Progress 06/15/09 to 06/15/12
Outputs
OUTPUTS: The research team included Robert Coleman (Summerdale, Inc., Verona, WI) and Carol Clausen, Vina Yang and Patti Lebow (US Forest Service, Forest Products Laboratory, Madison, Wisconsin) and support staff at the US Forest Service, Forest Products Laboratory and Summerdale, Inc. Objective #1. Identified those combinations of fatty acids (C3, C7 - C9 and C8/C10 mix), emulsifiers (Emsorb 6915 and PE 1198), synergist (i.e., L-lactic acid) and adjuvants (Competitor, Sylgard 309, ProNatural, Surflex QW391 and Exacto 390) that were stable as formulation concentrates (greater than 2 months) and also stable as dilutions in water at 10, 30 and 60 minutes. Moldicide formulations included active ingredients (fatty acids) and a synergist (i.e., L-lactic acid) that were: cost effective, natural, GRAS compounds and compatible in effective moldicide formulations. The three primary ingredients in the moldicide formulation were: a) an active ingredient (AI) or fatty acid (C3, C7 - C9 and C8/C10 mix), b) a synergist (i.e., L-lactic acid) and c) an emulsifier (using a dual emulsification system). Objective #2: Determined which fatty acid species (C3, C7 - C9, C8/C10) was most effective as an anti-sapstain and wood moldicide, using experimental formulations comprising a dual emulsification system (sorbitan monolaurate and phosphate ester), an organic acid synergist (i.e., L-lactic acid) and/or adjuvant designed to increase formulation distribution and penetration. Application via dip and vacuum-pressure treatments were evaluated for treated, kiln-dried southern yellow pine (SYP). Moldicide activity of leached versus unleached, C8-treated stakes were also evaluated to determine whether C8 and/or selected adjuvants remained in SYP after prolonged exposure to water. Test organisms and inoculum preparation: Mold fungi, Aspergillus niger 2.242, Penicillium chrysogenum PH02, and Trichoderma viride 20476 were grown on 2% malt agar and individual spore suspensions were prepared by washing the surface of a 2-wk old culture of each fungus with 10 mL of sterile deionized (DI) water according to ASTM standard D4445-91 (1998). Mold test (southern yellow pine stakes): Specimens (7 x 20 mm cross section by 7 cm long and 75 x 100 mm by 12.5 mm thick) were cut from southern pine and conditioned at 27 degrees, C, 70% relative humidity (RH). Twelve random replicate specimens were dip-treated for ~30 seconds in each moldicide formulation and held overnight according to the ASTM standard test method D4445-91 (1998) or ASTM D3273-00 (1986). For the stake test, treated specimens were arranged over 4 layers of blotting paper saturated with 25 mL DI water and a polyethylene mesh spacer in sterile disposable Petri dishes (150 x 25 mm). Untreated specimens dipped in DI water served as controls. Specimens were sprayed with 1 ml of individual mold spore inocula, sealed in polyethylene bags to prevent drying and incubated at 27oC and 70% RH for 8 - 12 weeks. Only formulations that provided the best protection from consortia of test fungi were further tested on large specimens (planks) against a mixed mold and sapstain inoculum. PARTICIPANTS: Not relevant to this project. TARGET AUDIENCES: Not relevant to this project. PROJECT MODIFICATIONS: Not relevant to this project.
