Chlorophenols (di, tri, tetra)
Description
Chlorophenols have been used as mothproofing agents, miticides, germicides, algicides, fungicides, and wood preservatives and to manufacture of other chemicals. All the chlorophenols have been used as biocides. Chlorophenols with at least two chlorines either have been used directly as pesticides or have been converted into pesticides. 2,4,6-Trichlorophenol was previously used as an antiseptic, a pesticide for wood, leather, and glue preservation and as an anti-mildew treatment. 2,4-Dichlorophenol is a chemical intermediate used principally in the manufacture of the herbicide 2,4-dichlorophenoxyacetic acid.
Substance details
Substance name: Chlorophenols (di, tri, tetra)
CASR number: 25167-81-1, 25167-82-2, 25167-83-3
Molecular formula: C6H4Cl2O (CASR# 25167-81-1)
C6H3Cl3O (CASR# 25167-82-2)
C6H2Cl4O (CASR# 25167-83-3)
Synonyms: 2.4.6 T, 2.4.6-TCP, 2.4.6-Trichloro-2-hydroxybenzene, 2.4-DCP, 4.6-Dichlorophenol, Chem-Tol, Chlorophen, Collunosol, Cryptogil Oil, DCP, Dow Pentachlorophenol Dp-2 Antimicrobial, Dowcide 2S, Dowcide 7, Dowicide 2, Dowicide 2S, Dowicide 6, Dowicide 7, Dowicide Ec-7, Dp-2. 2.3.4.5.6-Pentachlorophenol, Durotox, Ep 30, Fungifen, Glazd Penta, Grundier Arbezol, Lauxtol, Lauxtol A, Liroprem, NCI-C54933, NCI-C55378, NCI-C56655, Omal, Pcp, Penchlorol, Penta, Pentachlorofenol, Pentachlorophenate, Pentachlorophenol, Pentacon, Penta-Kil, Pentasol, Penwar, Peratox, Permacide, Permagard, Permasan, Permatox Dp-2, Permatox Penta, Permite, Phenachlor, preventol I, Priltox, Santobrite, Santophen, Santophen 20, Sinituho, TCP, Term-I-Trol, Tetrachlorophenols, Thompson's Wood Fix, Weedone.
Physical properties
Di, Tri and Tetra Chlorophenol are part of a group of chemicals known collectively as chlorophenols. In total there are 19 different chlorophenols of which the di, tri and tetra forms make up 13. The chlorophenols differ in the number of chlorine atoms and also where the chlorine atoms are positioned in the atomic structure. Di, tri and tetra chlorophenol have 2, 3 and 4 chlorine atoms respectively Both the number and position of the chlorine atoms affect the overall properties. The 6 most commonly found forms are:
2,4-dichlorophenol (CASR#120-83-2)
2,4,5-trichlorophenol (CASR#95-95-4)
2,4,6-trichlorophenol (CASR#88-06-2)
2,3,4,5-tetrachlorophenol (CASR#4901-51-3)
2,3,4,6-tetrachlorophenol (CASR#58-90-2)
and 2,3,5,6-tetrachlorophenol (CASR#935-95-5).
Note: The numbers preceding the name denote the position of the chlorine atoms in the atomic structure.
All the chlorophenols in the in this group are solids (often needles and flakes). They have a strong medicinal taste and odour. Melting temperatures increase with the number of chlorine atoms. The dichlorophenols have melting temperatures around 50°C, the tri's around 70°C and the tetra's around 110°C. Boiling points vary but are generally above 150 or 200°C. 2,4,6-trichlorophenol sublimates (goes directly from solid to vapour).
Chemical properties
2,4-Dichlorophenol is white and is soluble in ethyl alcohol, carbon tetrachloride, ethyl ether, benzene, and chloroform. 2,4,5-Trichlorophenol, is grey and is soluble in acetone, benzene, carbon tetrachloride, ether, denatured alcohol, methanol liquid petrolatum, and chlorophenols (di, tri, tetra). 2,4,6-Trichlorophenol is yellow and is soluble in hot acetic acid, acetone, benzene, carbon tetrachloride, diacetone alcohol, methanol, chlorophenols (di, tri, tetra), turpentine, ether, and denatured alcohol formula. 2,3,4,5-Tetrachlorophenol is soluble in alcohol. 2,3,4,6-Tetrachlorophenol is light brown and is soluble in sodium hydroxide, hot acetic acid, acetone, alcohol, benzene, chloroform, and ligroin. 2,3,5,6-Tetrachlorophenol is soluble in benzene.
On combustion chlorophenols form toxic and corrosive gasses. Upon heating, toxic fumes are formed. Chlorophenols reacts violently with strong oxidants.
Further information
The National Pollutant Inventory (NPI) holds data for all sources of chlorophenols emissions in Australia.
Description
Not much is known about the behaviour of this group of chemicals in the body. Workers who made pesticides from chlorophenols and were exposed to chlorophenols through breathing or skin contact developed acne and mild liver injury and showed evidence of acquired blood, skin and hair disorders. Symptoms of exposure to concentrated forms of this compound include severe irritation and burns of the skin, eyes, mucous membranes and the upper respiratory tract. Other symptoms reported include tremors, convulsions, shortness of breath and inhibition of the respiratory system, vomiting, collapse, coma, painless whitening or reddening of the skin, profuse sweating, intense thirst, nausea, diarrhoea, blood disorders, hyperactivity, stupor, blood pressure fall, abdominal pain, fluid on the lungs followed by pneumonia, and occasional skin sensitivity reactions. Some of the chlorophenols are recognised as carcinogens.
