 29, 2018, 5:09pm UTC](https://boards.straightdope.com/t/emergency-trunk-release-handles-how-much-light-exposure-needed/816991/4 "2018-06-29T17:09:41Z")
Ah, that’s helpful. Guess I was thinking more of the cheap glow toys I had as a kid. Thanks for the quick answer. ---
**Author:** ![carnivorousplant](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/carnivorousplant/32/3563_2.png) [@carnivorousplant](https://boards.straightdope.com/u/carnivorousplant)\ **Post date:** [June 29, 2018, 5:21pm UTC](https://boards.straightdope.com/t/emergency-trunk-release-handles-how-much-light-exposure-needed/816991/5 "2018-06-29T17:21:54Z")
> [@Dingbang](#): > > If you stuff your victim in the trunk quickly during daytime, or at night with no lights around, how does the handle get enough exposure to work? Paint the damn thing. ---
**Author:** ![beowulff](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/beowulff/32/542_2.png) [@beowulff](https://boards.straightdope.com/u/beowulff)\ **Post date:** [June 29, 2018, 5:52pm UTC](https://boards.straightdope.com/t/emergency-trunk-release-handles-how-much-light-exposure-needed/816991/6 "2018-06-29T17:52:12Z")
And - think about it this way: these handles are really designed to let people out who have managed to lock themselves in the trunk - kids playing, for example. In those cases, they are going to want to get out immediately - seconds after the trunk closes. Cases where someone wakes up after being in the trunk for hours are much rarer, and presumably, if you find yourself in that situation, you will probably find yourself bound and gagged, too… ---
**Author:** ![campp](https://avatars.discourse-cdn.com/v4/letter/c/c5a1d2/32.png) [@campp](https://boards.straightdope.com/u/campp)\ **Post date:** [June 29, 2018, 6:14pm UTC](https://boards.straightdope.com/t/emergency-trunk-release-handles-how-much-light-exposure-needed/816991/7 "2018-06-29T18:14:44Z")
Mount a light near the handle that runs whenever the car does. ---
**Author:** ![KMS94](https://avatars.discourse-cdn.com/v4/letter/k/ad7895/32.png) [@KMS94](https://boards.straightdope.com/u/KMS94)\ **Post date:** [June 29, 2018, 8:13pm UTC](https://boards.straightdope.com/t/emergency-trunk-release-handles-how-much-light-exposure-needed/816991/8 "2018-06-29T20:13:21Z")
> [@beowulff](#): > > And - think about it this way: these handles are really designed to let people out who have managed to lock themselves in the trunk - kids playing, for example. In those cases, they are going to want to get out immediately - seconds after the trunk closes. Cases where someone wakes up after being in the trunk for hours are much rarer, and presumably, if you find yourself in that situation, you will probably find yourself bound and gagged, too… Not to mention, if you are the victim of a planned snatching, the emergency escape handle would likely be removed.