# How protective is a surgical mask? **URL:** \ **Category:** Factual Questions\ **Created:** [April 1, 2003, 7:43pm UTC](https://boards.straightdope.com/t/how-protective-is-a-surgical-mask/165773 "2003-04-01T19:43:59Z")\ **Posts on this page:** 17\ **Page:** 1
**Author:** ![bare](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bare/32/471_2.png) [@bare](https://boards.straightdope.com/u/bare)\ **Post date:** [April 1, 2003, 7:43pm UTC](https://boards.straightdope.com/t/how-protective-is-a-surgical-mask/165773/1 "2003-04-01T19:43:59Z")
Any news photo the last few days shows everyone wearing surgical masks as protection against virus and germs. Are the really effective for this use? Will a semi-clean hankie give some measure of protection? ---
**Author:** ![Nametag](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/nametag/32/406_2.png) [@Nametag](https://boards.straightdope.com/u/Nametag)\ **Post date:** [April 1, 2003, 7:52pm UTC](https://boards.straightdope.com/t/how-protective-is-a-surgical-mask/165773/2 "2003-04-01T19:52:59Z")
It’s a joke. Surgical masks are designed to protect surgical _patients_ from incidental release of microbe-laden droplets by _surgeons_. Such droplets are likely to be the vector of a flu or common cold, if you’re standing really, really, close. There are other likely ways to get infected, and which is most likely depends on the disease. ---
**Author:** ![Ferret\_Herder](https://avatars.discourse-cdn.com/v4/letter/f/e47774/32.png) [@Ferret\_Herder](https://boards.straightdope.com/u/Ferret_Herder)\ **Post date:** [April 1, 2003, 8:35pm UTC](https://boards.straightdope.com/t/how-protective-is-a-surgical-mask/165773/3 "2003-04-01T20:35:42Z")
I should note that during surgery, the mask helps keep the surgeon from accidentally ingesting/inhaling any blood droplets that might spray onto his or her face. Similar masks are required in many hospitals by patients infected with various droplet-transmitted illnesses (like tuberculosis) when they are in certain areas, mostly outside their rooms. This is to help prevent them from transmitting their illness to others. Otherwise, **Nametag** is correct. From what I’ve read, SARS seems to be a droplet-spread illness, and if that’s the case, careful hand-washing plus being careful about what you allow to touch your face, what you put in your mouth, etc., ought to be your best defense. ---
**Author:** ![KarlGauss](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/karlgauss/32/3713_2.png) [@KarlGauss](https://boards.straightdope.com/u/KarlGauss)\ **Post date:** [April 1, 2003, 9:56pm UTC](https://boards.straightdope.com/t/how-protective-is-a-surgical-mask/165773/4 "2003-04-01T21:56:07Z")
It may depend on the type of mask. If you’re wearing one similar or identical to N95, which stops most particles \> 0.3 microns, you are probably protected from the current SARS virus. Certainly, there are no documented cases of transmission in people who wore that type of mask (and took other precautions like handwashing/gloves). The standard surgical masks offer no protection. ---
**Author:** ![bare](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bare/32/471_2.png) [@bare](https://boards.straightdope.com/u/bare)\ **Post date:** [April 1, 2003, 10:18pm UTC](https://boards.straightdope.com/t/how-protective-is-a-surgical-mask/165773/5 "2003-04-01T22:18:09Z")
Interesting dilema. 3M, manufacturer of N95 masks is out of stock until mid-April. Hope that pesky SARS takes its time getting around. ---
**Author:** ![bare](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bare/32/471_2.png) [@bare](https://boards.straightdope.com/u/bare)\ **Post date:** [April 1, 2003, 10:20pm UTC](https://boards.straightdope.com/t/how-protective-is-a-surgical-mask/165773/6 "2003-04-01T22:20:04Z")
Interesting dilemma. 3M, manufacturer of N95 masks is out of stock until mid-April. Hope that pesky SARS takes its time getting around. ---
**Author:** ![MaryEFoo](https://avatars.discourse-cdn.com/v4/letter/m/ba8739/32.png) [@MaryEFoo](https://boards.straightdope.com/u/MaryEFoo)\ **Post date:** [April 1, 2003, 11:17pm UTC](https://boards.straightdope.com/t/how-protective-is-a-surgical-mask/165773/7 "2003-04-01T23:17:58Z")
Proposition: It takes a particular standard of mask that you wear to protect you from catching SARS from others, but with a lesser standard, it prevents you from **giving** it to others, ie it stops you spraying droplets. So the bigger % of people in the population who wear masks, the less the spread of the disease. PS, wash your hands a lot. ---
