This study tested the effect on the toxicity of formaldehyde to select a shelter site due to formaldehyde leakage. As a result of the experiment, the range of ERPG-2 and 3 is between 2.2km and 9.6km, ASET is 6 minutes at 1km, 15 minutes at 3km, 22 minutes at 5km, and the lethality rate is 99.9% at 1km and 9% at 3km. In areas where refuge time is less than 15 minutes or the lethality rate is more than 2%, a shelter is installed. This is because if there are only a few evacuees, the evacuation time may take longer than the pre-movement time of 15 minutes or less specified in PD 7974-6:2004, and the lethality rate with the lowest number of deaths was calculated to be 2%. The shelter must be equipped with a hepa-filter, positive pressure equipment, air purifier, air respirator, goggles, chemical protective clothing type 4 and sufficient parking space must be secured to ensure the safety of evacuees.
In this study, we examined the residual amounts of formaldehyde in hygiene products to determine the safety of these products in Gyeonggi-do. Formaldehyde is among the harmful substances that may remain within certain hygiene products. On the basis of an analysis of formaldehyde in a total of 222 items (6 disposable paper straws, 9 disposable paper napkins, 21 toilet papers, 13 disposable dishcloths, 16 disposable paper towels, 32 wet wipes for food service restaurants, 25 disposable cotton swabs, and 100 disposable diapers), we detected traces in three wet wipes for food service restaurants (1.87 to 4.45 mg/kg), which is approximately 9% to 22% of the standard level (20 mg/kg). We established that all the hygiene products assessed in the study met the individual standards for formaldehyde, thereby confirming that safe products are being distributed. In the standards and specifications for hygiene products, the formaldehyde test method is regulated for application with respect to three categories based on the type of product. The samples used in this study were of types for which method 1 or method 2 is applied, and the limits of detection, limits of quantification, linearity, and recovery rates were reviewed to verify the validity of each test method. When method 2 was applied, we experienced interference when performing analysis at a wavelength of 412 nm, which was associated with the influence of impurities in some samples of disposable cotton swabs and disposable diapers. Consequently, in these cases, the results were compared after analysis using method 1. By comparing the results obtained using method 2 with those obtained using method 1, the latter of which were unaffected by the interference of impurities, we were able to detect formaldehyde at low concentrations. These findings accordingly highlight the necessity to standardize the formaldehyde test method for future analyses.
