Wood Chair Safety

Wood is frequently used to construct a wide array of chairs for use at the home, office, restaurants, hotels and other establishments. These chairs range from simple four-legged, school-style chairs to three-legged bar stools. Wood is an excellent choice for chairs due to its inherent beauty and durability if properly maintained.

I have been an expert witness in legal cases involving failure of wooden chairs and many of which could have been prevented.  Chair accidents are often not the result of a single incident but rather the culmination of years of abuse or neglect. Wood and metal both can degrade over time, especially in humid or other adverse conditions. Metal fasteners are subject to corrosion and can fail due to repeated or excessive wear due to a condition known as metal fatigue.

Accidents are due to a problem in at least one of these three areas: (1) improper maintenance, (2) design defect and (3) manufacturing defect. The more of these areas that you can control, the lower your risk of a chair-related accident.

Maintenance

Wood chairs should be routinely inspected to help ensure that the chair will perform as it is intended and in a safe manner. Homeowners should follow these simple guidelines when inspecting their chairs. Inspection will not guarantee you will not have an accident but will certainly reduce the risk.

Does the chair appear stable or does it wobble? Is any of the wood soft or display evidence of insect attack?
Do the joints appear solid? Pieces of wood were either joined with glue or a fastener. In either case, the joint can degrade over time, and the integrity of the joint can be examined visually and by applying different loads to the chair.

Design

Homeowners are typically not responsible for the design of the chair. If a product has a design defect, then all of the products manufactured using this design are flawed and dangerous. A product can have a design defect if a foreseeable risk of harm could have been reduced or otherwise eliminated by using an alternate design and the failure to use such an alternate design resulted in an unsafe condition. A chair may be safe for a large person to gently sit but may fail if the person abruptly sits down. Such a chair may be designed for a static load rather than a dynamic load and if so would have a design defect.

Many chair accidents involve the failure of a critical load-bearing component. This is generally classified as a design failure. Common design defects include improper sizing or bracing of chair legs.

Manufacturing

Again, homeowners are typically not responsible for the manufacturing of a chair. Manufacturing defects occur due to mistakes or other problems during the assembly of the product. So, in this case, some of the products using a given design are safe and others are unsafe. Manufacturing defects can occur if another species or grade of wood is used rather than what was specified in the design. A common manufacturing defect is a “starved” glue joint. This occurs when either too little glue is used or too much pressure is applied to a glue joint and results in an inadequate amount of glue in the joint. The joint is then compromised and subject to failure.

Disclaimer

This article is not intended as a substitute for legal advice for individuals involved in a chair-related accident nor should it be interpreted as legal advice or opinion. This article is based on available information as of the time of its posting and is intended for general information purposes only. All users of chairs are encouraged to read and follow proper safety rules and be familiar with all applicable government regulations and standards before using a chair.

Todd Shupe is the President of DrToddShupe.com and is a well recognized expert on wood-based housing and building materials, wood decay and degradation, and wood science. Shupe worked as a professor and lab director at LSU for over 20 years. He is active in several ministries including his Christian blog ToddShupe.com. Todd is the President of the Baton Rouge District of United Methodist Men, and Board Member for Gulf South Men and a Team Leader for The Kingdom Group. He is a volunteer for the Walk to Emmaus, Grace Camp, and Iron Sharpens Iron. Todd is a Men’s Ministry Specialist through the General Commission of United Methodist Men and is in training to be a Certified Lay Minister through the Louisiana Conference of the United Methodist Church.

Wood from a West Coast Cedar Tree May Help Find a Cure for Prostate Cancer

Natural Drugs

If a man lives long enough, he will develop prostate cancer.  The many commercially available anticancer drugs can be classified by origin as either chemical synthetic drugs or natural drugs derived from various kinds of organisms. Natural medicine for cancer therapy has proved to be effective and less toxic on normal cells, with fewer side effects. Prodigiosin did not cause death in vitro to lymphocytes at effective concentrations (<100 nM) and also did not show toxicity in vivo to lymphoid organs at effective dosages (10 and 30 mg/kg). The discovery of anticancer drugs has mainly resulted from screening of natural products and their analogs. Some natural plant metabolites are believed to have anticancer properties; these include several pigments, quinines, and alkaloids. Secondary metabolites from microorganisms are more practical for development as therapeutic agents.