**Author:** ![ftg](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ftg/32/2801_2.png) [@ftg](https://boards.straightdope.com/u/ftg)\ **Post date:** [April 2, 2003, 6:27pm UTC](https://boards.straightdope.com/t/how-protective-is-a-surgical-mask/165773/8 "2003-04-02T18:27:34Z")
To say that surgical masks offer no protection is carrying things a bit far. They certainly aren’t 100% effective but that doesn’t make them 100% useless. If it stops 95% of the bug carrying droplets from getting inside you, that will help. And a good mask is probably a lot more effective than that _if worn properly_. The real wildcard in SARS is that we don’t know yet if it survives dried up or requires water droplets to float around on. Water droplets are stopped somewhat by better quality masks. Dried viruses are much harder to stop. ---
**Author:** ![istara](https://avatars.discourse-cdn.com/v4/letter/i/e79b87/32.png) [@istara](https://boards.straightdope.com/u/istara)\ **Post date:** [April 2, 2003, 7:15pm UTC](https://boards.straightdope.com/t/how-protective-is-a-surgical-mask/165773/9 "2003-04-02T19:15:04Z")
I think they’re starting to become a fashion statement. We had pics from Reuters today with some Chinese woman with a really cool colourful design on her mask. ---
**Author:** ![Rabid\_Squirrel](https://avatars.discourse-cdn.com/v4/letter/r/e0b2c6/32.png) [@Rabid\_Squirrel](https://boards.straightdope.com/u/Rabid_Squirrel)\ **Post date:** [April 2, 2003, 9:18pm UTC](https://boards.straightdope.com/t/how-protective-is-a-surgical-mask/165773/10 "2003-04-02T21:18:04Z")
Again, it’s a question of culture. I’ve heard in Japan, it’s polite to wear a mask if you have a cold. ---
**Author:** ![Speaker\_for\_the\_Dead](https://avatars.discourse-cdn.com/v4/letter/s/c77e96/32.png) [@Speaker\_for\_the\_Dead](https://boards.straightdope.com/u/Speaker_for_the_Dead)\ **Post date:** [April 2, 2003, 11:24pm UTC](https://boards.straightdope.com/t/how-protective-is-a-surgical-mask/165773/11 "2003-04-02T23:24:45Z")
Here’s the response from a good course: > [@](#): > > With respect to precautions for Canadians travelling to Toronto, or > using Toronto airport in transit, I heard an interview this morning on > CBC radio with the provincial Medical Officer of Health. The interviewer > asked the pertinent question, “Should travellers to or through Toronto > take any special precautions, including wearing masks?” > The response was very clear. The infection is spread by droplet > transmission, not by airborne spread. This means that masks are > unnecessary. Close contacts of cases or suspect cases should use > appropriate precautions, including scrupulous hand washing. > The MOH specifically stated “Travellers to Toronto do not need to wear > masks, either at the airport, or when walking about downtown Toronto.” I will contact both of you immediately if we (physicians) receive any > instructions that would change the advice that has been given. Best regards, Anne Doig ---
**Author:** ![Speaker\_for\_the\_Dead](https://avatars.discourse-cdn.com/v4/letter/s/c77e96/32.png) [@Speaker\_for\_the\_Dead](https://boards.straightdope.com/u/Speaker_for_the_Dead)\ **Post date:** [April 2, 2003, 11:26pm UTC](https://boards.straightdope.com/t/how-protective-is-a-surgical-mask/165773/12 "2003-04-02T23:26:18Z")
That’s purely on the protection from SARS, of course. ---
**Author:** ![Cerowyn](https://avatars.discourse-cdn.com/v4/letter/c/82dd89/32.png) [@Cerowyn](https://boards.straightdope.com/u/Cerowyn)\ **Post date:** [April 2, 2003, 11:30pm UTC](https://boards.straightdope.com/t/how-protective-is-a-surgical-mask/165773/13 "2003-04-02T23:30:17Z")
> [@](#): > > \*Originally posted by Rabid\_Squirrel \* > \*\*I’ve heard in Japan, it’s polite to wear a mask if you have a cold. \*\* Yes, that’s true. Many people also wear masks during spring to ward against pollen. ---
**Author:** ![bare](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bare/32/471_2.png) [@bare](https://boards.straightdope.com/u/bare)\ **Post date:** [April 2, 2003, 11:37pm UTC](https://boards.straightdope.com/t/how-protective-is-a-surgical-mask/165773/14 "2003-04-02T23:37:59Z")
Regarding Doig’s quote, we keep hearing that scientists don’t even know if they are dealing with a germ or a virus, nor are they certain of the method of transmission for certain. ---