위생용품의 기준 및 규격서에는 포름알데히드 함량 시 험법이 위생용품 유형별로 다르게 규정되어 있다. 위생용품 유형별로 미용티슈, 기저귀 안감 및 방수층, 팬티라이너를 대표 시료로 하여, 2,4-DNPH/HPLC법, 아세틸아세톤 /분광광도계법, 아세틸아세톤/HPLC법을 비교 분석하였다. 시험방법의 유효성 확인을 위하여 위생용품 유형별로 직선성과 검출한계, 정량한계, 회수율, 반복성 등을 검토하였다. 포름알데히드 표준용액으로 검량선을 작성 한 결과 3가지 시험방법에서 모두 상관계수(R2)가 0.999이상이었고, 검출한계와 정량한계는 위생용품의 기준 및 규격에 규정 된 각각의 최대잔류허용기준(Maximum Residue Level, MRL)에 비해 매우 낮게 나타났다. 또한 80%이상의 양호한 회수율을 확인할 수 있었고, 반복성(repeatability)도 20% 이내에 해당하여 양호하였다. 분석장비 별 비교에서는 분광광도계에 비하여 HPLC는 낮은 검출한계 및 정량한계 를 나타내어 정밀한 것으로 나타났다. 또한 유도체화 후 차광을 유지하면서 분석이 가능한 장점이 있었다. 유도체화 시액별 시간 경과에 따른 포름알데히드 안정성 평가를 위하여 2,4-DNPH와 아세틸아세톤으로 유도체화 한 후 0, 3, 6, 9, 24, 48 시간에 HPLC로 포름알데히드를 분석하였다. 2,4-DNPH로 유도체화 된 포름알데히드의 경우 시간의 경과에 따른 포름알데히드 피크면적의 통계적 유의성 은 보이지 않았다(P>0.05). 반면, 아세틸아세톤의 경우 유 의적인 상관관계를 보였는데(P<0.01), 아세틸아세톤-포름 알데히드 면적과 시간과는 음의 상관계수(r)를 보였다. 최초로 측정된 포름알데히드 피크면적평균 대비 시간대 별 피크면적평균 비교에서는 2,4-DNPH 시액으로 유도체화 한 경우에는 면적비의 특별한 증감이 관찰되지 않아 안정한 것으로 나타났다. 그러나 아세틸아세톤으로 유도체화 한 경우에는 시간의 경과에 따라 감소 경향을 보이다가 48시간 경과 후에는 81.3-95.2% 수준으로 감소하는 것으로 나타났다. 위생용품은 대부분 일회용으로 제조가 용이한 종이와 부직포 재질로 만드는 경우가 많고, 제조과정 중 접착제를 사용한다. 따라서 위생용품 최종제품에도 포름알데히드가 잔존할 가능성이 있다. 우리나라에서도 위생용품관리법으로 위생용품 중의 포름알데히드 기준을 마련하여 관리하고 있으나 시행 초기로 국내 유통 제품에 대한 포름알데히드 잔류 실태조사는 미흡한 실정이다. 이에 본 연구에서는 부산지역에서 유통 중인 위생용품 총 205건을 대상으로 포름알데히드 함량 모니터링을 실시하였다. 일회용 기저귀 74건 중 73건에서 0.13-29.87 mg/kg 의 수준으로 낮은 농도의 포름알데히드가 잔류되어 있음 을 확인하였다. 이에 일회용 기저귀는 피부에 직접 접촉 하는 부분을 중심으로 지속적인 관리가 필요할 것으로 생각된다. 반면 화장지 78건, 일회용 타월 27건, 일회용 행주 12건, 종이컵 7건, 일회용 종이냅킨 6건, 종이빨대 1건 에서는 포름알데히드가 모두 검출되지 않아 안전하게 관리되고 있음을 알 수 있었다.
본 연구는 스파티필름의 수분 스트레스 정도에 따라 실내 공간 내 오염물질 제거 효율을 구명하고자 수행하였다. 식물이 없는 공간을 대조구, 정상적인 스파티필름과 수분 스트레스를 받은 스파티필름을 각각의 처리구로 하였다. 스파티필름의 수분 스트레스 유무에 따른 chamber 내 온도를 조사한 결과 대조구와 처리구 모두 식물의 생육 적정 범위인 23±1℃를 유지하였으며, 처리 간의 0.7℃의 차이를 보였다. 습도의 경우 대조구와 처리구는 유의차 있게 나타났으며, 처리 간의 유의 차는 없는 것으로 나타났다. 수분 스트레스에 따른 실내 오염 물질을 조사한 결과, 포름알데히드(Formaldehyde) 경우 대조구는 0.30mg・m-3, 정상적인 스파티필름은 0.05mg・m-3 , 수분 스트레스를 받은 스파티필름은 0.09mg・m-3으로 대조구와 처리구는 통계적으로 유의차를 보였으며, 식물 내 수분 스트레스에 따른 처리구간에는 유의차가 없었다. TVOC(Total Volatile Organic Compound)조사 결과, 정상적인 스파티필름의 TVOC는 5시간 후 0.00mg・m-3 으로 모두 제거 된 반면, 수분 스트레스를 받은 스파티필름은 0.34mg・m-3으로 다소 남아 있었으며, 대조구는 1.25mg・m-3으로 세 처리 모두 통계적으로 유의차 있게 나타났다. 또한 이산화탄소 변화량 조사결과, 대조구는 459ppm, 정상 스파티필름은 446ppm으로 통계적으로 유의한 차이는 없으며, 수분 스트레스를 받은 스파티 필름이 대조구보다 이산화탄소 함량이 다소 높았다. 기공변화율 조사 결과, 정상 스파티필름의 변화율은 높게 나타났으며, 수분 스트레스를 받은 스파티필름은 변화율이 낮은 것으로 조사되었다. 따라서, 스파티필름이 배치되어있지 않은 공간보다 배치된 공간이 공기정화에 효과적이며, 수분 스트레스를 받은 스파티필름은 실내오염물질 제거에 있어서 기공 변화율 및 이산화탄소 흡수능력이 저하되므로 스파티필름을 이용하여 효과적으로 실내오염물질을 제거하기 위해서는 적절한 수분 관리가 필요한 것으로 판단된다.
