Changes

====Sulfur dioxide====

====Sulfur dioxide====

Sulfur, which when burned gives off sulfur dioxide gas, is the oldest known insecticide, when brimstone was used as a fumigant up to 3,000 years ago. It was used in the past against mildew and to sanitize houses quarantined due to infectious diseases such as [[smallpox]] and to kill household insects.<ref>The Environment and Encyclopedia Directory, 2001, Third Edition, p. 135</ref> Clinical and anecdotal reports testify of the past use of  fumigation with sulfur dioxide (such as through the use of sulfur candles) showing that it was highly effective against bedbugs.<ref>http://thebedbugresource.com/phpBB2/viewtopic.php?t=623</ref> In the late 1930 to the mid 1940s it was used in the United Kingdom to fumigate entire homes, and it is reported to have helped reduce infestations by up to 80% in one town under study.<ref>Busvine J.R. 1964. Medical Entomology in Britain. Ann. of App. Biol. 53: 190-199</ref> One recommendation was the use of 20 fluid ounces of liquefied sulfur dioxide to 1200 cubic inches with a repeat treatment within two weeks.<ref> [http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2369743/pdf/brmedj07360-0033b.pdf British Medical Journal], p. 885, Nov. 11. 1933</ref>

Sulfur, which when burned gives off sulfur dioxide gas, is the oldest known insecticide, when brimstone was used as a fumigant up to 3,000 years ago. It was used in the past against mildew and to sanitize houses quarantined due to infectious diseases such as [[smallpox]] and to kill household insects.<ref>The Environment and Encyclopedia Directory, 2001, Third Edition, p. 135</ref> Anecdotal<ref>http://thebedbugresource.com/phpBB2/viewtopic.php?t=623</ref> and clinical  reports testify of the past use of  fumigation with sulfur dioxide (such as through the use of sulfur candles) showing that it was highly effective against bedbugs. In the late 1930 to the mid 1940s it was used in the United Kingdom to fumigate entire homes, and it is reported to have helped reduce infestations by up to 80% in one town under study.<ref>Busvine J.R. 1964. Medical Entomology in Britain. Ann. of App. Biol. 53: 190-199</ref> One recommendation was the use of 20 fluid ounces of liquefied sulfur dioxide to 1200 cubic inches with a repeat treatment within two weeks.<ref> [http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2369743/pdf/brmedj07360-0033b.pdf British Medical Journal], p. 885, Nov. 11. 1933</ref>

However, despite its historical use and effectiveness, it apparently is no longer legal to sell for consumer use in homes, although it may be used in greenhouses and possibly by professional exterminators in some cases, as it is dangerous to use due to the poisonous and suffocating vapors of the sulfur dioxide gas, while its chemical action on metals and coloring fabrics may leave undesirable effects.<ref>[http://www.google.com/url?sa=t&source=web&cd=9&ved=0CF4QFjAI&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fpmc%2Farticles%2FPMC2218860%2Fpdf%2Fjapha00004-0001b.pdf&ei=_7fkTMOcM4X7lwfpgvC1Cw&usg=AFQjCNG9DYw3T_grq4d_oLBTX7x-Wi0yTA&sig2=IawKCwC3s8zx6H7WlD9T3A Journal of the American Public Health Association,] p. 232, April, 1911</ref> Factors adversely affecting its effectiveness include the difficulty in  penetrating all haborages, the higher resistance of eggs to the fumigant, while starvation and cold enhances the resistance of all bedbugs.<ref>http://newyorkvsbedbugs.org/2009/06/15/the-challenges-in-1941</ref> To be efficient it must burn rapidly,  and some studies report it is not always successful. More clinical studies are needed in order to ascertain its effectiveness and the best manner of treatment. <ref>[http://onlinelibrary.wiley.com/doi/10.1111/j.1744-7348.1940.tb07481.x/abstract  H. C. Gough, ''The toxicity of sulphur dioxide to the bed-bug Cimex Lectularius L.'']</ref>

However, despite its historical use and effectiveness, it apparently is no longer legal to sell for consumer use in homes, although depending on location it may be used in greenhouses and possibly by professional exterminators in some cases, as it is dangerous to use due to the poisonous and suffocating vapors of the sulfur dioxide gas, while its chemical action on metals and coloring fabrics may leave undesirable effects.<ref>[http://www.google.com/url?sa=t&source=web&cd=9&ved=0CF4QFjAI&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fpmc%2Farticles%2FPMC2218860%2Fpdf%2Fjapha00004-0001b.pdf&ei=_7fkTMOcM4X7lwfpgvC1Cw&usg=AFQjCNG9DYw3T_grq4d_oLBTX7x-Wi0yTA&sig2=IawKCwC3s8zx6H7WlD9T3A Journal of the American Public Health Association,] p. 232, April, 1911</ref> Factors adversely affecting its effectiveness include the difficulty in  penetrating all haborages, the higher resistance of eggs to the fumigant. Starvation and cold are factors which enhance the resistance of all bedbugs.<ref>http://newyorkvsbedbugs.org/2009/06/15/the-challenges-in-1941</ref> To be efficient it must burn rapidly,  and some studies report it is not always successful. More clinical studies are needed in order to ascertain its effectiveness and the best manner of treatment. <ref>[http://onlinelibrary.wiley.com/doi/10.1111/j.1744-7348.1940.tb07481.x/abstract  H. C. Gough, ''The toxicity of sulphur dioxide to the bed-bug Cimex Lectularius L.'']</ref>

====Carbon Dioxide====

====Carbon Dioxide====