Impacts
Humans are exposed constantly to molds in the environment, both indoors and outdoors. Problems arise when the immune system is suppressed (HIV infection, cancer treatment), over-responsive (allergy) or when exposures are exceedingly high (irritation and mycotoxin effects). Many people are allergic to molds, and allergic responses include hay fever and asthma. Certain molds such as Stachybotrys chartarum (or atra), and various species of Aspergillus, Fusarium and Penicillium produce mycotoxins or volatile organic compounds (VOCs) that can be irritating when present in high concentrations and on occasion, can be quite toxic to humans and animals. Because of the recent increase in mold mitigation claims, as well as increased public awareness about indoor air quality, the need for improved protection of cellulose-based building materials from mold infestations has been hastened. Mold claims, including pre- and post-construction, exceeded $3.0 billion in the U.S. in 2002, more than double the $1.3 billion paid in the previous year. While mold fungi do not cause structural damage to wood, the presence of mold is indicative of inadequate surface drying of condensation, chronic high humidity, or water intrusion. Chronic moisture issues can result in structural damage which often begins with growth of mold fungi followed by presence of decay fungi (i.e., brown-rot and white-rot fungi). Eventually, chronic moisture problems and decayed wood can attract other pests such as termites. Moreover, spores from mold fungi can be particularly problematic not only as human and animal allergens but also due to their recalcitrance to chemical remediation. Among the three primary wood infestations (termite attack, mold and decay fungi), spores from mold fungi appear to be the most resistant to chemical treatments; hence, mold spores are more difficult to suppress and control. A number of problems may attribute to excess moisture in existing structures, such as flawed design, poor construction practices or maintenance, poor site drainage, leaky roofs/plumbing, inadequate insulation, improper ventilation, etc. No matter how meticulous the maintenance on a building is, nearly every structure will encounter a moisture event that may be as obvious as flooding or as subtle as a chronic leak inside a wall that only becomes apparent in advanced stages of biological activity. Since even the best moisture management practices cannot prevent eventual moisture intrusion, economical biocides that are suitable for interior use are needed. In addition to being effective against mold fungi, they must be nontoxic to occupants, nonvolatile, environmentally acceptable, safe to handle, and possess low solubility. Surface treatment of dimension lumber or engineered products with mold inhibitors would add an additional layer of protection for in-service wood products and lessen the impact of current indoor air quality issues.
Publications
- Clausen, C.A., Coleman, R.D. Yang, V.W. 2010. Fatty acid formulations for wood protection. Forest Products Journal, 60, 301 - 304.
- Coleman, R.D. 2010. Coleman Fungicide Compositions. U.S. Patent 7,741,244.
- Coleman, R.D. 2010. Pesticide Compositions and Methods for Their Use. U.S. Patent 7,820,594.
- Coleman, R.D. 2011. Multi-functional wood preservatives based on a borate/fatty acid combination. Filed with the United States Patent and Trade Office, August 31, 2011.
- Coleman, R.D. Clausen, C.A. 2009. Multi-factorial antimicrobial wood protectants. International Research Group on Wood Protection, Stockholm, Sweden. IRG/WP 08-30484.
- Coleman, R., Yang, V.W., Woodward, B., Lebow, P., Clausen, C.A. 2011.Efficacy of fatty acid chemistry: Candidate mold and decay fungicides. Proceedings of American Wood Protection Association, Birmingham, AL. 106, 287 - 297.
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Progress 06/15/09 to 06/14/10
Outputs
OUTPUTS: NON-TECHNICAL SUMMARY: Humans are exposed constantly to molds in the environment, both indoors and outdoors. Problems arise when the immune system is suppressed (HIV infection, cancer treatment), over-responsive (allergy) or when exposures are exceedingly high (irritation and mycotoxin effects). Many people are allergic to molds, and allergic responses include hay fever and asthma. Certain molds such as Stachybotrys chartarum (or atra), and various species of Aspergillus, Fusarium and Penicillium produce mycotoxins or volatile organic compounds (VOCs) that can be irritating when present in high concentrations and on occasion, can be quite toxic to humans and animals. Because of the recent increase in mold mitigation claims, as well as increased public awareness about indoor air quality, the need for improved protection of cellulose-based building materials from mold infestations has been hastened. Mold claims, including pre- and post-construction, exceeded $3.0 billion in the U.S. in 2002, more than double the $1.3 billion paid in the previous year. While mold fungi do not cause structural damage to wood, the presence of mold is indicative of inadequate surface drying of condensation, chronic high humidity, or water intrusion. Chronic moisture issues can result in structural damage which often begins with growth of mold fungi followed by presence of decay fungi (i.e., brown-rot and white-rot fungi). Eventually, chronic moisture problems and decayed wood can attract other pests such as termites. Moreover, spores from mold fungi can be particularly problematic