This study measured concentrations of formaldehyde, a pollutant in the indoor air in three departments, before and after the renovation of a medical facility used by the general public, and conducted a health survey on workers' subjective symptoms. The average concentration of formaldehyde was 25.8 ± 8.7 μg/m3 before the renovation and 47.3 ± 6.7 μg/m3 after the renovation. The concentration was increased; however, it did not exceed the maintenance standard set by the law. Measured concentration was high both before and after the renovation in the office, and the biggest difference was shown in the concentration change. For eight symptoms including dry throat, there were more workers who expressed the symptoms after the renovation than those who expressed them before the renovation. Factors that influenced subjective symptoms were the effects before and after the renovation. Even when formaldehyde does not exceed the maintenance standard set by the law, detailed and systematic management is required and adequate health effect evaluation or education is necessary, considering the characteristics of medical facilities.
The potential use of UV-TiO2 photocatalytic oxidation absorbent reactor in the removal of gaseous formaldehyde was studied. This study was conducted inside a bench-type circulation reactor chamber at ambient air conditions. PCO (Photocatalytic Oxidaion) degradation test for formaldehyde was done repeatedly and the average was reported. It was evident that photocatalytic oxidation was proven to be an effective method to control indoor air pollutants, like formaldehyde in indoor air. However, by-products are produced in the case of formaldehyde degradation also CO2, CO, H2O and formic acid are produced. These by-products can inhibit the active site of the photocatalyst. Thus, addition of adsorbent succeeding the PCO-TiO2, acts as a secondary treatment wherein produced by-products from the degradation and unreacted HCHO will adhere to the surface of the adsorbent. In this study, synthetic zeolite and activated carbon pellets were used to control of by-products of formaldehyde. PCOTiO2 degradation alone achieves 86% for a period of 60 minutes. Addition of adsorbent improves the removal efficiency achieving 90% and 96% using activated carbon pellet and zeolite, respectively.
Our objective in this study is to assess the safety of docosahexaenoic acid (DHA) fortified milk of dairy cows fed feeds containing protected fish oil treated with formaldehyde by analyzing formaldehyde concentration in commercial milk and DHA fortified milk of dairy cows fed formaldehyde treated feed. There are 3 milk samples in this study: Commercial milk (CM), DHA fortified milk for Kid (DHA-K) and DHA fortified milk for Baby (DHA-B). We confirm the fresh quality of these three samples by physicochemical tests. In fat content result, three groups are significantly different at the p < 0.05 by Duncan's multiple range test, but fat content of group DHA-K is about half the level of the other two groups. Protein content of group DHA-K is 1% higher than other two groups. According to the analysis result of DHA content of DHA fortified milk, DHA content of DHA-B is two-fold higher than DHA-K. Similar pattern was seen in the intake based on age. According to HPLC analysis result of formaldehyde concentration in milk, commercial milk and DHA fortified milk are between 0.013 ppm and 0.057 ppm which is formaldehyde standard level in fresh milk settled in WHO (World Health Organization). Three groups have no significantly differences at the p < 0.05 by Duncan’s multiple range test. For this reason, it can be concluded that there is no transition of formaldehyde from dairy cows fed formaldehyde treated feeds to its produced milk. Safety about formaldehyde of DHA fortified milk of dairy cows fed formaldehyde treated feeds is considered similar to commercial milk.
