Having sexual relations where the risk of infection and/or transmission of disease is dramatically reduced by various procedures or actions.
The use of barriers and other devices, to insure there is minimal, if any, transference of bodily fluid between sexual partners, including blood, semen, urine.
In addition it is about preventing access to disease, viruses, that do not require fluid to fluid contact, in order to be spread.
Sex by Yourself is considered to be about as safe as possible, as long as there isn't any involvement with other person's bodily fluids. So a group jerk off is fun and fine, but no splashing each other.
Self Bondage and Autoerotic Asphyxia while are 'sex by yourself' they become a higher risk, mainly due to there not being anyone else present to intervene, should something go terribly wrong.
The goal / purpose of safer sex is to place barriers to reduce the risk of infection. While there are many such barriers, they are not 100% safe, other than simply self masturbation. Even using a dildo without protection, can risk infection, if the dildo has been shared, or not properly sterilized after each use.
This is also about Risk Management. One has to determine what risk they are willing to accept, prior to engaging in any sexual activity with another person.
Use of condoms, dental dams, proper hygiene, sterilization of toys, and the right lubricant for the right device, can help reduce serious risks, to more acceptable levels.
THEY CANNOT ELIMINATE THE RISKS.
The sharing of bodily fluids, such as semen, urine, are high risk. To ejaculate in another's mouth, that might have open sores, is a high risk, hence the use of a Dental Dam can help minimize that particular risk. Just as a condom can when engaging in penetrative sex.
The purpose of any barrier, is to insure it is properly in place, otherwise its effectiveness can be seriously compromised.
Latex condoms can also be a problem, if one has an allergy associated with Latex. There are other types, but the effectiveness is not as well documented as it is with Latex Condoms.
OIL BASED LUBRICANTS WITH LATEX BARRIERS IS NOT RECOMMENDED.
Use of gloves, the latex or other thin surgical type gloves, can also be worn, in order to further prevent infection. There can be fine cuts or skin ruptures that could be a source of transmission or reception of STD's, or other diseases.
Polyurethane is considered a good product for condoms, gloves, as viruses and such cannot easily pass through this material, though there is still not sufficient studies to verify the claims. It's advantage is that it can be used with both water and oil based lubricants.
Practice (Associated Acts): Many sexually transmitted diseases are treatable, and curable. However if left untreated, undetected, they can prove deadly. <u>Regular screening, testing</u> is required no matter what safe sex practices are employed.
Polyfidelity and Monogamy are also considered safer sex. This is where either a 'trusted group' or 'person' become the only acceptable sexual partners.
Use of drugs or alcohol prior to, an during, engaging in sexual activities can be risky, as it will lower one's inhibitions, make one accept or engage in, what they would normally never consider engaging in, if sober.
Plus it can have a lowering of effectiveness on the immune system itself. This would aid in transmission, if contact was made, while be less likely without the lowered levels.
Noteworthy: The concept of pulling out before ejaculation will prevent the transfer of disease is a mis-conception. There is pre ejaculation fluid that is secreted, which can just as dangerous, so pulling out early will not reduce the risk of HIV transmission, STD, transmission, nor does it prevent being impregnated, in the case of straight couples.
Spermacide Nonoxynol 9 was believed to kill off most infectious bacteria, though a recent study by the World Health Organization makes note that this chemical can cause tears in the mucous membrane, increasing the risk rather than reduce it. In addition, there can be an allergic reaction or irritant to it.
Condoms that are pre lubricated with this, should not be used.
Abstinence is the one supposed guaranteed method of avoiding infection. To be truly effective, one first has to be free of any disease, and should be regularly checked, as many diseases, such as HIV, can remain dormant for many years.