Industrial Hygiene and Toxicology - Research Paper Example

Industrial Hygiene Formaldehyde Formaldehyde is a volatile compound having a pungent odour which is the most common air polluting agent. It occurs naturally and is also produced in quite larger quantities for consumer products, industrial purposes like manufacturing of plastics and chemicals and building products, like manufacturing woods. The fumes of formaldehyde can enter indoors from fibreboards, plywood, particleboard, foam insulations, carpets, fibreglass, paints and floor finishes. Formaldehyde can also be found in automobile exhaust whereas cosmetic nail colours and nail hardeners also contain some amounts of formaldehyde. The root of exposure to formaldehyde is either by inhaling, absorbing through skin or swallowing. In any case, it is highly toxic in nature. Formaldehyde can be either inhaled by the workers in the form of gas or vapour or absorbed in the skin in the form of a liquid. Exposure occurs through air fresheners, disinfectants, cleaners, fabric softeners, furniture and flooring, cosmetic nail colours and hardeners draperies and wall paper adhesives. Below are the formaldehyde exposure levels according to Boegli (314). Acute reference exposure level: 44ppb may cause mild or moderate eye irritation. 8-hour reference exposure level: 7 ppb may cause respiratory symptoms like asthma. Chronic reference exposure level: 7 ppb may cause respiratory symptoms like asthma. Some kinds of PPE are found to be effective for exposure to formaldehyde. However, PPE should only be used as an addition to engineering controls. PPE that should be used when contacting wit formaldehyde are: Impermeable gloves Eye and face protection Lab coats Respiratory protection NIOSH has come out with ways to use formaldehyde which are appropriate for personal, monitoring and occupational use. Some of these methods are: NOISH method 2016, 2541 and 3500. According to the method of 2016, a sample of air is obtained by using a cartridge which is filled with silica gel also known as 2,4 dinitrophenylhydrazine. A sample is then obtained by using carbonyl free acetonitrile and analyzed by UV and HPLC detection. A sampling pump is used to draw air through the cartridge. The recommended flow rate of the pump is estimated to be 0.03 to 1.5 L/min to attain a volume that is in the range of 1 and 15 L. The working range is suggested to be 0.015 to 2.5mg/m³ for a sample of 15L of air. Other NIOSH methods like 2541 and 3500 make use of similar techniques to determine formaldehyde in air (Reed 335). Naphthalene Naphthalene is an aromatic polycyclic hydrocarbon class of chemicals which can be seen as white solid. Having a pungent odour, quite many household products are made from naphthalene: for example, moth balls and deodorant blocks for toilet use. Naphthalene occurs naturally in the fossil fuels of coal and petroleum. Burning of wood or tobacco produces naphthalene. It is also used to make dyes, plastics, tanning agents for leather and insecticides. However, it breaks down quite fast. Exposure to naphthalene can occur through accidental ingestion, contaminated water, from food (if cows and chicken are exposed to naphthalene), through skin and inhaling industrial emissions. According to the most recent OSHA standard, naphthalene is 10 parts of naphthalene per million part of air that is ppm. This can also be represented as 50 mg of naphthalene per cubic meter of air. Employees working closely with naphthalene should be provided with adequate clothing like gloves, lab coats and face shields. In case if the clothing gets contaminated with naphthalene, employees should change immediately to uncontaminated clothing. Dust and splash-free safety goggles are also required by the employees in order to avoid contact of solid or vaporized naphthalene with eyes. Appropriate respiratory protection should also be provided to the employees: it should include a full face piece, dust filter and organic vapour cartridge. To obtain air samples for detecting naphthalene, the samples are collected on charcoal tubes. According to NIOSH methods, naphthalene is a compound that can exist both in vapour state and particle phase in air; hence, collection of samples on charcoal tubes is preferred. The collected samples are then desorbed with carbon disulphide and later on gas chromatography is detected by making use of the flame ionization detector. Apart from flame ionization detector (FID), photo ionization detector (PID), ultraviolet detection (UV), florescent detection (FD) or Fourier transform infrared detection (FTIR) methods can be used to determine the presence of naphthalene in air (Reed 189). Hexavalent Chromium Chromium hexavalent compounds, often termed as hexavalent chromium, exist in various forms. Industrial use includes chromate pigments added in paints, dyes, and ink. Chromates are also added as anti-corrosives in primers, paints and surface coatings which are alike. Chromic acid is used for protective coating especially on metallic substances. Hexavalent chromium can be produced by different methods such as welding steel or chromium metal. In these cases chromium does not come to be in the true hexavelent state however as the high temperature oxidizes the metal. The major route of exposure for hexavalent chromium is either by vapours or dust. This route of exposure is of primary concern. The main risk associated with hexavalent chromium is an increased risk of cancer. Eating fresh vegetables, fruits, fish, meat and poultry humans can get exposed to chromium. Important to note that drinking water cannot be a route to exposure however, plants can absorb chromium which increases the risks to those who eat the plants. Contact with contaminated soil may result in exposure to chromium which can be reduced by regularly washing open areas like hands feet and face. According to NIOSH, the occupational exposure to Chromium Hexavalent is 0.2 μg / m3 for 8-hours per day. However, for inhaling chromium hexavalent for more than applicable exposure limits can result in running nose, itching, ulcers, nosebleeds and holes in the nasal spectrum. Respirators should be used by the employees in close contact with chromium hexavalent as they will protect from hazardous dust particles, fumes or vapours. Apart from this protective clothing, it is helpful to use gloves, head protection, some kind of glasses or goggles, foot protection, body suits or aprons. Contaminated PPE should be held with more care and kept in sealed bags as they may shed large amounts of hazardous dust if shaken or blown. According to the NIOSH method 7600 for sampling of chromium hexavalent, sample is collected on 5.0 um pore size and 37 mm in diameter PVC filter which is fitted in polystyrene cassette filter holder. Care should be taken to avoid exceeding 1mg of dust gathering on the filter. After the collection of the sample the filter is removed from the cassette. Analysis of the sample should be completed within two weeks, and it requires no refrigeration for the sample. (Reed 256). Works Cited Boegli, W J. Oxidation of Formaldehyde Solutions Used for the Preservation of Reverse Osmosis Membranes: Phase Ii. Denver, Colo: Applied Sciences Branch, Division of Research and Laboratory Services, Engineering and Research Center, U.S. Dept. of the Interior, Bureau of Reclamation, 1987. Print. Eller, Peter M, and Mary E. Cassinelli. Niosh Manual of Analytical Methods. Cincinnati, Ohio: U.S. Dept. of Health and Human Services, Public Health Service, Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health, Division of Physical Sciences and Engineering, 1994. Continually updated resource. Reed, L D. Niosh Comments on the Environmental Protection Agency's Proposed Rule on Proposed Prohibition of Hexavalent Chromium Chemicals in Comfort Cooling Towers. Springfield, VA: NTIS, 1988. Print. Read More