A bake-out process using auto switchgear was carried out to evaluate the reduction effect of the concentration of volatile organic compounds (VOCs) and formaldehyde in newly-built apartments for seven days. The reduction rate of VOCs was observed as followings: 19%, 38%, 89%, 90%, and 96% for benzene, toluene, ethylbenzene, xylene, and styrene, respectively, which satisfies at the indoor air quality standards of newly-built apartment houses in Korea. The reduction rate of formaldehyde was 75%. Those results proved that the bake-out process using auto switchgear was effective for reducing indoor air pollutants.
Absorption characteristics of formaldehyde (one of odors) were investigated using a bubble tank. The capacity of reaction tank made of acrylic is I liter and the experiment was carried out as semi-batch mode (for given absorbent packing, formaldehyde was fed continuously with flow rate of 2 liter/min). As operating variables of experiment, concentration of formaldehyde (400~800 ppm), absorption temperature (25~45℃), and packing volume of absorbent (100~300 mL) were used. The experimental results showed that the removal efficiency of formaldehyde decreased from 5 to 10% as the concentration of formaldehyde and the absorption temperature increased from 400 to 800 ppm, and from 5 to 10%, respectively, while it increased with the increase of the packing volume of absorbent.
The purpose of this study was to assess the removal efficiency of formaldehyde using carbon nano colloid (CNC) which was produced by comparatively easy and cheap method. In this study, carbon nano colloid based on water was produced by an electro‐chemical method. The particles which have mostly a spherical shape whose diameter was, what is called,‘nano‐size’were produced. Non‐woven fabric filter, which is currently on the market as a medium filter, was used for the removal efficiency test. Known concentration (0.5 ppm) of formaldehyde standard gas was used as a pollutant. The overall results indicate that (1) nanosize carbon colloids which have a stable dispersibility of which diameter is approximately 10 nm or less, (2) filters treated with carbon nano colloids showed higher removal efficiency, 44.47 ㎍ of HCHO removed/g of carbon and 19.28 ㎍ of HCHO removed/g of carbon, compared to the control experiment using a normal carbon filter, 1.45 ㎍ of HCHO removed/g of carbon.
Studies on the indoor air quality inside newly producted vehicle have made mainly mention of the concentrations for indoor air pollutants or of subjective symptoms, such as irritated eyes and nose, headache and dizziness. That is, there has been no report about how poor indoor air quality inside newly producted vehicle affects vehicle drivers. We measured the indoor air pollutants inside newly producted vehicle and evaluated the neurobehavioral performance of drivers, using a computerized neurobehavioral test (color word vigilance), between a newly producted and a 11-year-old vehicle. Inside the newly producted vehicle, the formaldehyde concentration with closed window was 19.1㎍/m3. The concentration of VOCs with closed window was 3.9㎍/m3 for benzene, 316.7㎍/m3 for toluene, 20.5㎍/m3 for ethylbenzene, 47.7㎍/m3 for m,p-xylene, 15.1㎍/m3 for o-xylene, and 15.3㎍/m3 for styrene. The neurobehavioral performance of drivers inside newly producted vehicle with the computerized neurobehavioral test was 11.05% lower than that for those inside 11-year-old control vehicle. These results suggest that the poor indoor air quality inside newly producted vehicle affects the neurobehavioral performance of driver and a proper evaluation of the indoor air quality inside newly producted vehicle is required into the health effects of pollutants with objective tool, in addition to the level of pollution.