Prodigiosin

As an anticancer drug, prodigiosin shows its anticancer activity by inhibiting or activating some signaling pathways that have not been clearly understood before. Prodiginines (PGs) are a family of tripyrrole red pigments receiving increasing interest because of their numerous biological activities, including antifungal, antibacterial, antiprotozoal, antimalarial, immunosuppressive, and anticancer activities. Specially, prodigiosin has been effective in tumor cell inhibition and cell apoptosis induction. Prodigiosin is a secondary metabolite produced from Serratia species and other unrelated microbial strains, such as Streptomyces griseoviridisPseudomonas magnesioruberaVibrio species, and other marine bacteria. Some of the enzymes involved in the biosynthetic pathways that produce prodigiosin are now known, and some of the corresponding genes have been identified and cloned, but the biosynthetic pathway is still poorly understood. Prodigiosin production in some producer organisms, such as Serratia and Streptomyces, is now well understood, as well as its physiology and regulation. However, its biological role in these organisms remains unclear.

Fixation is a chemical process in which the preservative chemically bonds to the wood. It is well recognized that exposure of CCA-treated wood to an acid solution can re-oxidize the chromium thereby converting the CCA elements into their water-soluble form. Thus, acid extraction using different acids and wide ranges of reaction conditions has been extensively studied for removal of CCA from out-of service CCA-treated wood (Shiau et al. 2000; Clausen 2004; Humer et al. 2004; Kazi and Cooper 2006; Gezer et al. 2006; Kakitani et al. 2007; Janin et al. 2009). These studies have shown that the recovery of CCA elements from CCA-treated wood can be obtained with many organic acids, such as oxalic, acetic, citric, and formic acids; however, the acid extraction process is slow. Therefore, cost-effective acid extraction methods are lacking.

Chamaecyparis lawsoniana 

Chamaecyparis lawsoniana is known to have significantly high levels of natural durability and termiticidal activity due to the inherently high attractive content of its heartwood. In this paper, we described the isolation of a prodigiosin-producing bacterium, HDZK-BYSB107, collected from Port Orford Cedar (POC), Clawsoniana, in Oregon, USA. The prodigiosin-producing strain was identified as Serratia marcescens subsp. lawsoniana. We extracted and purified a red pigment from this strain and identified it as prodigiosin by ultraviolet absorption analysis, mass spectrographic analysis, LC-MS, and NMR spectroscopy. Therefore, to explore the anticancer activities and mechanism of the bacterial prodigiosin, we performed this study using human choriocarcinoma (JEG3) and prostate cancer cell lines (PC3) in vitro, and JEG3 and PC3 tumor-bearing nude mice in vivo.

Findings

 Our results suggested that the bacterial prodigiosin had strong antibacterial, anticancer, and proapoptotic activities against cancer cells and raises the possibility of its use as a chemotherapeutic drug in future.  Together with its excellent anticancer activity, the anticancer mechanism was further verified by JEG3 and PC3 cells. We confirmed that the bacterial prodigiosin promotes cancer cell apoptosis. Thus, we concluded that the HDZK-BYSB107 prodigiosin could be considered as a non-toxic anticancer drug in the near future.

Todd Shupe is the President of DrToddShupe.com and is a well recognized expert on wood-based housing and building materials, wood decay and degradation, and wood science. Shupe worked as a professor and lab director at LSU for over 20 years. He is active in several ministries including his Christian blog ToddShupe.com. Todd is the President of the Baton Rouge District of United Methodist Men, and Board Member for Gulf South Men and a Team Leader for The Kingdom Group. He is a volunteer for the Walk to Emmaus, Grace Camp, and Iron Sharpens Iron. Todd is a Men’s Ministry Specialist through the General Commission of United Methodist Men and is in training to be a Certified Lay Minister through the Louisiana Conference of the United Methodist Church.