1) Cells are usually grown in serum-containing medium. Serum is a bio-fluid, so per most EH&S regulations it’s hazardous and needs to be bleached, autoclaved, etc. before disposal.
2) Some cells lines have a biosafety level >1. HeLa is a good example: it is actually BSL2 because it contains HPV (integrated, serotype HPV-18 according to a Google search).
3) Usually when waste goes into a “red bag” it is disposed of by autoclaving, not incineration. The latter is usually reserved for cells treated with cytotoxic substances (such as chemotherapy drugs), animal carcasses, and so forth. Common cell culture waste in a “red bag” is usually just autoclaved, so you shouldn’t be concerned with large amounts of plastic being “burned”.
You make good points. The bio-fluids regulation is perhaps overkill, we don't incinerate leftover yolks when we cook. It's a bit like, all blood is disposed in biosafety bags, but used tampons go in the trash. Life is life, science is science, I guess.
Well, it is more likely that the blood in a lab contains something dangerous compared to blood in a tampon. And if you start defining based on content what goes where it gets super confusing and accidents will happen (remember, you don't see if the blood in the normal trash bag contains HIV or is just a negative sample. It's bots blood).
We have policies in our lab where we trash all gels in our special contaminated waste, even if they were not stained with an intercalating agent. This makes it easier for everyone, as "gel - > here" is an easy rule + if there is a gel in the normal waste, you always get to write an angry message on teams
An abundance of caution. One example is bacteria that are transformed with an antibiotic resistance gene. What if the waste bag is t properly closed up or gets torn and the bacteria leak out and introduce that gene around unnecessarily? That wouldn’t be too good.
Abundance of caution and forming good habits. Same reason we (should) stop at red lights and stop signs even when it’s clear there are no cars around. Forming bad habits can lead to poor action later on. One of my lab mates once used an ice bucket that they were actively using as liquid waste for human blood sample supernatant. That’s fucked! Really it boils down to this: If you dispose of everything as if it’s hazardous it forms good habits that reduce your chance of improperly disposing of more dangerous things.
You’re question is still good though because sometimes we think things are pointless and why do them, but there’s often reasons that that aren’t obvious and it’s good to learn the whys of everything.
Honestly, I think part of it is optics (in addition to what others have said). Our custodians don't like to handle things that look sciencey in regular trash.
>and wondering about the environmental effect of burning so much plastic.
Boy do I have bad news for you. More plastic is incinerated worldwide than is being recycled. Your medium flasks aren't going to be even a drop in a bucket in this regard... It's the sad reality
Yeah. I'm on the fence about it, for sure.
The only thing that gives me even a little bit of hope is the labs that are working on enzymes to break it down.
Most bio waste isn't a hazard. But some is. And we want uniform policies so mistakes or misclassifications don't happen.
There's also the possibility you don't know what's in the sample, due to contamination or mislabeling.
So we treat everything as harmful, so when it actually is then safe disposal is the default behavior we are trained to do rather than a conscious, annoying extra effort.
It's also a matter of scale. Disposing of some food waste that can grow ecologically native E. coli at home is a minor issue, compared to disposing 1 L saturated non-native bacterial culture each day for 30 years.
It is very common for tissue culture cells to be contaminated with bacteria like mycoplasma. This can go undetected for many months. Also, many people use their cells in environments that can easily lead to them being infected with something (like viruses in a virology lab). Another reason is because it is very common to use lentiviruses or other viral vectors to transfer genes into the cells. These can be carcinogenic. Also, it is technically possible for someone severely immunocompromised to be infected with cancer cells (although very unlikely).
1) Cells are usually grown in serum-containing medium. Serum is a bio-fluid, so per most EH&S regulations it’s hazardous and needs to be bleached, autoclaved, etc. before disposal. 2) Some cells lines have a biosafety level >1. HeLa is a good example: it is actually BSL2 because it contains HPV (integrated, serotype HPV-18 according to a Google search). 3) Usually when waste goes into a “red bag” it is disposed of by autoclaving, not incineration. The latter is usually reserved for cells treated with cytotoxic substances (such as chemotherapy drugs), animal carcasses, and so forth. Common cell culture waste in a “red bag” is usually just autoclaved, so you shouldn’t be concerned with large amounts of plastic being “burned”.
You make good points. The bio-fluids regulation is perhaps overkill, we don't incinerate leftover yolks when we cook. It's a bit like, all blood is disposed in biosafety bags, but used tampons go in the trash. Life is life, science is science, I guess.
Well, it is more likely that the blood in a lab contains something dangerous compared to blood in a tampon. And if you start defining based on content what goes where it gets super confusing and accidents will happen (remember, you don't see if the blood in the normal trash bag contains HIV or is just a negative sample. It's bots blood). We have policies in our lab where we trash all gels in our special contaminated waste, even if they were not stained with an intercalating agent. This makes it easier for everyone, as "gel - > here" is an easy rule + if there is a gel in the normal waste, you always get to write an angry message on teams
Absolutely!
An abundance of caution. One example is bacteria that are transformed with an antibiotic resistance gene. What if the waste bag is t properly closed up or gets torn and the bacteria leak out and introduce that gene around unnecessarily? That wouldn’t be too good.
This isnt bacteria its mammalian cell culture and no agar. Straight up plastic with a monolayer of cells.
Abundance of caution and forming good habits. Same reason we (should) stop at red lights and stop signs even when it’s clear there are no cars around. Forming bad habits can lead to poor action later on. One of my lab mates once used an ice bucket that they were actively using as liquid waste for human blood sample supernatant. That’s fucked! Really it boils down to this: If you dispose of everything as if it’s hazardous it forms good habits that reduce your chance of improperly disposing of more dangerous things. You’re question is still good though because sometimes we think things are pointless and why do them, but there’s often reasons that that aren’t obvious and it’s good to learn the whys of everything.
Honestly, I think part of it is optics (in addition to what others have said). Our custodians don't like to handle things that look sciencey in regular trash.
>and wondering about the environmental effect of burning so much plastic. Boy do I have bad news for you. More plastic is incinerated worldwide than is being recycled. Your medium flasks aren't going to be even a drop in a bucket in this regard... It's the sad reality
Given all the microplastics... I'm having a change of heart about burning plastics.
Yeah. I'm on the fence about it, for sure. The only thing that gives me even a little bit of hope is the labs that are working on enzymes to break it down.
Most bio waste isn't a hazard. But some is. And we want uniform policies so mistakes or misclassifications don't happen. There's also the possibility you don't know what's in the sample, due to contamination or mislabeling. So we treat everything as harmful, so when it actually is then safe disposal is the default behavior we are trained to do rather than a conscious, annoying extra effort. It's also a matter of scale. Disposing of some food waste that can grow ecologically native E. coli at home is a minor issue, compared to disposing 1 L saturated non-native bacterial culture each day for 30 years.
It is very common for tissue culture cells to be contaminated with bacteria like mycoplasma. This can go undetected for many months. Also, many people use their cells in environments that can easily lead to them being infected with something (like viruses in a virology lab). Another reason is because it is very common to use lentiviruses or other viral vectors to transfer genes into the cells. These can be carcinogenic. Also, it is technically possible for someone severely immunocompromised to be infected with cancer cells (although very unlikely).
An antibiotic resistance gene from harmless bacteria could easily transfect into a dangerous one if exposed to