Novolac is widely used as the primary solid component of most photoresists in semiconductor and microelectronic devices. In this study, novolac resins were prepared by condensation of 35% formaldehyde with phenolic compounds such as m-/p-cresol, 2,5-dimethylphenol and bisphenol A in the presence of oxalic acid as catalyst. The average molecular weight (Mw) of these novolac resins has been varied on the changing of mixing ratio of m-/p-cresol/2,5-dimethylphenol/bisphenol A or formaldehyde/phenolic compound. Also, thermal properties of novolac were observed by TGA.
The deodorization performances of ammonia, acetic acid and acetaldehyde were tested for each of all forty five air cleaners sold in the online shops and department stores. The removal performances of toluene and formaldehyde were also investigated and the results were compared to the deodorization performances for the air cleaners. Filter-type and complex type air cleaners which used activated carbon filters showed superior in odor removal performances to those of ionizer type and wet type air cleaners. Toluene and formaldehyde were readily removed for the most of filter-type and complex type air cleaners. Ionizer air cleaners had little removal ability for the toluene and formaldehyde.
Methanol and formaldehyde were produced directly by the partial oxidation of methane over mixed oxide catalysts. The catalysts were composed of Mo and Bi with late-transition metals, such as Mn, Fe, and Co. The reaction was carried out at 450℃, 50 bar in a fixed-bed differential reactor. The prepared catalysts were characterized by O2-TPD and BET apparatus. Among the catalysts used, the catalyst composed of 1:1:2.5 molar ratio of Mo:Bi:Mn showed the best methane conversion and methanol selectivity. The change in ratio of methane to oxygen affected at the conversion and selectivity, and the most proper ratio was 10:1.5. Methane conversion, methanol and formaldehyde selectivities increased with the surface areas of the catalysts. From the O2-TPD result, it was found that the oxygen species responsible for this reaction might be the lattice oxygen species desorbed at high temperature around 800℃.
Methanol and formaldehyde were produced directly by the partial oxidation of methane. The catalysts used were mixed oxides of late-transition metals, such as Mn, Fe, Co, Ni and Cu. The reaction was carried out at 450℃, 50 bar in a fixed-bed differential reactor. The prepared catalysts were characterized by XRD, TPD and BET apparatus. Of the catalysts, A-Mn0.2-6, which contains 0.2 mole of Mn and calcined at 600℃, showed the best catalytic activity: 3.7% methane conversion, and 30 and 28% methanol and formaldehyde selectivities, respectively. The catalytic activity was changed with the content of Mn and the calcination temperature. Catalytic activity increased with the specific surface areas of the catalysts. With XRD, it was found that the structure of the catalysts are changed with calcination temperature. Through O2-TPD experiment, it was found that the catalysts showing good catalytic activity showed O2 desorption peak around 800℃.
This study was carried out to determine the effects of nitrogen (N) fertilization levels (0, 100 and 200kg/ha) and formaldehyde (0.4,0.8 and 1.2%: w/w CM) on the chemical composition, dry matter (DM) yield and in-vitro dry matter digestibility (IVDMD) of
This study was carried out to investigate the formaldehyde (FA) filtration pattern of additional media for indoor biofilter system. Dry pellet type activated carbon (PAC), activated clay (ACL), zeolite, diatomite, pumice and loess ceramic ball were tested. In the case of dry filter media, formaldehyde purification efficiency was the most excellent with activated clay and then was good with the activated carbon, diatomite, zeolite, and pumice order. PAC and ACL decreased the FA concentration with exponential pattern resulted from dynamic balance between emission and purification. Zeolite, diatomite, pumice, and loess ceramic ball showed high filtration rate at initial time and then increased FA concentration result from breakthrough. PAC, zeolite and diatomite could be recommended as additional filter media for biofilter system considering FA filtration and breakthrough characteristics. FA filtration and breakthrough characteristics were improved with wet media except PAC and ACL. In particular, purification performance improvement and breakthrough mitigation were higher in pumice and loess ceramic balls. PAC+ZEO mixing showed the most high purification performance and breakthrough mitigation in all mixing methods. Thus mixture of PAC with zeolite and vertical mixing could be recommended as additional filter media to improve the FA purification ability and pressure drop with indoor air biofilter system.