Entering the body
Chlorophenols can enter the body by breathing, contact with the skin or by ingestion. When humans and animals eat food or drink water that contains chlorophenols, most of the chemical will be removed from the body within a few days.
Exposure
By contact with vapours in the air, skin contact with pure substances or substances that are contaminated or contain the compounds or by eating food or drinking liquids contaminated by chlorophenols. It is unlikely that persons will be exposed to pure substances except in laboratories. Ambient concentrations even in contaminated areas are generally very low.
Workplace exposure standards
Safe Work Australia sets the workplace exposure standards for airborne contaminants. There are no workplace exposure standards for NPI-listed chlorophenols.
Drinking water guidelines
The Australian Drinking Water Guidelines include the following guidelines for acceptable water quality:
2,4‑dichlorophenol
- Maximum of 0.2 milligrams per litre of water for health purposes
- Maximum of 0.0003 milligrams per litre of water for aesthetic considerations
2,4,6‑trichlorophenol
- Maximum of 0.02 milligrams per litre of water for health purposes
- Maximum of 0.002 milligrams per litre of water for aesthetic considerations
Description
The effects of chlorophenols on the environment are not well known. In high concentrations they can have immediate effects as with humans. This can include death of plants, animals, birds and fish. There is insufficient information to be able to determine longer term effects.
Entering the environment
Chlorophenols can be transported by air as a particle or vapour, in surface of ground water and also in solids and soil.
Where it ends up
In the environment, 2,4,6-trichlorophenol is found most frequently in water, especially near hazardous waste sites contaminated with 2,4,6-trichlorophenol. A combination of factors aid in the removal of 2,4,6- trichlorophenol from water. These include breakdown of 2,4,6-trichlorophenol by bacteria, some breakdown by the sun, evaporation of 2,4,6-trichlorophenol into the atmosphere, and its removal by attaching to other particles in water. This removal occurs in about 1 to 19 days. In sewage plants, it is broken down even more quickly by bacteria present in sewage.
Environmental guidelines
Australian Water Quality Guidelines for Fresh and Marine Waters (ANZECC, 1992):
2,4-dichlorophenol: Maximum 0.2 micrograms/L (i.e. 0.0000002g/L) in fresh water (no guideline for salt water).
Total trichlorophenol: Maximum 18 micrograms/L (i.e. 0.000018g/L) in fresh water (no guideline for salt water).
2,4,5-trichlorophenol: Maximum 8 micrograms/L (i.e. 0.000008g/L) in salt water (no guideline for fresh water).
Industry sources
Production sources of chlorinated phenols or waste burners. Other potential sources are from contaminated sites or sites that produce chlorinated organic compounds.
Diffuse sources, and industry sources included in diffuse emissions data
2,4,6-trichlorophenol produced from the breakdown of other chemicals may be found in wastewater, drinking water, and in soil. Fish and shellfish from areas near sewage releases or industries that use 2,4,6-trichlorophenol may build up 2,4,6-trichlorophenol in their tissues. Exposure to 2,4,6-trichlorophenol may occur through its use in pesticides, or wood, leather, or glue preservatives.
Natural sources
There are no natural occurring sources of these compounds.
Transport sources
These chemicals are not normally related to mobile vehicles and equipment.
Consumer products
Chlorophenols have been used as mothproofing agents, miticides, germicides, algicides, fungicides, pesticides and wood preservatives and may be found in these products.
Sources used in preparing this information
- Australian and New Zealand Environment and Conservation Council (ANZECC) (1992), Australian Water Quality Guidelines for Fresh and Marine Waters.
- Chemfinder (accessed, June 1999)
- Environmental Writer Chemical Backgrounders (accessed, June 1999)
- Meagher, D (1991), The Macmillan Dictionary of The Australian Environment, Macmillan Education Australia Pty Ltd.
- National Chemical Safety Cards (accessed, June 1999)
- National Environment Protection Council (1998), National Environment Protection Measure for the National Pollutant Inventory. (accessed, March, 1999)
- New Jersey Department of Health Hazardous Substance Fact Sheet (accessed, June 1999)
- Richardson, M (1992), Dictionary of Substances and their Effects, Royal Society of Chemistry, Clays Ltd, England.
- Sittig, M (1991), Handbook of Toxic and Hazardous Chemicals and Carcinogens, 3rd edition, Noyes Publications, USA.
- Technical Advisory Panel (1997), Report to the National Environment Protection Council.
- US Department of Health and Human Services (1990), NIOSH Pocket Guide to Chemical Hazards, Publication No. 90-117.
- US Environmental Defence Fund environmental scorecard (accessed, June 1999)
- US EPA technology transfer network (accessed, June 1999)
- US National Toxics Program (accessed, June 1999)
- Safe Work Australia, Workplace exposure standards for airborne contaminants, accessed September 2018.
- National Health and Medical Research Council (NHMRC), Australian Drinking Water Guidelines (2011) - Updated October 2017, accessed May 2018