Wood preservation facilities, alkaline copper quaternary: chapter G-6

6. Protection of Personnel

6.1 First Aid Precautions and Hygiene for ACQ Exposure

Human health effects could occur as a result of improper controls during preparation of ACQ; exposure to minor spills and residues in working areas; and improper handling of, in particular, freshly treated products. When exposure to a chemical occurs, the severity and speed of damage to human health depends on the concentration. The general rule is as follows: the higher the concentration of a preservative to which a worker is exposed, the greater the need for protective measures and immediate response if contact occurs.

Facility staff should have access to product labels and appropriate training to apply first aid.

Immediate response is required if a worker is exposed to ammonia copper, amine copper, quat or ACQ work solutions.

Artificial respiration should not be performed without the use of a barrier device, as the injured person may be contaminated (on skin) with ACQ solution, making the first aider the next victim if direct mouth-to-mouth contact is made.

Table 5 outlines first aid measures for exposure to ACQ and its constituents.

6.2 Regulatory Controls

The label for pesticide products contains information on the minimum necessary protective equipment and practices for using the product. The worker protection measures on the pesticide label are mandatory. Provincial or municipal regulations may require additional measures that may enhance, but not reduce, protection. Table 7 in Chapter A can be used to summarize the local regulatory threshold limit values (TLVs) and/or biological exposure indices (BEIs) applicable to the plant.

Specific limits for worker protection are generally prescribed by provincial regulations. Consult your local authorities for specific applicable regulations.

Most regulatory criteria established by worker protection agencies are based on TLVs and BEIs recommended by the American Conference of Governmental Industrial Hygienists (ACGIH). The ACGIH does not provide a recommended limit for ACQ, as such. The ACGIH-recommended limits for individual components (ammonia, copper and ethanolamine) are summarized in Table 4.0.

Skin and Eye Contact

In cases where ACGIH-recommended limits are based only upon “inhalation” as the route of exposure, these limits may not adequately take into account other routes of exposure.

Inhalation

The ACGIH has defined TLVs for many substances based on exposure by inhalation and/or skin exposure. The ACGIH limits for copper, amine and ammonia are based solely on exposure by inhalation. The TLVs are stipulated by the ACGIH as those “airborne concentrations of substances to which it is believed that nearly all workers may be repeatedly exposed day after day without adverse effects.” The TLVs for copper, ethanolamine and ammonia (24) are defined in Table 4.0, with the following provisos of the ACGIH:

• “The limits are intended for use in the practice of industrial hygiene as guidelines for good practices or recommendations in the control of potential health hazards and for no other use” (i.e. proof or disproof of the cause of an existing disease or physical condition).
• “The limits are not fine lines between safe and dangerous concentrations.”
• “In spite of the fact that serious injury is not believed likely as a result of exposure to the Threshold Limit concentrations, the best practice is to maintain concentrations of all atmospheric contaminants as low as is practical.”
• “When two or more hazardous substances, which act upon the same organ system, are present, their combined effect, rather than that of either individually, should be given primary consideration.”

Ingestion

Oral intake of ACQ must be avoided. Ingestion of liquids containing ACQ is unlikely if workers follow the safety precautions outlined in Table 8. Upper limits of ingestion are not prescribed by regulation, because it is generally expected that no such intake will occur. Reported fatal single dose levels for some components of ACQ include 30 ml of 25% ammonia solution (26); and 1.5-3.5 g of copper as copper ⁺¹ (27).

6.3 Safety Precautions

Workers need to familiarize themselves with the safety precautions listed in Table 8 in addition to those recommended in Chapter A, Section 6.3. Sensitive individuals should take special care to avoid exposure.

6.4 Biological Monitoring of Exposed Workers

Biological monitoring is a useful tool for evaluating the long-term effectiveness of the protective measures applied. Routine biological monitoring of exposed workers (primarily those who handle preservatives and treated wood, e.g., plant operators and quality control personnel) is recommended. Refer to Chapter A, Section 6.4