not only as human and animal allergens but also due to their recalcitrance to chemical remediation. Among the three primary wood infestations (termite attack, mold and decay fungi), spores from mold fungi appear to be the most resistant to chemical treatments; hence, mold spores are more difficult to suppress and control. A number of problems may attribute to excess moisture in existing structures, such as flawed design, poor construction practices or maintenance, poor site drainage, leaky roofs/plumbing, inadequate insulation, improper ventilation, etc. No matter how meticulous the maintenance on a building is, nearly every structure will encounter a moisture event that may be as obvious as flooding or as subtle as a chronic leak inside a wall that only becomes apparent in advanced stages of biological activity. Since even the best moisture management practices cannot prevent eventual moisture intrusion, economical biocides that are suitable for interior use are needed. In addition to being effective against mold fungi, they must be nontoxic to occupants, nonvolatile, environmentally acceptable, safe to handle, and possess low solubility. Surface treatment of dimension lumber or engineered products with mold inhibitors would add an additional layer of protection for in-service wood products and lessen the impact of current indoor air quality issues. PARTICIPANTS: Nothing significant to report during this reporting period. TARGET AUDIENCES: Nothing significant to report during this reporting period. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
APPROACH: The research team will include Robert Coleman (Summerdale, Inc., Verona, WI) and Carol Clausen, Vina Yang and Patti Lebow (US Forest Service, Forest Products Laboratory, Madison, Wisconsin) and support staff at the US Forest Service, Forest Products Laboratory and Summerdale, Inc. Objective #1. Identify those combinations of fatty acids (C3, C7 - C9 and C8/C10 mix), emulsifiers (Emsorb 6915 and PE 1198), synergist (L-lactic acid) and adjuvants (Competitor, Sylgard 309, ProNatural, Surflex QW391 and Exacto 390) that are stable as formulation concentrates (greater than 2 months) and also stable as dilutions in water at 10, 30 and 60 minutes. Moldicide formulations will include active ingredients (fatty acids) and a synergist (L-lactic acid) that are: cost effective, natural, GRAS compounds and compatible in effective moldicide formulations. The three primary ingredients in the moldicide formulation will be: a) an active ingredient (AI) or fatty acid (C3, C7 - C9 and C8/C10 mix), b) a synergist (L-lactic acid) and c) an emulsifier (using a dual emulsification system). Objective #2: Determine which fatty acid species (C3, C7 - C9, C8/C10) is most effective as an anti-sapstain and wood moldicide, using experimental formulations comprising a dual emulsification system (sorbitan monolaurate and phosphate ester), an organic acid synergist (L-lactic acid) and/or adjuvant designed to increase formulation distribution and penetration. Application via dip and vacuum-pressure treatments will be evaluated for treated, kiln-dried southern yellow pine (SYP). Moldicide activity of leached versus unleached, C8-treated stakes will also be evaluated to determine whether C8 and/or selected adjuvants remain in SYP after prolonged exposure to water. Test organisms and inoculum preparation: Mold fungi, Aspergillus niger 2.242, Penicillium chrysogenum PH02, and Trichoderma viride 20476 will be grown on 2% malt agar and individual spore suspensions will be prepared by washing the surface of a 2-wk old culture of each fungus with 10 mL of sterile deionized (DI) water according to ASTM standard D4445-91 (1998). Mold test (southern yellow pine stakes): Specimens (7 x 20 mm cross section by 7 cm long and 75 x 100 mm by 12.5 mm thick) will be cut from southern pine and conditioned at 27degrees, C, 70% relative humidity (RH). Twelve random replicate specimens will be dip-treated for ~15 seconds in each moldicide formulation and held overnight according to the ASTM standard test method D4445-91 (1998) or ASTM D3273-00 (1986). For the stake test, treated specimens will be arranged over 4 layers of blotting paper saturated with 25 mL DI water and a polyethylene mesh spacer in sterile disposable Petri dishes (150 x 25 mm) (B-D Falcon, Los Angeles, CA, USA). Untreated specimens dipped in DI water will serve as controls. Specimens will be sprayed with 1 ml of individual mold spore inocula, sealed in polyethylene bags to prevent drying and incubated at 27oC and 70% RH for 8 - 12 weeks. Only formulations that provide the best protection from consortia of test fungi will be further tested on large specimens (planks) against a mixed mold and sapstain inoculum.
Publications
- Coleman, R. D. and C. A. Clausen. 2009. Multi-factorial Antimicrobial Wood Protectants. International Research Group on Wood Protection, Stockholm, Sweden. IRG/WP/08-30484. 10p.
- Clausen, C. A. and R. D. Coleman and V. W. Yang. 2010. Fatty acid Formulations for Wood Protection. Forest Products Journal. 60:301 - 304.
- Clausen, C. A., V. Yang and R. Coleman. 2010. Fatty Acid Formulations for Wood Protection. 64th International Convention. Forest Products Society. Madison, WI.
- Coleman, R., V. Yang, B. Woodward, P. Lebow and C. Clausen. 2010. Efficacy of Fatty Acid Chemistry: Candidate Mold and Decay Fungicides. American Wood Protection Association, Savannah, GA.
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