**Author:** ![China\_Guy](https://avatars.discourse-cdn.com/v4/letter/c/779978/32.png) [@China\_Guy](https://boards.straightdope.com/u/China_Guy)\ **Post date:** [April 3, 2003, 7:00am UTC](https://boards.straightdope.com/t/how-protective-is-a-surgical-mask/165773/15 "2003-04-03T07:00:56Z")
Need to move this over to IMHO. Now I am not a doctor nor do I play one on TV, I do however live in a high risk area. From the [Center for Disease Control](http://www.cdc.gov/ncidod/sars/factsheet.htm) has these recommendations: If you have SARS and are being cared for at home, you should: Follow the instructions given by your health care provider. Limit your activities outside the home during this 10-day period. For example, do not go to work, school, or public areas. Wash your hands often and well, especially after you have blown your nose. Cover your mouth and nose with tissue when you sneeze or cough. If possible, wear a surgical mask when around other people in your home. If you can’t wear a mask, the members of your household should wear one when they are around you. Don’t share silverware, towels, or bedding with anyone in your home until these items have been washed with soap and hot water. Clean surfaces (counter or tabletops, door knobs, bathroom fixtures, etc.) that have been contaminated by body fluids (sweat, saliva, mucous, or even vomit or urine) from the SARS patient with a household disinfectant used according to the manufacturer’s instructions. Wear disposable gloves during all cleaning activities. Throw these out when you are done. Do not reuse them. Follow these instructions for 10 days after your fever and respiratory symptoms have gone away. If you are caring for someone at home who has SARS, you should: Be sure that the person with SARS has seen a health care provider and is following instructions for medication and care. Be sure that all members of your household are washing their hands frequently with soap and hot water or using alcohol-based hand wash. Wear disposable gloves if you have direct contact with body fluids of a SARS patient. However, the wearing of gloves is not a substitute for good hand hygiene. After contact with body fluids of a SARS patient, remove the gloves, throw them out, and wash your hands. Do not wash or reuse the gloves. Encourage the person with SARS to cover their mouth and nose with a tissue when coughing or sneezing. If possible, the person with SARS should wear a surgical mask during close contact with other people in the home. If the person with SARS cannot wear a surgical mask, other members of the household should wear one when in the room with that person. Do not use silverware, towels, bedding, clothing, or other items that have been used by the person with SARS until these items have been washed with soap and hot water. Clean surfaces (counter or tabletops, door knobs, bathroom fixtures, etc.) that have been contaminated by body fluids (sweat, saliva, mucous, or even vomit or urine) with a household disinfectant used according to the manufacturer’s instructions. Wear disposable gloves during all cleaning activities. Throw these out when done. Do not reuse them. Follow these instructions for 10 days after the sick person’s fever and respiratory symptoms have gone away. If you develop a fever or respiratory symptoms, contact your health care provider immediately and tell him or her that you have had close contact with a SARS patient. ---
**Author:** ![Alcibiades](https://avatars.discourse-cdn.com/v4/letter/a/cab0a1/32.png) [@Alcibiades](https://boards.straightdope.com/u/Alcibiades)\ **Post date:** [April 3, 2003, 3:24pm UTC](https://boards.straightdope.com/t/how-protective-is-a-surgical-mask/165773/16 "2003-04-03T15:24:13Z")
I was advised today that surgical masks have a use life of 30 minutes. Certainly some of the soggy gooey masks I have seen on Pedder Street in HK indicate that is correct. ---
**Author:** ![Dogface](https://avatars.discourse-cdn.com/v4/letter/d/9d8465/32.png) [@Dogface](https://boards.straightdope.com/u/Dogface)\ **Post date:** [April 4, 2003, 3:27am UTC](https://boards.straightdope.com/t/how-protective-is-a-surgical-mask/165773/17 "2003-04-04T03:27:39Z")
In the laboratory, I have worn surgical masks purely as a form of dust/droplet protection, and that purely short-term. The fiber mesh is sufficient to stop me from contaminating a sample, but not for long. The major use they have is to keep me aware that I am working with an inhalation hazard and act accordingly. They are not considered to be a substitute for a full-fledged airborne hazard hood (a large piece of equipment that’s installed and inspected regularly).