포름알데히드의 고농도와 저농도에 따른 식물의 생리적 반응을 보기 위하여 실험을 실시하였다. 실내식물은 관음죽, 팔손이나무, 스킨답서스를 이용하였으며, 포름알데히드는 0, 2(2.5), 10(12.3), 100(123) ppm(mg・m-3)농도로 처리하였다. 그 결과 포름알데히드 처리에 대한 잎 피해증상은 100 ppm의 고농도에서 5시간 처리 후 검은 반점으로 나타났다. 외관상 피해증상은 어린잎과 노화된 모두에서 나타났으며, 팔손이나무의 경우에는 줄기에서도 일부 나타났다. 피해 잎의 책상조직과 해면조직이 파괴되거나 변형되었다. 전체적으로 Peroxidase와 Catalase 함량은 관음죽>팔손이나무>스킨답서스 순서였으며, 처리농도가 높아질수록 함량도 대체로 증가하였다. 피해가 심한 스킨답서스의 경우 고농도 처리시에 기공이 닫히는 비율이 약 80% 가장 높았으며, Catalase 증가량도 가장 컸다. 결과적으로 100 ppm의 고농도에서 포름알데히드 흡수를 저해하기 위해 기공이 닫히거나 효소 함량의 변화가 일부 나타났으나, 저농도에서 적극적 흡수를 위한 반응은 보이지 않았다.
각종 건축재료 등의 실내공기오염원에서 발생되는 유해물질과 밀폐성으로 인한 환기미비가 실내 공기오염을 유발하여 건강에 악영향을 미칠 수 있으며, 오염물질에 따라 실외보다는 실내 공기질이 더 좋지 않은 경우도 많다. 특히 실내 공기질에 영향을 미치는 건강상의 악영향 물질의 대표적인 포름알데히드, 휘발성 유기화합물, 석면, 중금속 등의 다양한 화학물질이 거론되고 있다. 이 중 포름알데하이드는 새집증후군 등 실내 공기질에 영향을 미치는 매우 중요한 유해인자로 알려져 있다. 신축 건물이나 리모델링한 기존 주택의 페인트, 벽지, 바닥재, 가구류, 건축자재 등에서 포름알데히드 물질이 발산되면 두통, 알레르지, 코막힘 등 거주자의 건강에 이상을 주거나 각종 질병에 영향을 미치고 있다. 본 연구는 편백의 가지치기로 발생한 편백나무 잎을 절단기를 이용하여 5 ~ 20 mm 크기로 맞춘 후 수증기 증류법으로 추출한 순수 피톤치드로 포름알데히드 제거 효과를 실험하였다. 실험에 사용하기 위해 아크릴로 제작된 그림 2로 용적이 0.008 m³(가로 20 cm * 세로 20 cm * 높이 20 cm)이고, 측정실내 온도는 25℃ ~ 30℃로 HCHO 검지관을 준비하여 양쪽 끝을 절단하여 그림 1과 같이 가스텍을 이용해 일정량의 시료 가스를 흡인하면, HCHO 검지제와 즉각 반응을 일으켜 입구쪽부터 변색 끝 부분 눈금에 의해 농도를 판독하여 측정하였다. 포름알데하이드 초기 농도를 일정하게 조절한 후 추출된 편백 정유 피톤치드 5 ~ 20 mL를 주입하고 시간의 흐름에 따라 포름알데하이드 가스의 농도변화를 측정하여 그림 3에 나타내었다. 포름알데하이드 초기 농도를 50 ~ 150 ppm를 단계적으로, 시간은 30분부터 1시간 흐름 간격으로 5시간 분석한 결과 제거율은 24% ~ 50%까지 제거된 것으로 분석되어 편백나무 잎의 추출액인 피톤치드가 포름알데히드 제거에 우수함을 알 수 있었으며 실내 공질의 효율성이 있는 것으로 분석되었다.